NHM 253 NHM 253
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This 142 page Bundle was uploaded by Ian Spath on Tuesday February 10, 2015. The Bundle belongs to NHM 253 at University of Alabama - Tuscaloosa taught by McMahon in Spring2015. Since its upload, it has received 374 views. For similar materials see Food Science in Nutrition and Food Sciences at University of Alabama - Tuscaloosa.
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Date Created: 02/10/15
Chapter 1 INTRO Making Food Choices Senses taste touch smell sight sound Religious values Kosher foods Psychological Emotion comfort food Budget lobster vs canned tuna Personal Preference Instantaneous evaluation of sensory characteristics Biased by culture emotion psychological preference Not an appropriate standard for sensory evaluation Volatile molecules Molecules capable of evaporating like a gas into the air Olfactory Relating to the sense of smell SIGHT Provides first impression Color Ripeness black bananas green strawberries Length of time food was heated burned chicken rare steak Presentation Baked fish steamed white rice boiled cabbage vanilla ice cream Grilled chicken orange sweet potatoes steamed green beans blueberry cobbler ODOR 39 Smell is second only to taste when choosing a food Two classification systems 6 groups spicy flowery fruity resinous eucalyptus burnt and foul 4 groups fragrant sweet acid sour burnt and caprylic goaty TASTE Taste is the deciding factor in food selection Components of Taste Volatile and nonvolatile substances Taste buds Cellular structure resembles a flower bud Found on the underside side tip of the tongue palate and pharynx 5 Basic Tastes Sweet Salty Sour Bitter Savoryumami Gustatory Relating to the sense of taste FLAVOR Combination of the sense of taste odor and mouthfeel Aroma accounts for 75 of flavor Mouthfeel Sensation detected by the lining of the mouth as it interacts with food Fat content of foods affect flavor and mouthfeel Watersoluble ingredients Sugar salt soy sauce Fatsoluble ingredients Butter oils chocolate TOUCH Texture A combination of sight touch and mouthfeel Via teeth tongue and palate Tenderness How easily food gives way to the pressure of the teeth Consistency Different than tenderness Astringency Pucker power Chemethesis Feel foods chemical properties HEARING Example Sizzling entrees offered by Applebee s and TGI Friday s Descriptive Terms sizzling popping crackling bubbling pouring hissing crunch Water content affects the sound a food makes Sound relays messages about ripeness doneness and texture Descriptive Terms Appearance Symmetrical asymmetrical level sunken round pebbled sticky greasy shiny dry pale golden smooth rough puffy transparent dark creamy curdled dull fine grainy moist opaque glossy Flavor Sweet bitter sour salty astringent spicy soapy floury flat eggy rancid pasty bland flowery fruity sharp burnt minty pungent musky puckery putrid metallic peppery fishy nutty yeasty Food group plan A dietplanning tool that groups foods together based on nutrient and calorie kcal content and then specifies the amount of servings a person should have based on their recommended calorie kcal intake Antioxidant A compound that inhibits oxidation which can cause deterioration and rancidity Nutraceutical A bioactive compound nutrients and non nutrients that has health benefits Functional food A food or beverage that imparts physiological benefits that enhance overall health prevents or treats a disease or condition andor improves physicalmental performance Texture Crisp velvety smooth rough hard firm thick thin viscous springy gritty gummy adhesive moist tender fibrous chewy pasty crunchy creamy gelatinized limp mealy crusty Mouthfeel Crisp sticky slimy gritty slick crunchy smooth Monograph A summary sheet fact sheet describing a substance in terms of name common and scientific chemical constituents functional uses medical and common dosage side effects drug interactions and references Nutrigenomics A field of study focusing on geneticallydetermined biochemical pathways linking specific dietary substances with health and disease Culture The ideas customs skills and art of a group of people in a given period of civilization Judaism The kashruth is the list of dietary laws adhered to by orthodox Jews Kosher dietary laws focus on three major issues 1 Kosher animals allowed 2 Blood not allowed 3 Mixing of milk and meat not allowed Kosher From Hebrew food that is fit right proper to be eaten according to Jewish dietary laws Halal An Arabic word meaning permissible Usually refers to permissible foods under Islamic law Islam Worldwide there are over 1 billion Muslims compared to 13 million Jews The Koran the divine book of Islam contains the halal dietary food laws recommended for Muslims that describe halal permitted or haram prohibited foods The five major areas addressed by the halal follow 1 Animals not allowed 2 Blood not allowed 3 Improper slaughtering method 4 Carrion decaying carcass not allowed 5 Intoxicants not allowed Biotechnology Previously called genetic engineering this term describes the alteration of a gene in a bacterium plant or animal for the purpose of changing one or more of its characteristics Genetically modified organisms GMOs Plants animals or microorganisms that have had their genes altered through genetic engineering using the application of recombinant deoxyribonucleic acid rDNA technology Gene A unit of genetic information in the chromosome Foods Created with Biotechnology Food biotechnology has so far resulted in benefits that increase the food s resistance to the following Pests less pesticide required Disease lower crop losses Harsh growing conditions drought salty soil climate extremes Transport damage less bruising allows more produce to make it to market Spoilage longer shelf life Foods using biotechnology can be categorized as one of the following 1 Actual food eg corn 2 Foods derived from or containing ingredients of actual food eg cornmeal 3 Foods containing single ingredients or additives from GMOs eg amino acids vitamins colors 4 Foods containing ingredients obtained from enzymes produced through GMO foods Concerns About Food Biotechnology Allergies Gene Contamination ReligiousCultural Concerns Chapter 1 Review Questions 1 The word olfactory is most closely related to which of the following senses a taste b smell c touch d sight 2 Total daily calorie kcal needs for adults decrease by calories kcals for every decade in people after age 40 100 200 300 400 00 03951 00 Which of the following religions encourages a vegetarian diet Buddhism Hinduism SeventhDay Adventist all of these QOC39Q A Identify the correct statement about genetically engineered foods Genes are programmed by sequencing the amino acids Food can be genetically engineered to delay ripening In the United States all genetically engineered foods must be labeled Not a single genetically engineered food has been approved by the FDA Q0 03951 O l Which of the following functional food examples is categorized as a medical food Tomatoes rich in lycopene Glutenfree foods Folateenriched breads Phenylketonuria PKU formulas free of phenylalanine QOC39Q 6 How many calories kcal equal a pound of body weight a 500 b 1000 c 2500 d 3500 7 A produce grower may place the USDA Organic label on a product it or more of the ingredients are organic a 5000 b 75 C 8500 d 95 Chapter 14 Classification of Fruit Simple fruits Develop from one flower and include drupes pomes and citrus fruits oranges grapefruits lemons limes kumquats and mandarins tangerines and tangelos Aggregate fruits Develop from several ovaries in one flower They include blackberries raspberries and strawberries Multiple fruits Develop from a cluster of several flowers Pineapples and figs are two examples Fruit The edible part of a plant developed from a flower Drupes Fruits with seeds encased in a pit Examples are apricots cherries peaches and plums Pomes Fruits with seeds contained in a central core Examples are apples and pears Albedo The white inner rind of citrus fruits which is rich in pectin and aromatic oils Composition of Fruit Basic Composition CHOs minimal amount of protein and fat vitamins minerals and nonnutritive substances Distinguishing feature between fruits and vegetables Higher sugar content 1015 of their weight as sugar Vegetables 35 of their weight as sugar Acidity browning shelf live extension and mold inhibition Organic Acids acids which impart tartness to fruits fruits also serve as a preservative Pectic Substances polysaccharides between cell wall and membrane which imparts strength and firmness to plants Phenolic Compounds plant metabolites essential in growth and repair of plant cells Organic Acids Acidity varies with plant maturity Average pH range of fruit 2 to 5 Most organic acids decrease as fruit ripens Functional Role serve a preservative mechanism Inhibit microbial growth on the fruits themselves At immature states fruits are very tart and have a low pH Classified as volatile vaporize during heating or nonvolatile do not vaporize during heating but they can leach out when fruit is cooked in water Common Organic Acids Citric acid in citrus fruits and tomatoes Malic acid in apples apricots cherries peaches pears and strawberries Tartaric acid in grapes Oxalic acid in rhubarb Benzoic acid in cranberries Pectic Substances Pectin is the molecule which contributes gelling properties of fruit Based on waterholding capacity of methyl pectate within pectin molecule Molecules align and entrap water Uses of Pectin in the Food Industry Three Basic Types of Pectic Substance protopectin immature fruit no gel pectin Ripe fruit gels pectic acid overripe fruit no gel Enzymes responsible for fruit ripening aid in breaking down protopectin to pectin Phenolic Compounds Compounds essential to growth and repair of plant cells Increasing research attention focusing on the antioxidant properties of phenolics Responsible for browning and bruising of ripened fruit known as enzymatic browning Enzymatic Browning Phenolic compounds will react with polyphenol oxidase enzymes to produce brown pigments This browning reaction is known as enzymatic browning and it takes place in the presence of oxygen Consider a cut apple 1 Phenolic compounds and enzymes in fruit are separated by cell walls 2 Dropping fruit injures cell structure just as slicing fruit cuts through cell structure Both actions cause phenolics and enzymes to come in contact with each other and with oxygen 3 Phenolics enzymes oxygen BROWNING Preventing Enzymatic Browning gt Temperature heat denatures the enzymes as in cooking and cold temps slow the rate of enzyme activity Keep ripe fruits in the refrigerator Technique used to denature enzymes blanching gt Enzyme activity is inhibited by low pH Example food acids to be mixed with cut fruit cut apples with vinegar lemon juice or sprite gt Preventing Enzymatic Browning gt Coating cut fruit with sugar or syrup BLOCKS oxygen from coming in contact with phenolics or enzymes gt Addition of food antioxidants or sulfur compounds to react with oxygen and prevent 02 from reacting with phenolics and enzymes gt Lemon juice is an example of a food antioxidant due to its content of ascorbic acid Pineapple juice naturally contains sulfur to prevent the browning Both are also acidic Components of Interest in Functional Foods Antioxidants photo chemicals Phenolic Compounds assist with levels of oxidative stress Fiber Aromatic compound A compound that has a chemical configuration of a hexagon Essential oil An oily substance that is volatile easily vaporized with 100 times the flavoring power of the material from which it originated Common Additives for Preservation Ingredients added to inhibit enzymatic browning Sulfates sorbates benzoates Sensitivity of sulfites Sulfites must be declared on product labels fresh fruit exception includes use on grapes Antifungal agents and other preservatives are also commonly used What commonly consumed beverage was recently recalled due to the presence of antifungal agents Orange Juice Changes in Fruit During Ripening Just as vegetables continue to respire fruit undergoes the following changes during ripening 1 Decrease in acid content loss of sourness 2 Starch converted to glucose causing increases in sugar content 3 Formation of volatile compounds like ripening hormone Ethylene 4 Destruction of chlorophyll unmasking secondary pigments 5 Softening in texture as pectic substances break down Fruit Ripening Fruits differ in respiration rate and thus their rate of ripening Some fruits are best ripened on the plant whereas others continue to ripen after harvest Those that continue to ripen after harvest are known as CLIMACTERIC fruits Ethylene is the ripening hormone associated with fruit maturation Fruit Ripening on the vine or off Climacteric Fruits continue to ripen after harvest Apple Apricot Avocado Banana Breadfruit Cantaloupe Guava Peach Pear Plum Tomato and Tropical fruits papaya mango passion fruit NonClimacteric Fruits best ripened before harvest Blueberry Cherry Citrus fruits grapefruit lemon orange Grapes Melons Olives Pineapple and Strawberry Changes in Composition During Heating pH Changes why would pH change during heating Textural Changes Conversion of protopectin to pectin Degradation of cellulose and hemicellulose Denaturation of cell membrane proteins which alters fruit turgor Osmosis amp Fruit Texture Osmosis a movement of water molecules through a selectively permeable membrane into a region of high solute concentration Solutes dissolved in solvents salts and sugars Fruits contain sugar Manipulating Fruit Texture via Movement of Water Addition of Water As water moves from an area of low solute concentration sugar to a higher one water is drawn into fruit cells causing swelling or plumping of the fruit Example misters at the grocery store also many of your commodities that under go a wash step in minimal processing will be submersed in water primary reason and to wash off any debris secondary reason The primary reason is to allow for water to come in contact with the skin which is by nature a semi permeable membrane and it causes the water molecules on the outside to draw into the cell of the commodity and plump the commodity so it looks fresher to the consumer eye appeal Addition of Sugar What is the effect of sprinkling sugar on the outside of the fruit for example cut pears or apples Example Application To mix cut fruit to make a sugar syrup Storage amp Handling of Fruits To hasten the ripening of climacteric fruits place them in a paper bag with a bruised banana Why The bruised banana is releasing ethylene The ethylene must be contained Once fruits are fully ripe storage time may be increased by loosely covering with plastic bag and placing in the refrigerator Exception to this guideline bananas because they will brown Like vegetables fruit Should always be washed or rinsed well before eating Should be cooked with minimal heating to presene nutrient content Chapter 14 Review Questions 1 a b c d 2 What is the term used to describe fruit with seeds contained in a central core such as apples and pears Drupes Frumps Seed cores Pomes Identify the correct order for the chemical breakdown of protopectin as a fruit changes from immature to overripe U l QOC39Q lgt 006513 00 005 051 00 Protopectin to pectin to pectic acid Protopectin to pectic acid to pectin Protopectin to oxalic acid to pectin Protopectin to pectin to oxalic acid The peels of which fruits are commonly used as zest to add flavor Kiwifruit watermelon Lemon orange lime Grapes watermelon Banana dates mangoes Jams are best described as fruit preserves made from ground or mashed whole cooked fruit whole fruit halves or chunks the juice of cooked fruit with added sugar and pectin the juice of fruits with thin slices of fruit and rind A fruit juice beverage that contains not less than 30 to 40 percent fruit juice would be classified as an juice drink nectar ade juice l QOC39Q QOC39Q Fruits are generally low in fat with three exceptions that include avocados coconut and olives figs dates and guava olives coconut and pomegranates dates avocados and dried fruit What fruit medium size has more vitamin C than a mediumsized orange Papaya Kiwifruit Strawberries 1 cup All of these choices Chapter 5 Cooking Methods Dictate the type of heat transfer which determines a recipe s Speci c texture Appearance Aroma amp Flavor Often determine how the recipe will be named Foods can be cooked in air fat steam or water Moistheat preparation A method of cooking in which heat is transferred by water any water based liquid or steam Poaching Simmering Boiling and Steaming Scalding reaches a temperature of 150F 66 C It is indicated by the appearance of large but relatively still bubbles on the bottom and sides of the pan This process was most frequently used with milk to improve its function in recipes and to destroy bacteria Poaching Water heated to a temperature of 160 180F 71 82 C is used for poaching in which the food is either partially or totally immersed The water is hotter than it is at scalding but has not yet reached the point of actually bubbling Convection Heat Transfer Simmering Water simmers at just below the boiling point never less than 180F 82 C Simmering is characterized by gently rising bubbles that barely break the surface Many food dishes especially rice soups and stews are rst brought to a boil and then simmered for the remainder of the heating time Simmering is preferred over boiling in many cases because it is more gentle and will usually not physically damage the food and foods will not overcook as quickly as they do when boiled Convection Stewing refers to simmering ingredients in a small to moderate amount of liquid which often becomes a sauce as the food cooks Most stew dishes consist of chopped ingredients such as meat often browned rst and vegetables placed in a large casserole or stock pot with some water stock or other liquid Conduction and convection Braising similar to stewing in that food is simmered in a small amount of liquid in a covered casserole or pot The liquid may be the food s own juices fat soup stock andor wine Combination Boiling In order to boil water must reach 212F 100 C at sea level a temperature at which water bubbles rapidly Convection Parboil To partially boil but not fully cook a food Steaming Any food heated by direct contact with the steam generated by boiling water has been steamed Cooked vegetables are at their best when steamed because this method helps to retain texture color taste and nutrients Convection Microwaving incorporates both dry radiation and moist heat preparation methods Microwaves are a form of radiation aimed at the water in the food or beverage Blanch To dip a food brie y into boiling water Dryheat preparation A method of cooking in Which heat is transferred by air radiation fat or metal Dry Heat Methods POSITION USED FOR Oven Rack Position RACK 5 Toasting bread or for tworack baking RACK 4 Most broiling and tworack baking RACK 3 Most baked goods on a cookie sheet or jelly roll pan or frozen convenience foods or for tworack baking RACK 2 Roasting large cuts of meat and large poultry pies souffl s or for tworack baking RACK 1 Roasting large cuts of meat and large poultry pies souffl s or for tworack baking Use air or fat as the heat transfer medium 0 Roasting and Baking Broiling and Grilling 0 Frying 0 Sauteing Pan frying 0 Stir frying Deep frying Roasting Process of heating food in dry heated air in closed environment Roasting applies to meats and poultry Radiation 1st and Convection 2nd Baking Process of heating food in dry heated air in closed environment Baking applies to sh fruit vegetables starches and breads Radiation 1st and Convection 2nd Saut ing Uses a small amount of fat to minimally cover the bottom of the pan Heat is transferred to the food via conduction Food should be as dry as possible to prevent spattering and aid in browning Stirfrying is a variation of saut ing Uses a wok instead of a saut pan Constant high heat Conduction Boiling To broil is to cook foods under an intense heat source The high temperatures of broiling cook foods in approximately 5 to 10 minutes so only tender meats poultry and sh are broiled tougher foods require longer heating times Temperature is controlled by moving the rack closer to or farther away from the heat source Thicker cuts are broiled farther from the heat thinner ones closer on the fourth or fth rack up from the bottom of a home oven Convection Grilling the reverse of broiling in that food is cooked above rather than below an intense heat source The grill may be a rack or a at surface on a stove Radiation Barbecuing Barbecuing now refers to foods being slow cooked usually covered in a zesty sauce over a longer period of time The temperature in barbecuing is regulated by adjusting the intensity of the heat source charcoal wood gas or electric adjusting the distance between the food and the heat source and moving the food to different places on the grill Frying Heating foods in fat Oils used in frying serve to transfer heat act as a lubricant to prevent sticking and contribute to avor browning and a crisp outside texture Pan Frying 0 Uses enough fat to come 13 to 12 way up sides of pan 0 Fat should be at a temperature lower than saut ing 0 Foods are usually breaded prior to pan frying 0 Upon cooking drain on paper towels and serve immediately Conduction 1st and Convection 2nd Deep Frying 0 Food is submerged in oil frying medium 0 Although similar to boiling deep frying is not a moist heat cooking method 0 No water ALL fat 0 Relies on temperatures up to 400F 0 Points to consider 0 uniform size 0 recovery time best to rely on the fryer s thermostat to obtain the desired temperature Deep Frying Frying Medium Smoke Point temperature at which fat breaks down to glycerol and free fatty acids 0 Glycerol breaks down to acrolein eye irritant 0 Prevention select an oil with high smoke point relevant to temperature used to fry Flash Point lowest temperature at which fat can form an i gnitable vapor in air Maintaining Frying Oil Store tightly sealed away from light Skim or lter out fried particle Use minimum salt amp leavenings in coatings Minimize water content of food Do not overheat the fat Convection Baste To add a liquid such as drippings melted fat sauce fruit juice or water to the surface of food usually roasting meat to help prevent drying Sear To brown the surface of meat by brief exposure to high heat Combination Methods Uses both dry and moist heat by browning food rst in fat and then nishing the cooking in a liquid Dry heat saute Moist heat simmer Braising used with large meat portions whole roasts Conduction and convection Stewing used with small bite sized pieces Conduction and convection Conduction The direct transfer of heat from one substance to another that it is contacting Example saute pan over a gas ame conducts heat to the surface of the food lying in the pan Some materials conduct heat better than others Good conductors Copper is an excellent heat conductor and is often used to line the bottom of stainless steel pans Poor Conductors Air Heat Transfer Within Foods gt Occurs via conduction as food molecules absorb heat energy causing molecules to move and bounce gt Creating friction as they collide with other molecules gt Transferring energy between adjacent molecules gt Physical contact between molecules transfers heat energy within food Convection The transfer of heat by moving air or liquid waterfat currents through andor around food Example movement of water molecules heated in a stockpot Two types of convection Natural Mechanical Heat Transfer via Radiation 0 Transfer of heat energy as waves of heat or light striking food surfaces 0 Types of Radiant Heat Infrared Infrared heat lamps and ovens are other heat sources that use electromagnetic waves for heat Microwave The short electromagnetic waves that are generated by microwave ovens can pass through glass paper and most plastic Induction The transfer of heat energy to a neighboring material without contact Kinetic energy Energy associated with motion Calorie kcal The amount of energy required to raise l kilogram of water 1 C measured between 145 C and 155 C at normal atmospheric pressure Carryover Cooking 0 Cooking that occurs Within a food as it continues to increase in temperature after removing from heat source 0 Result of residual heat left in food 0 Important point to consider With regard to doneness especially in meats Knives 0 One of the most important tools in the kitchen 0 Different kinds of knives Chef s or French knife 0 Largest most versatile 0 Cut and crush foods Paring knife 0 Smaller 2 4 in length 0 Delicate tasks Utility Knife The utility knife is geared toward lighter duties such as cutting tomatoes or carving meat Boning Knife The slightly curved boning knife is handy for separating meat from bone eg deboning the breast of a chicken disjointing poultry cutting between the joints of larger pieces of meat and dicing raw meats Slicing Knife Slicing knives are long and exible enough to portion off thin slices of meat or poultry Serrated slicers are useful for cutting bread or angel food cake Steak or Scimitar Knife These knives are used for cutting steaks from the appropriate parts of a carcass Butcher Knife A variety of butcher knives are available for cutting raw meats Heavy Cleavers Additional knives that are found in food service arenas include heavy cleavers for cutting through bone Oyster and Clam Knives Oyster and clam knives are used for opening these shell sh The Blade 0 Different sections of the blade can be used for different tasks 0 Tip Light work slicing mushrooms 0 Blade 0 Middle Most other tasks 0 BaseHeel Heavy work chopping More weight and thickness to the food Handling Knife Grip 1 Hold base of knife between thumb and fore nger 2 Wrap remaining around the handle Food Grip 1 Curl guide hand and tuck the thumb 2 Keep 12 between the blade and ngers Knife Safety 0 The 1st rule of knife safety is to think about what you are doing 0 Use the correct knife for the task at hand 0 Always cut away from yourself 0 Always cut on a cutting board NOT on glass or metal 0 Always use a sharp knife a dull knife is more dangerous 0 When carrying a knife hold it point down parallel and close to you as you walk 0 DO NOT TRY AND CATCH A FALLING KNIFE it has no handle just let it fall 0 NEVER leave a knife in a sink of water anyone reaching in sink could cut themselves and the knife could be dented by pots and pans Cuts o The goal of cutting food is to produce uniform shapes and sizes Why is this important This is important because it allows for even heating and gives food an appetizing appearance 0 Slice To move the food under the blade while keeping the point of the blade rmly on the cutting board Julienne To cut food lengthwise into very thin stick like shapes Chiffonade shredding Rondelles Diagonals Butter y 0 Dice To cut food into even size cubes 0 Mince To chop food into very ne pieces 0 Peel To remove the skin Knife Care Wash in hot soapy water immediately after task is complete Store knives so that blades do not touch each other or other utensils that may nick the blade Plasticity The ability of a fat to be shaped or molded Seasoning Any compound that enhances the avor already found naturally in a food Flavoring Substance that adds a new avor to food Herb A plant leaf valued for its flavor or scent Spice A seasoning or flavoring added to food that is derived from the fruit flowers bark seeds or roots of a plant Rhizome An underground usually stem that generates 1 shoots that rise up andor horizontally to propagate new plants and 2 roots that grow down to the ground Sweat The stage of cooking in which food especially vegetables becomes soft and translucent Chapter 5 Review Questions 1 In which cooking method is food simmered in a small amount of liquid in a covered pot or casserole dish Braising Scalding Simmering Steaming 000quot 3 Food that is cut into very thin sticklike shapes has been chopped n nced peebd juHenned QOC39Q OD Three teaspoons is equivalent to 1 tablespoon 1 tablespoons 2 tablespoons 2 1stablespoons 000quot A When using the muffin method of mixing overmixing will produce what type of unwanted result Tender Tough Overly moist Overly dry Q0 03951 O l What is the best environment for storing herbs and spices A moist place A warm bright place A cool dry place A hot moist place 00551 03 Which of the following heating methods is based on the principle of conduction Heat from an electrical coil or gas flame touches a pan that heats the pan s contents Heated air in an oven rises and cooler air moves downward Heat is transferred by waves during grilling broiling and microwaving Heat is moved from the coils under a flatsurfaced range to the pot 000quot l The correct sequence for breading is egg wash flour crumbs flour crumbs egg wash egg wash crumbs flour d flour egg wash crumbs OC39QJ Chapter 13 Notes Classification of Vegetables roots carrots beets turnips and radishes bulbs onions and garlic stems celery and asparagus leaves spinach and lettuce seeds beans corn and peas flowers broccoli and cauliflower In addition there are foods that are routinely called vegetables and used as vegetables but that are actually fruits Botanically fruits are the part of the plant that contains its seeds specifically the mature ovaries of plants If it derives from a flower then it is usually a fruit The fruits most often seen masquerading as vegetables include tomatoes squash cucumbers avocados okra eggplant olives water chestnuts and peppers Composition of Vegetables Vegetables contain CHOs small amount of protein incomplete vitamins minerals and nonnutritive substances CHO in the form of starch fiber or sugar Fiber cellulose hemicellulose pectic substances gums and lignin nonCHO fiber Fiber provides structural support for plants and gastrointestinal support for humans NonNutritive Substances Plant pigments aka photochemicals Structure amp Composition of Plant Cells vs Animal Cells Turgor The rigid firmness of a plant cell resulting from being filled with water It provides the texture and crispness to vegetables It is very important for plants to have a double layer cell membrane in order to maintain turgor and not collapse or burst from the shear amount of pressure that is exerted on those cells by the trapped water within They differ in membrane fluidity structure and pH levels Each one plays a major role in the integrity of a plant cell and in the texture and sensory qualities of a plant cell as well as the nutritive value of a plant Double layer membrane around the plant cell and within that membrane there is a lot of cellulose and hemicellulose two indigestible fibers Plant cells are very effective in containing the organic acids within the cells These organic acids contribute characteristic flavor and crispness to the plant It s very important that those organic acids stay compartmentalize It s not as fluid and does not allow for the movement of organic acids and liquids of one compartment to another If it did there we would see major changes in pigmentation of plants growing on the vine or tree It s important the pH and the organic acids are imparted by pH to the plant It s important that these stay compartmentalized When we drop a banana on the floor or bruise it we are slicing through those cells and the organic acids are released We begin to see browning reactions therefore the structure of a plant cell based on the fact it contains great amounts of fiber allows it to balance the roll of fluidity turgor imparts structure characteristics which maintains integrity of the plant and compartmentalize the organic acids which keeps the strong acidic organic acids away from pigments in order that those pigments might maintain their full capacity in nutritive value Three Classes of Plant Pigments Carotenoids alpha beta and gammacarotenes account for most of the yellow orange and some of the red color of fruits and vegetables Carotenes lend reddishorange yelloworange color to carrots and winter squashes Lycopenes which are a deeper red redorange provide the bright color of tomatoes Light yellow xanthophyll pigments color pineapples Zeaxanthin Carrots Oranges Peaches Pineapples Pink grapefruit Red and yellow peppers Tomatoes Watermelon and Winter squashes Heat affects the color of vegetables most likely because it modifies the pigments chemical structure Exposure to oxygen also causes oxidation of pigments and a resulting loss in color Vegetables containing betacarotene should not be overheated because this pigment not only contributes to color but can also be converted to vitamin A therefore its destruction would be doubly undesirable pH stable in acid or alkali conditions Most stable pigment through the cooking process Chlorophyll Chlorophyll a bluegreen amp Chlorophyll b green the pigment responsible for the green color of plants also makes possible the essential process of photosynthesis in which leaves capture the sun s light energy to convert carbon dioxide and water to carbohydrates It is not surprising that plants rich in chlorophyll include most of the leafy green vegetables such as lettuce spinach broccoli green cabbage and kale Chlorophyll Chemistry Pigment Stability as Influenced by Heat stable with minimal heat yet unstable with prolonged heating Why do greens become duller in color with prolonged cooking Prolonged cooking and exposure to heat opens the molecular structure and it influences the cellular compartmentalization that has been reserving organic acids in their own compartments As the structure begins to open those organic acids are released in the medium Pigment changes from chlorophyll to pheophytin pH unstable in acid yet stable in alkali conditions Prepare green vegetables uncovered Why Flavonoids Anthocyanins redpurple and blue Eggplant Radish Red Cabbage Red Potato The color of the anthocyanins in these foods is affected by several factors including changes in pH that may occur during simmering Acidic tap water intensifies the red color of anthocyanins alkaline water changes the reddishblue hue first to an unappetizing blue and then to green Anthoxanthins creamwhite Cauliflower onions rice turnips and white potato composite of compounds known as flavones flavonols and flavonones They are the reason for the cream or white color of cauliflower onions white potatoes and turnips Further whitening can be achieved by adding acidic ingredients such as cream of tartar or vinegar Anthoxanthins turn an undesirable yellow color in alkaline water and can even change to blueblack or redbrown under excessive heating or in the presence of iron or copper Betalains purpleredyellow Beets Betalain pigments red betacyanins and yellow betaxanthins give beets their deep purplishred color It is important to leave beets unpeeled until after they are cooked in order to prevent their rich color from bleeding out into the water For the same reason 1 or 2 inches of stem should be left at the top during cooking Acidic ingredients such as vinegar convert the purplishred hue of beets to a brighter red In an alkaline medium the red color shifts to yellow Impact of Pigment Stability Heat opens the molecular structure and begins some of the fibrous compounds At this time a lot the cellular integrity and the oompartmentalization within the plant is lost The organic acids have been released and nutrient value has been lost Oxygen browning reactions such as a cut apple and pigment oxidation pH organic acids When these acids loose their oompartmentalization abilities based on heat and dropping banana those organic acids mixed with enzymes enzymes are involved in denaturation and can alter pigments stability Impacts of Heat during Cooking Texture softens carbohydrate and matrix Water is also being lost Decrease in turgor and rigidity Flavor opening of molecular structures better flavor because the cellular compartments that house the organic acids begin to open and release those organic acids which allows a lost of sharpness and bite Heat have a positive impact on cooking because it decreases the acidity and allows this carbohydrate matrix to accept other flavors such as spices and marinades Odor influenced by the amount of heat which is prominent in the white vegetables garlic and onion It can cause an increase in odor perception especially with sulfur containing vegetables Color decrease in intensity of most cooked vegetables Nutrient Retention based on the amount of exposure Cruciferous A group of indole containing vegetables named for their crossshaped blossoms they are reported to have a protective effect against cancer in laboratory animals Examples include broccoli brussels sprouts cabbage cauliflower kale mustard greens rutabaga kohlrabi and turnips Legumes Members of the plant family Leguminosae that are characterized by growing in pods Vegetable legumes include beans peas and lentils Selection amp Prep Most grading of vegetables is voluntary by USDA Seasonality influences optimum taste and texture Washing of vegetables is must Peel slice amp dice only if necessary Pieces should be uniform in size and shape to ensure even cooking Highest concentration of nutrients is located immediately beneath the skin of veggies and fruit Remove minimal peel to preserve nutrient content Cooking amp Nutrient Retention Roasting works best with thickskin vegetables Why Parboiling helps decrease cook time at roasting temperature Boiling most commonly used yet accounts for high nutrient losses Simmering preserves more nutrients due to lower heat Steaming best method for retention of nutrients Minimal effect of water on leaching of pigments or pH of water for influencing pigment leaching Microwaving good retention of nutrients due to minimal water and short time Vegetable Storage Two primary factors influencing shelflife Continued respiration Loss of moisture Ways to Prolong Shelflife Slow respiration and activity of enzymes via low temperature storage Store in a humid environment crisper drawer Freezing vegetables should be blanched first before freezing Why Slows down the chemical changes and enzyme activity Dry Storage ONLY Tomatoes especially unripened toms Eggplant winter squash tubers like potatoes and yams dried legumes and most bulbs like garlic or onions Legumes Plant Part seeds contained within pods Beanspeasand lentils are an excellent source of protein fiber and complex CHOs What is a commonly consumed legume that is also used as an ingredient in many commercial foods Why is this legume unique Soy and peanuts are commonly consumed legumes and they are both allergens VegetableBased Meat Alternatives TVPTextured Vegetable Protein is dehydrated plant protein material that is commonly used as a meatalternative Commonly used as meat extenders Available in a variety of meat options USDA limits TVP to 30 of a product Tofucurd made from soy milk Precipitated and coagulated in a manner similar to dairybased cheese Excellent protein source for vegetarians Au gratin Food prepared with a browned or crusted top A common technique is to cover the food with a bread crumbsauce mixture and pass it under a broiler Scalloped Baked with milk sauce and bread crumbs Degorge To peel and slice vegetables sprinkle them with salt and allow them to stand at room temperature until droplets containing bitter substances form on the surface the moisture is then removed Specific gravity The density of a substance compared to another substance usually water Respiration rate The rate of carbon dioxide produced from a given amount of produce over a certain unit of time Chapter 13 Review Questions 1 Which of the following would be classified as a root vegetable Asparagus Broccoli Carrot Garlic 00551 3 Carotenoids found in vegetables are susceptible to damage from which of the following factors Light Heat Oxygen All of the above QOC39Q OD What is the name of the pigment responsible for the green color of plants Carotene Chlorophyll Lycopene Xanthophyll Q0 03951 4 Broccoli cabbage cauliflower and kale belong to the family of vegetables that may have protective effects against cancer carotenoid phytochemical fibrous cruciferous QOC39Q O l Tempeh is the name of a meat alternative made from whole that have been fermented pinto beans soybeans lentils navy beans Q0 03951 03 Legumes are a group of vegetables that include tomatoes eggplant and zucchini potatoes peppers and beets brussels sprouts cabbage and cauliflower beans peas and lentils QOC39Q Which vegetable should not be stored in the refrigerator Potato Carrots Bean sprouts Squash QOC39Q Chapter 16 Grain Structure amp Composition Husk protective outer coating that is often processed into fiber supplements Bran protective coating of the endosperm High in fiber B vitamins minerals Endosperm starch house of the grain Uses of Cereal Grains w Flour wheat is the predominant choice due to its protein content and ability to provide structure to baked goods w Pasta w Breakfast Cereal primarily made from wheat corn and oats w Alcoholic Beverages made through fermentation of rice barley rye or corn Animal Feed Whole grains Defined by the American Association of Cereal Chemists AACC as Foods made from the entire grain seed usually called the kernel which consists of the bran germ and endosperm Fermentation The conversion of carbohydrates to carbon dioxide and alcohol by yeast or bacteria Classification of Cereal Grains Whole Grains Contain the entire grain kernel bran germ endosperm Composed of intact ground cracked or flaked kernel Examples Whole Wheat Flour Bulgur Oatmeal and Brown Rice Refined Grains Grains that have been milled to remove the bran and germ Endosperm only Finer texture with increased shelflife Why Foods with higher fat tend to go rancid much more quickly If the germ is removed this will increase the shelflife Removes fiber iron B vitamins Must be enriched Examples White flour based products Types of Cereal Grains w Wheat most abundantly produced grain 1 75 into flour 25 into cracked wheat bulgur farina wheat germ wheat bran page 350 a Rice varieties differ in their degree of milling and polishing page 351 w CornMaize includes hominy cornmeal masa cornstarch and corn syrup pages 352353 w Oats forms differ in degree of milling cut and precooking page 354 w Millet Sorghum Rye etc Warning to Individuals with Gluten Sensitivity or CD Grains to Avoid Wheat Rye Barley and Foods containing these grains Grains to substitute in prepared foods Corn rice peanut soy arrowroot potato oats etc Caution some oat flours and oat products are contaminated with wheat rye or barley Read the labels Overview of Barley Used primarily in the malt form of flavorings color additives and in the manufacture of beer or whiskey Secondary Uses soups and cereals livestock feed Processing Barley Pearling process by which the hull bran germ andor part of the endosperm are removed Sprouting process of gently drying barley to stop germination and keep enzymes responsible for converting starches to sugars such as maltose The Importance of Malt in the Food Industry yeast ethanol amp 002 decrease in pH lt Maltose Yeast FOOD Pearled endosperm is sprouted to prevent growth of roots while leaving enzymes intact The amylase enzymes are important for breaking down starch to sugars such as maltose amp glucose Uses of Malt yeast substrate or food for yeast sweetener imitation coffee additive and to provide caramel color to colas Common foods to which malt is added include milk shakes cereals waffles pancakes ice cream baked foods cookies crackers pretzels pizza bagels imitation coffees and confections Function of CHO in Foods Sweetness Color Moisture absorption Texture and Thickening Heat Starch Gelatinization Gelatinization cooking of starch granules causing water absorption along with swelling and softening of granules Examples of starch gelatinization ln sauces or gravies resulting in adding starch like a flour and water slurry or cornstarch slurry or a flour and butter mixture The starch will start to swell absorb the water and thicken it In cakes or breads resulting in batters and doughs absorbing the water and are baked in the gel form contributes to the textural development and structure of the baked good Preparation of Cereal Grains Starch stored in packets within the endosperm called granules Each granule differs in gelatinization properties depending on starch source Potato Granule Large vs Corn Granule Small Cooking is dependent upon Grain its respective granule size degree of preprocessing Presence of bran or hu Temperature and cook time pH of cooking water the more acidic the pH the less starch is broken down and the slower the gelatinization will take place Alkaline Conditions faster Gelatinization Pasta Basics Made from flour starch and water that is extruded Extrusion process of shaping and drying pasta dough by forcing dough through formed plates Shapes pasta Dough that is not extruded must be rolled and cut Most pasta is made from semolina a flour derived from durum wheat Whole Wheat Pasta incorporates bran andor germ into dough prior to extrusion Firmer texture stronger taste Usually takes longer to cook yet processing has decreased cook time Al dente to the tooth in Italian Optimum degree of doneness where pasta is tender yet firm enough to offer some resistance to the teeth Chapter 16 Review Questions 00 000quot 3 00693 L 00551 4 Most of the vitamin E in grains is found in what portion of the kernel Husk Germ Endosperm Bran The endosperm of grains is primarily made up of starch protein lipid vitamins Which type of wheat is typically used to make the Lebanese dish called tabouleh Rolled wheat Whole wheat berries Bulgur wheat Fanna Refined grains have four vitamins and one mineral added back to them after processing What is the name for this process QOC39QJ O l QOC39QJ O l 000quot appm Rolling Fortification Enrichment Regulating After wheat the second most common grain used in bread making is corn cornmeal oats rye sorghum Malt is made from germinated sprouted so it serves as a source of gluten wheat oat rye barley What is the best wheat for producing cake flour Soft Hard Red White Chapter 17 The Basic Food Ingredients for Baked Product or Baked Good Flour Leavening Sugar Fat Liquid eggs milk water etc FIavorAdditives salt extracts nuts etc 991990 Yeast bread Bread made with yeast which produces carbon dioxide gas through the process of fermentation causing the bread to rise Quick bread Bread leavened with air steam andor carbon dioxide from baking soda or baking powder Milling of Flour 1 Kernels cracked by rollers 2 Bran and germ removed via sifting and separation 3 Remaining endosperm is ground into flour Stream A division of milled flour based on particle size Patent flour Flour containing the finest streams produced during milling Straight flour Flour containing all the different types of streams produced during milling Functions of FLOUR Flour provides structure to baked goods Via starch and protein contained Within Starch responsible for absorbing moisture during baking and providing structure to nal product Ge lati n ization disruption of starch s molecular structure Which allows starch to absorb water in the presence of heat Function of Flour PROTEINS 0 Proteins glutenin amp gliadin responsible for forming tough rubbery network of water held in coiled proteins o This network is also known as Gluten What is the purpose of gluten formation Plastic and elastic giving RISE to breads enabling the dough to retain trapped gases Provides structure responsible for volume and textural characteristics of baked goods w Glutenin w a a Glutenin Gliadin water Gluten Water Gliadin NW Gluten Crumb The texture of a baked product s interior Gluten The protein portion of wheat our with the elastic characteristics necessary for the structure of most baked products Knead To work dough into an elastic mass by pushing stretching and folding it Wheat Flour Proteins Gliadin and Glutenin Dough Forming 85 Gluten Non Gluten Non dough forming Function of NonGluten Products Contribute to overall sensory properties of product but NOT textural properties Gluten Formation Flour without moisture No Gluten Two Steps of Gluten Formation o Hydration of proteins 0 Manipulation of proteins in the form of kneading Why kneading is important It allows for the formation of disul de bonds between the gluten strands during compression and stretching These are strong bonds that trap C02 and leavening gases Understanding Gluten The higher a our s protein content the greater the our s gluten forming potential Keys to Controlling Gluten 0 Type of our content of glutenin and gliadin proteins 0 Amount of water 0 Amount and dispersion of fat 0 Mixing or manipulation of doughbatter Acidic ingredients How does fat affect gluten formation Fat coats the our particles excluding water from coming into contact with proteins How does acid affect gluten formation Acid interferes with the disul de bonds thereby decreasing gluten formation Strong Gluten Network Made from hard wheat Has hi gh protein content Examples bagels yeast breads puff pastry strudel popovers Weak Gluten Network Made from soft wheat Has low protein content Examples quick breads cakes muf ns pancakes pies Flour Extras Refrigeration extends shelf life but may absorb odors and moisture Whole Wheat Flour Contains bran germ and endosperm Self rising our Has salt and leaveners already added Not a substitute for all purpose our Composite blend of wheat and non wheat These ours have different avor attributes and they also will contribute different textual properties because non wheat ours do not have a percentage of glutenin and gliadin Non Gluten Flours Potato Rice Oat Buckwheat and Peanut Nutrition of Flour High in carbohydrates low in fat low in protein Meaning of Enriched Thiamin ribo avin niacin folate and iron have been added Aging and Bleaching of Flour After milling our is allowed to quotrestquot and air oxidizes the our resulting in whiter our with stronger gluten forming proteins What chemicals are used to speed up aging of our Potassium bromate carcinogen and Chlorine dioxide Leavening Agents Ingredients which cause a dough or batter to rise Three types of leavening agents Physical air and steam Chemical baking powder and baking soda Biological yeast and bacteria Steam heating of water causing an increasing expansion of the dough How is air incorporated into our mixtures Beating the butter adding the sugar and continuing to beat it This is primary one way of incorporating air into a dough or batter Quick Breads Leavened with air steam andor C02 Sweet or savory Swift minimum mixing results in little gluten formation Yeast Breads Leavened by yeast respiration which produces C02 through fermentation Sweet or savory Role of Fermentation Fermentation Process Process in which hydrated yeast cells feed on starches and sugars converting them to ethanol and C02 Produces gasses which become trapped in gluten network of dough causing expansion Yeast CHO C2H50H ethanol C02 carbon dioxide Baking Soda Alkaline compound consisting of sodium bicarbonate ph about 9 Release C02 in presence of an acid food acid and moisture Once incorporated the recipe should be baked immediately bc of the release of carbon dioxide only occurs only one time You want to mix the ingredients just until incorporated and quickly get into the oven so that the gluten network can begin to form and solidify around the gases that are about to be released Baked immediately Commonly Used Acids Buttermilk Sour cream Lemon juice Honey molasses fruits and Cream of Tartar Baking Powder Complete leavening agent contains both acid and alkali When a liquid is added to baking powder the acid reacts with the alkaline baking soda to release carbon dioxide gas The type of acid determines the speed with which carbon dioxide is produced Fast or singleacting powder is available only to commercial bakers A flour mixture made with fast or singleacting baking powder should be handled quickly and efficiently and placed in the oven as soon as possible because it starts to produce carbon dioxide as soon as water is added Any delay allows carbon dioxide to escape and decreases the ability of the mixture to rise Commercial baking powder is doubleacting which means release of C02 initially upon mixing and again upon heating ls actually baking soda acid like cream of tartar Role of Leavening To release air and gases which creates rise and increased volume in final product Leavening by air Initially important Forms pockets in batter Contributes 10 of volume Leavening by steam Produced from water evaporation Contributes 40 of volume Leavening by Carbon Dioxide C02 From reaction of acids and bases or fermentation of yeast Contributes 50 of volume Role of Chemical Leaveners Release C02 through reactions between acids and bases in the presence of a liquid C02 is trapped in pocket within doughbatter and heat causes gases to expand and product rises as starches gelatinize and gluten complexes solidify around the trapped gasses Sugar Types of Sugar Granulated Brown Tu rbinado Honey Powdered NectarsSyru ps Function of Sugar Increases volume of baked goods Increases temperature of gelatinization above 165 F Food for yeast Contributes moistness and tenderness Aids in browning reactions caramelization How does sugar increase volume As a food for yeast that are involved in fermentation reactions Contribute to volume increases due to beating of fat and sugar particles together Those sugar particles create tunnel pockets throughout the beaten butter that allows for air to be incorporated and entrapped within Why is higher temperature of gelatinization important At higher temperatures the more sugar that is present gelatinization will take place at higher temperatures This allows for a longer amount of time for gluten to develop Fat Types of Fat Butter Crisco Oil Lard Baking Grease Coconut Oil Function of Fat in baked goods Flavor enhancer Increased volume and strength Adds richness and moisture Tenderization via shortening gluten strands important in yeast bread Extension of shelf life by delaying staling How does fat increase volume When fat melts it leaves air pockets that can trap C02 How do sugars differ Plant Source Amount of Moisture Size of Particles Liquids Types of Liquids in baked goods Milk Water Eggs Honey Juices Syrup Function of Liquids in baked goods Flavor enhancer via fat and sugar components except water or eggs Tenderization of gluten in presence of fat and sugar Protein adds structure Dispersing agent Retrogradation of Baked Products Seepage of water out of aging gel as a result of amylose reassociation Also known as weeping Causes staling of product which can be visible or invisible Example puddings sauces pies and stale bread You are tasting the loss of moisture Salt Types of Salt lodized Kosher Cracked Sea Flakes Seasoned Functions of Salt in baked goods Flavor Strengthens gluten network Modified yeast activity Preservative How does salt strengthen gluten network By iodizing protein molecules and iodizing glutenin and gliadin which allows them to better align bind and form network to entraps water How does salt modify yeast activity By slowing yeast activity to allow for slow metabolism of carbohydrates to produce C02 Without salt C02 production would be too rapid Tougheners Proteinrich ingredients that provide structure and strength to final product Examples Flour Milk Eggs Tenderizers Ingredients that interfere with gluten formation making cake soft and tender Examples Sugar Egg Yolks Fat Moisteners Necessary for gluten formation and starch gelatinization Examples Water Milk Cream Eggs Drying Agents Ingredients that absorb moisture giving body and structure to cake Example Flour Leavening Agents Contribute rise and body to cakes via gases and air Examples Baking Soda Baking Powder Yeast Flavorings Provided desired flavors Example Salt Extracts Chocolate Nuts Fate of Gases in Baking Process Trapped by gluten network giving rise to product Fate of Starches in Baking Process Hydrate gelatinize and stale retrogradation Fate of Proteins in Baking Process Coagulate in gluten network providing texture and structure Fate of Fats in Baking Process Melt to form pockets where gases collect and expand Fate of Water in Baking Process Evaporates forming steam that is trapped within gluten network Fate of Sugars in Baking Process Caramelize on exterior of product bind water and aid in moisture retention during shelf life Proof To increase the volume of shaped dough through continued fermentation Is it a Batter or Dough Batter High water content Minimal gluten formation Soft tender products Texture pour pancakes popovers shortened cakes some cookies and waf es drop cream puffs muf ns quick bread some coffee cakes and some cookies Dough Low water content Tough water protein complex gluten Usually stiff enough to cut Texture soft biscuits rolls scones some cookies and yeast dough stiff and rm pasta pastry pie dough and some cookies Chapter 19 Quick Breads Liquid Flour Batter or Dough Depends on ratio of liquid to flour batter or dough Batter more pourable Dough more viscus less pourable more drop and manipulation need By nature quick breads are tender products with a soft crumb Very little gluten is formed in quick breads due to swift minimum mixing Recipes often state mix just until incorporated to prevent extra gluten formation Three methods of mixing Muf n BiscuitPastry Creaming Muf n Method of Mixing Dry ingredients mixed and sifted together Liquid ingredients combined together Liquid ingredients added to dry well Blended just enough to wet dry ingredients lumpy batter Over mixing will cause toughness GOAL tender product with even shape and distribution of ingredients Biscuit Method of Mixing Cut solid fat into dry ingredients Liquid ingredients added in small quantities until dough clings together Roll out or knead according to directions Fat layers melt creating pockets to trap steam It separates the gluten sheets creating akiness rather than toughness GOAL light aky tender product Creaming Method of Mixing Sift dry ingredients Cream fat to form air pockets Add sugar to assist in aerating butter or shortening Add eggs one at a time Alternate adding liquid and dry ingredients beginning and ending With dry GOAL ne textured product With uniform consistency no tunnels Used for conventional cakes Primary differences in Mixing Methods The type and manipulation of fat Muf n fat melted if solid and added to liquid ingredients Biscuit cut into dry ingredients Creaming Whipped until uffy Chapter 18 Complex Carbohydrates Polysaccharides are not sweet not H20 soluble Starch Digestible Polysaccharides Derived from plant sources such as corn potato rice and wheat Starch broken down and used for energy Exists as granules of gt200 glucose molecules having both branched and unbranched structural regions Branched Regions Amylopectin Unbranched Regions Amylose Composition of Amylose Starch Amylose long chains of glucose molecules Amylose starch absorbs water easily Thicken and swell when heated with water example cornstarch Yields dry fluffy mouthfeel as in baked white potatoes Composition of Amylopectin Starch Amylopectin shorter branched chains of glucose Amylopectin starch does not hydrate well due to bulkiness of structure Yields waxy texture as in boiled red potatoes Dextrose equivalent DE A measurement of dextrose concentration A DE of 50 means the syrup contains 50 dextrose Dextrinization Upon exposure to extreme heat starch granules begin to breakdown Breakdown of amylose and amylopectin molecules results in shorter sweeter chains of glucose Food Examples rue sweet taste cooked to a dark brown of preparing gumbo Toasted bread wheat bread toasted cereal grains Glucose derived from starch is called dextrose DE dextrose equivalents Starch Gelatinization Heating starch granules opens the granule allowing for water absorption Result swelling and softening of granules Food Examples cooked grains pasta rice and oats Factors Influencing Gelatinization TEMP Starches do not dissolve in cold or roomtemperature water Stirring facilitate heat transfer Acidity decreases starches to thicken Sugar absorbs the water and competes with the starch to absorb the water Starch will take longer to hydrate due to the amount of sugar in solution Gel Formation Upon cooling some gelatinized starches will convert into a semisolid paste or gel Dependent on the presence of amylose in the starch How does amylose contribute to gel formation amylose is the component of starch which binds with water and forms the gel Food Examples stir fry sauces puddings and pie formations Retrogradation Definition The seepage of water out of an aging gel because of the contraction of the gel bonds tighten between the amylose molecules Retrogradation is also known as syneresis or weeping Retrogradation in Foods pudding pies stir fry sauces Chinese sauces or any starch thickened product that is formed to gel that is not going to be reheated before cooking Sauces Modified starch A starch that has been chemically or physically modified to create unique functional characteristics Stock or Sauce What s the Difference Stock strained liquid made from cooking bones vegetables and seasonings in water Most soups begin with a stock Many sauces are based on reduced stocks Sauces liquid plus seasonings plus thickening agent o What type of liquid White stock from chicken veal or fish velout Brown stock from beef or veal espagnole Milk b chamel Clarified butter hollandaise Tomato juice or pur e tomato sauce Accompany foods to add flavor moisture richness etc Gravy type of sauce made from meat juices stock and thickening agent Basics of a Sauce Liquid White stock from chicken veal or fish velout Brown stock from beef or veal espagnole Milk b chamel Clarified butter hollandaise Tomato juice or pur e tomato sauce Thickener add a starch thickener in the form of either a roux roo beurre mani burr mahnyay or slurry Seasonings salt black pepper white pepper lemon juice cayenne herbs and wine Mother or Leading Sauces gt B chamel made by thickening scalded milk with white roux gt Easiest to make most versatile gt 5 Ways with B chamel Butter flour milk salt and pepper gt Velout made by thickening a white stock or fish stock with roux gt Espagnole aka made with brown stock with brown roux gt Very rich and heavy in texture gt Tomato made from tomatoes vegetables seasonings white stock and blond brown roux gtMost commonly used sauce Mother sauce A sauce that serves as the springboard from which other sauces are prepared Small sauce A secondary sauce created when a flavor is added to a mother sauce Glaze A flavoring obtained from soup stock that has been concentrated by evaporation until it attains a syrupy consistency with a highly concentrated flavor Roux A thickener made by cooking equal parts of flour and fat Mother or Leading Sauces gt Hollandaise emulsified sauce of egg yolks butter small amount of water and lemon juice or vinegar gt Buttery rich and slightly tangy gtPaired well with fish asparagus broccoli and cauliflower gt Emulsion process by which immiscible liquids like oil and water are forced into a uniformly dispersed state gt The stability of emulsions relies on an emulsifier or stabilizer gtCommon food emulsions oil and water StarchBased Thickening Agents Roux equal parts flour and fat cooked for use as a thickening agent Principle means of thickening sauces Cooked together for varying lengths of time to develop color aroma flavor Function of fat is to coat the flour and prevent it from lumping when added to hot liquid Function of the starch flour As the roux cooks it becomes darker and its starchy taste lessens but its ability to thicken is also reduced as the starch molecules are broken down by heat Thus the darker the roux the more of it will be needed to add to the liquid for thickening purposes Roux is whisked into a liquid and then cooked approximately 20 min to allow for thickening and removal of raw flour taste Types of Roux White blond and brown Variations in the heating times of the fat flour combination cause the differences in the colors and flavors with the most cooking producing the brown roux Thickening Agents Cornstarch inexpensive starch used to thicken liquids through gelatinization Must be mixed with cold water to create a slurry before adding to hotwarm liquid Greater thickening power than flour Requires less cooking to remove raw taste z5 min Beurre Mani butter and flour mixture used for quick thickening at the end of cooking Differs from a roux because it is not cooked together before adding to a sauce Flour thickens via gelatinization Slurry A thickener made by combining starch and a cool liquid Finishing Techniques for Sauces Reduction process of heating a liquid until its quantity decreases via evaporation Commonly used to thicken a sauce without relying on the addition of starches such as cornstarch Straining removes any lumps created by the unequal wetting of starch granules Aids in creating consistently smooth texture Au jus Served with its own natural juices a term usually used in reference to roasts Deglaze To add liquid to pan drippings and simmerstir to dissolve and loosen cooked on particles sticking to the bottom of the pan Chapter 18 Review Questions 1 Amylose has a structure whereas amylopectin is a branched smooth b linear branched c branched linear d linear smooth 2 What is the word used to describe the breakdown of starch molecules to smaller sweetertasting dextrin molecules in the presence of dry heat Gelatinization Dextrinization Retrogradation Deglazing Q0 03951 00 Starches that have been altered to affect their heating times viscosity or gelatinization are referred to as gelled starches smooth starches tough starches modified starches QOC39Q A A roux is a thickener made by cooking equal parts flour and fat water stock starch QOC39Q O l What two ingredients are combined to make a slurry flour hot water flour starch starch cool liquid cool liquid hot liquid 00551 03 The increase in volume viscosity and translucency of starch granules heated in a liquid is referred to as gelatinization dextrinization retrogradation deglazing 000quot l The seepage of water out of an aging gel because of the contraction of the gel is called gelatinization dextrinization retrogradation deglazing QOC39Q Chapter 20 What is yeast Unicellular fungi Growth of yeast Once hydrated in 105 F to 110 F water yeast cells feed on starches and sugars converting them to ethanol and 002 Temperature affects on yeast Above 140 F all yeast are destroyed Below 50 F yeast activity is slowed Optimum growth temperature is 68 F100 F Fermentation Process in which hydrated yeast cells feed on starches and sugars converting them to ethanol and 002 Produces gasses which become trapped in gluten network of dough causing expansion Yeast 0H0 02H50H ethanol 002 carbon dioxide Essential ingredients in yeast breads Flour Water Yeast Salt Lean Dough yeast breads Include essential ingredients plus herbs Examples french bread sourdough rye bagels pretzels english muffins pita Rich Dough yeast breads Include essential ingredients plus sugar fat andor eggs Examples Brioche and 0hallah Why is salt essential to yeast bread Strengthens gluten and makes it more elastic Why is this important Slows fermentation reaction Too much salt Dramatically inhibits yeast activity Dough will not rise Too little salt Dough will rise too much Role of added ingredients in Rich Yeast Dough Role of Sugar in rich yeast dough Energy source for yeast However cannot exceed 10 of dough Slows production of 002 by yeast Role of Fat in rich yeast dough Tenderizes and prevents staling Role of Egg in rich yeast dough Contributes moisture and acts as emulsifier Increases volume Prevents staling by retaining moisture Production Stages for Yeast Breads Measure ingredients Mix and knead dough Ferment and punch down dough Portioning rounding and shaping dough Proofing Baking Proofing To increase the volume of shaped dough through continued fermentation Final rise of yeast products prior to baking Requires higher temps than fermentation with higher humidity to prevent drying Mise en Place French phrase for everything in place Accurate measurements are essential Roomtemp ingredients incorporate easier Use the recipe as a guide Why do recipes call for a range of flour This is best when you start at the lowest and gradually add more flour as needed to form a cohesive non tacky spongy dough This is the ultimate goal Amount of flour varies based on humidity storage accurate measurements Four with higher protein will absorb more liquid Kneading of Yeast Breads Essential pressing and folding step responsible for combining ingredients uniformly distributing yeast and developing gluten Helps proteins hydrate develops gluten and warms dough to temperature conducive for yeast activity Goal moderately smooth elastic dough Fermentation Process in which hydrated yeast cells feet on starches and sugars converting them to ethanol and 002 Changes during Fermentation 002 is trapped causing dough to rise Increased acidity of dough due to formation of carbonic acid 002 mixing with water and formation of lactic acid and acetic acid by yeast Alcohol is produced but will evaporate upon baking Length of Fermentation Determinants of rising time for yeast breads length of fermentation Type and amount of yeast Amount of sugars and food sources for yeast Temperature Salt concentration Mixing method Fermentation of Yeast Breads 0 After kneading dough may be covered with oil and cloth or plastic wrap then allowed to stand in warm moist place75 to 85 F 0 Fermentation is complete when dough doubles in size and no longer springs back when pressed with two ngers Dough may be punched down and allowed to rise again depending on the recipe 0 Punching Down the Dough encourages more yeast activity and it allows it to go through another rise or another opportunity to trap C02 and expand the gluten network Proo ng of Yeast Breads Proo ng 0 Final rise of yeast products prior to baking 0 Requires higher temperature than fermentation 80 to 115 F with higher humidity to prevent drying and crust formation 0 Why is it important to prevent crust from forming The crust will prevent the gluten from expanding even further and will form a semi solid barrier and limit the full textural development of the gluten in its entirety It will minimize the nal texture of the yeast bread be less in height than it truly should have been 0 GOAL dough doubles in size and springs back when lightly touched Under proo ng proof our dough and forget about it Can contribute to poor volume and texture Over proo ng over abundant activity of the yeast which produces a sour avor and pale color because they have metabolized all of the sugars Therefore there will be nothing for caramelization on the exterior of the crust It will also contribute to a poor volume The Baking Process 0 During the rst 10 to 15 minutes dough experiences a quick rise termed oven spring 0 Oven Spring is the term for this rise resulting from the production and expansion of trapped gases 0 As dough temperature increases 0 Yeast dies 0 Gluten rms Starches gelatinize 0 Moisture evaporates Crust forms and browns 0 To enhance appearance dough may be washed or scored before baking The Baking Process Baking amp Indicators of Doneness 0 Volume 0 Tapping the bottom listening for a hollow sound 0 Texture and color of the crust Instant read thermometer internal temp of 190 210 F Cooling 0 Cool on wire racks at room temperature away from drafts 0 Remove from pans rolls etc unless otherwise indicated 0 Cool completely before slicing with a serrated knife 0 Do not refrigerate why It speeds the staling Chapter 21 Nonnutritive sweeteners Food additives requiring FDA approval that provide sweetness with no or insigni cant amounts of energy calorieskcal Also known as alternative sweeteners sugar substitutes sugar replacers and macronutrient substitutes Sugars Sugar is what usually comes to mind when the word sweetener is used Once it has been extracted from its plant source sugar becomes a re ned carbohydrate providing a pleasing avor and packing 4 calories kcal per gram Sugar s ability to sweeten makes it the number one food additive by weight in the United States Function of Sugar in Foods Sweetness Increase Volume Crystallization Browning Caramelization Hygroscopic Texture Fermentation Preservation Leavening Increase shelf life Why does brown sugar dry out and become hard Drying and hardening occur because even though the molasses lm over the sugar keeps brown sugar soft and pliable at rst but it hardens as soon as the water from the molasses evaporates Hard sugar can be softened by draping a moist paper towel over the sugar within its container for about 12 hours sugar draws the moisture to itself Brown sugar can also be temporarily softened by brie y heating it in an oven at 250 F 3OO F 121 C 149 C or in a microwave Place a piece of bread in the container sugar will absorb water Store in airtight container or store in plastic bag in refrigerator Syrups Syrups are sugary solutions that vary Widely in viscosity carbohydrate concentration avor and price The more common ones include corn syrup highfructose corn syrup honey molasses maple syrup and invert sugar Dextrose equivalent DE A measurement of dextrose concentration A DE of 50 means the syrup contains 50 dextrose Highconversion corn syrups Corn syrups with a dextrose equivalent over 58 What changes are required When substituting honey for sugar 1 Use one part honey for every 1 14 parts sugar Reason honey has a slightly higher percentage of fructose than sugar it tastes sweeter and this will affect the final flavor of the product 2 Reduce the liquid in the recipe by 14 cup Reason honey is largely water so less liquid is needed 3 Add 12 teaspoon baking soda for every cup of honey Reason baking soda reduces the acidity and offsets the weight of honey to allow the cake to rise Crystallization The precipitation of crystals from a solution into a solid geometric network Invert sugar An equal mixture of glucose and fructose created by hydrolyzing sucrose Sugar Alcohols Foods containing sugar alcohols can be labeled sugar free because they are low in calories Sugar alcohols are not carbohydrates but the alcohol counterparts of speci c carbohydrates Although they are found naturally in fruits and vegetables they are also synthesized by hydrogenating certain sugars Sugar alcohols are also referred to as polyols polyalcohols and polyhydric alcohols Humectant A substance that attracts water to itself If added to food it increases the water holding capacity of the food and helps to prevent it from drying out by lowering the water activity Acceptable Daily Intake ADI The amount of a food additive that can be safely ingested daily over a person s lifetime Five Approved NonNutritive Sweeteners Saccharin Sweet 39n Low Aspartame NutraSweet AcesulfameK Sunette Sucralose Splenda Stevia Truvia Drawbacks of using nonnutritive sweeteners in baking One drawback of nonnutritive sweeteners is that they lack the important functional characteristics of sugar bulking binding texturing and fermenting However certain compounds can be added to foods to compensate for the lost characteristic of bulking These include cellulose maltodextrin also used for its binding property the sugar alcohols and polydextrose Polydextrose provides a texture similar to sugar with only 1 calorie kcal per gram and is currently approved for use in frozen dairy desserts baked goods and mixes confections and frostings hard and soft candy chewing gum gelatins puddings and fillings and salad dressings Noobservedeffect level NOEL The level or close at which an additive is fed to laboratory animals without any negative side effects Reducing sugars Sugars such as glucose fructose maltose and others that have a reactive aldehyde or ketone group Sucrose is not a reducing sugar Caramelization A process in which dry sugar or a sugar solution with most of its water evaporated is heated until it melts into a clear viscous liquid and as heating continues turns into a smooth brown mixture Hygroscopic The ability to attract and retain moisture When making a shortened cake can powdered sugar be substituted satisfactorily for granulated sugar on a weight basis On a measured basis Weight Basis Confectioners powdered sugar cannot be substituted satisfactorily for granulated sugar on a weight basis because the light airy nature of confectioners sugar causes it to have a greater volume than the same amount of granulated sugar which is why 1 34 cups of confectioners sugar is equal to the weight of 1 cup of granulated sugar Measured Basis Confectioners powdered sugar can be substituted satisfactorily on a measured but it must be sifted before measuring to break up any existing lumps After sifting confectioners sugar is measured the same way as granulated sugar Chapter 23 Shortened cake butter or conventional cakes A cake made with fat Leavened with baking powder or soda Examples Pound Cake Fruit Cake Chocolate Cake Yellow Cake White Cake and Spice Cake Unshortened cake sponge or foam cakes A cake made without added fat Leavened with beaten egg whites Examples Angel and Sponge Chiffon cake hybrid of shortened and unshortened A cake made by combining the characteristics found in both shortened and unshortened cakes Leavened with both baking powder or soda and beaten egg whites Chocolate Chiffon and Lemon Chiffon Function of Sugar in cake preparation include 1 sweetening 2 increasing volume 3 browning the crust and 4 increasing shelf life Why use powdered sugar rather than granulated sugar in uncooked frosting Powered sugar dissolved instantly in unheated liquids Also need to add a fat to prevent frosting from being dry and cracking Why are cookies crispier than cakes The sugar starch and our proteins all compete for the small amount of liquid available There is very little starch gelatinization or gluten formation Gluten development is also hindered by the high fat content Slide 1 Food Science is an applied discipline meaning we take from many different sciences and incorporate those into the understanding of the functionality of food The science is involved in creating the food products that we are accessible to today Slide 2 Lipids aka Fats Energyyielding nutrients Carbohydrates Protein Lipids Macronutrients non energyyielding nutrients Water Vitamins Minerals Micronutrients Slide 3 Food Science pre digestion vs Nutrition post nutrition Complexity of food ingredients example cheese Slide 4 Food science is an applied science Chemistry is the mother science behind food science Slide 5 Processed foods have a greater amount of one nutrient or the other than the food in the fresh state ex sugar Slide 6 How does chemical structure influences flavor texture color and preparation method The chemical structure is important to interaction between nutrients it matters because if the compound and molecule are too large it will not be perceived by our taste buds Smaller molecules are taken in on the tongue and we perceive them as sweet salty and bitter Larger molecules are not ex carbohydrates We don t taste fiber perceive glucose as being sweet Slide 7 Two Forms of Water in Food Free water and Bound water Both of these influence sheHHve Free Water the largest amount of water present in foods is easily separated from the food Bound Water incorporated into the chemical structure of other nutrients such as carbohydrates fats and proteins Examples would be the free water found in fruit and the bound water found in bread Bound water is not easily removed and is resistant to freezing or drying It also is not readily available to act as a medium for dissolving salts acids or sugars Slide 8 Liquid ingredients have water ingredients as well as dry ingredients Dry ingredients still have degree of water activity ex chicken noodle soup Slide 9 Solvent substance usually a liquid in which another substance is dissolved Water Solute Solid liquid or gas compound dissolved in another substance Hot Chocolate Solubility ability of a substance to blend uniformly with another Water and HC Slide 10 Solution completely homogenous mixture of a solute dissolved in a solvent For example Hot chocolate sugar and water as well as salt and water Suspension mixture in which particles too large to go into solution remain suspended in the solvent Starch and water slurry that we use to thicken soups and gravies Emulsion mixture of two immiscible liquids Ex salad dressing and mayo lava lamp Slide 11 Water Activity the less water that remains in a food the longer the food shelf life Aw of pure water 100 Slide 12 Tomato highest water content oil lowest water content Slide 13 Vitamins Organic compounds They contain carbon destroyed very readily during the cooking process and easily destroyed by heat oxygen and exposure to light Fatsoluble A D E and K Water Soluble B complex and vitamin C Minerals inorganic elements that provide no calories but perform a functional role in numerous metabolic processes They are not destroyed by the cooking process Examples iron zinc magnesium sodium calcium chloride potassium Slide 14 Enriched adding nutrients back that were present in their original state that were lost during production Examples thiamin riboflavin niacin iron and folic acid Fortified adding nutrients to a food that were not present in its original state Example adding of calcium to orange juice Slide 15 Most common food additives salt sugar corn syrup Each of these add flavor and enhance the properties of their food but primarily for their preservation abilities Slide 16 Food Additives What The Purpose The FDA is the oversight agency for approving and regulating food additives 1 Improve the appeal of foods by improving their flavor smell texture or color 2 Extend storage life 3 Maximize performance 4 Protect nutrient value Slide 17 Goal of Food Science Preserve and produce food products with maximum retention of nutrients in quantities similar or exceeding the amount of those in natural state Slide 21 Carbohydrates CHO sugars starches and fibers found in food Plants are the primary source of CHO Exceptions milk and diary products contain lactose contains sweetness Stored in the seeds roots stems and fruit of plants CHO carbon C hydrate H20 gt CnH20n N indicates the number of carbons the number of water molecules in this carbohydrate molecule Carbohydrates are classified by the of saccharide units Monosaccharides one saccharide unit or one CnH20n Disaccharides two monosaccharide units Oligosaccharides 310 monosaccharide units not as common in foods Polysaccharides gt 10 monosaccharide units Slide 22 Focus on Glucose Fructose Galactose Monosaccharides Disaccharides Sucrose Maltose Lactose Polysaccharide Digestible Plant Starch Amylose Amylopectin Animal Starch Glycogen Undigestible Fiber Cellulose Hemicellulose Pectin Gums lnulin Slide 23 Monosaccharides simplest sugars sweet to the taste 6 carbon chain Most predominant monosaccharides Glucose most common simple sugar found in foods also found in the blood which allows us to access insulin sensitivity and diabetic responses Fructose also known as fruit sugar sweetest of all naturally occurring sugars Galactose component of milk sugar Slide 24 Disaccharides Sucrose table sugar is composed of 1 glucose molecule and 1 fructose molecule Maltose is composed of 2 glucose molecules linked together Uses of maltose breakfast cereals and the production of beers Lactose milk sugar is composed of 1 glucose molecule and 1 galactose molecule Source diary products Lactose intolerant individuals lack the enzyme necessary to breakdown lactose Slide 25 Why the industry use high fructose instead of regular fructose is that the breakdown in composition of high fructose corn syrup which is 40 o50 o fructose and approximately 40 o50 o glucose vs pure fructose is because fructose by itself is heavy sticky and it does not behave well in food systems doesn t intersperse well other ingredients browns very readily and produce smooth texture Slide 26 Complex Carbohydrates Polysaccharides are not sweet and most are not H20soluble Contain numerous monosaccharide units linked together gt10 These are very large molecules Most common food polysaccharides can be grouped into two main categories Digestible Polysaccharides starch and glycogen lndigestible Polysaccharides fiber in its various plant forms Slide 27 Starch vs Fiber Starch Digestible polysaccharide from plant sources Derived from photosynthesis reactions in which radiant energy is covered into glucose and stored within the plant as starch Fiber lndigestible polysaccharide from plant sources NFP requires the listing of both soluble and insoluble fiber Soluble Fiber can dissolve in water Examples would be dried beans and grains oats rice barley Insoluble Fiber cannot dissolve in water Wheat bran and rye Slide 28 Vegetable Gums Thickening by binding H20 emulsifying stabilization Most commonly used in ice creams jams confectionary products salad dressings etc Slide 29 Function of CHO in Foods understand this slide Contribute to sweetness color the reactions known as browning and caramelizing active in absorbing moisture enhance the texture and thickening embark flavor sweetness and enhancement of other flavors and take part on the reactions of fermentation Slide 30 Food Lipids Lipids are comprised of two basic groups Fats come animal sources more saturated in nature tend to be solid at room temperature due to the fact that they contain a high percentage of saturated fats Oils plant origin more unsaturated in nature giving them the fluidity of room temperature Lipids are insoluble in water Oils and water don t mix Most common form of edible lipids triglycerides Triglyceride glycerol backbone and 3 fatty acids Those fatty acids are very unique because they either can be the same or 3 different fatty acids bound to a glycerol backbone Slide 31 Fatty Acids Fatty Acids FA are composed of carbon chains categorized as either saturated or unsaturated Saturated FA Structure when all C s within the FA chain are bound to two C s and two H s all bond points of C are FULL Unsaturated FA Structure when one or more double bonds between C s are present due to an absence of H atoms within the chain Trans FA unsaturated structure due to presence of DB s but body treats trans fats as saturated Highly controversial for health yet very stable cheap fat often used in the industry Increased consumer scrutiny has forced many food reformulations Slide 32 Saturation Review Saturated Lipids Primarily Animal Sources Meat Poultry MilkButterCheese Egg Yolk Lard no double bonds Plant Sources Chocolate CoconutCoconut Oil Palm Oil Vegetable Shortening Monounsaturated Sources Avocado PeanutsPeanut Butter OlivesOlive Oil One double bond Polyunsaturated Primarily Plant Sources Vegetable Oils Corn Safflower Soybean Sunflower Canola etc Margarine most Mayonnaise Certain Nuts Almonds Filberts Pecans Walnuts Animals Sources Fish two or more double bonds Slide 33 Importance of Saturated and Unsaturated Fats to F8 Importance in Food Science Lipids with greater of double bonds of higher degree of unsaturation are more easily oxidized than saturated fats Have a shorter shelf life Importance in Nutrition Lipids with greater of double bonds or higher degree of unsaturation adhere less easily to artery walls Less plaque forming Slide 34 Free Radicals unstable molecules that are extremely reactive and can damage healthy cells In foods free radicals can oxidize food ingredients like lipids causing off flavors and decreasing shelflife Slide 35 Antioxidants compounds which inhibit oxidation which would ultimately cause deterioration of food ingredients 1 A chemically reactive oxygen free radical attacks fatty acids forming other free radicals 2 This initiates a rapid destructive chain reaction 3 The result is deterioration of foods containing unsaturated fatty acids Vitamin E stops the chain reaction by changing the nature of the free radical Slide 36 Functions of Lipids in Food To Transfer Heat good conductors in heat Aid in tenderization of foods fat in the food tenderizes the other ingredients Texture amp mouthfeel Flavor and satiety Slide 37 Food Proteins Composed of amino acids joined by peptide bonds Contain Nitrogen Distinguishing feature from other macronutrients of the three macronutrients Important for bones Protein molecules have a 3D shape which can be destroyed in a process known as denaturation Denaturation is important because it tenderizes food proteins and creates new textures via mechanical means the whipping of air into an egg white denatures the 3D structure of that molecule and allows the egg whites to hold air In baking in that form the egg white foam has now created a new texture via chemical means the addition of acids or acids such as to a marinade in which those ingredients are added to a marinade applied to a meat in order to tenderize the proteins denaturing the 3D structure opening up the coiled molecule allowing for flavors and heat to penetrate so that they can be allowed to be less tough and dense Lastly denaturation can occur through physical means which is the application of heat which denatures protein molecules and tenderizes them in doing so Slide 38 Functions of Proteins in Food Hydration great trackers of water and liquids Involved in enzymatic reactions enzymes are by nature proteins Browning different type of browning that involves caramelization which is called a Maillard Browning This involves a reducing a sugar proteins and water in presence of heat Buffering prevent major changes in pH diary lecture cheese making Slide 39 Functions of Proteins in Food Understand what the building blocks of each of the MacroNutrients what the functions are of each of the Macronutrients the distinguishing feature is between each of the 3 categories of Macronutrients Hydration ability of protein molecules to attract and bind water allows proteins to thicken foods form gels etc Enzymes protein molecules which act as catalysts to speed up reac ons Enzymes in Food added to milk in cheese production tenderize meat improves filtration of beer etc Buffering protein molecules aid in resisting extreme pH shifts in food products Browning two basic types of growing reactions one of which involves proteins Enzymatic browning result of an entirely different mechanism than the Maillard reaction It requires the presence of three substances oxygen an enzyme polyphenolase and a phenolic compound Figure 329 Slide 1 Slide 2 Slide 3 Slide 4 Slide 5 How do we keep food safe as a consumer and at the retail level Vulnerability of Our Food Supply Increasing distance from farm to fork Multilevel targets with regard to traceability Point of entry or origin vs point of consumption Overwhelming need for monitoring and regulation FDA USDA EPA CDC Bioterrorism Act of 2002 Prevalence of Foodborne Illness 76 million cases annually in US 325000 hospitalizations annually due to food poisoning 5000 resulting deaths Annual cost of foodborne illnesses ranges from 65 to 349 billion According to 2002 FDACFSAN estimates most common food microorganisms include E Coli and Salmonella Food Contamination Foodborne Illness Any illness resulting from ingestion of contaminated food Three types of hazards associated with foodborne illness Biological Chemical and Physical Biological Hazards Bacteria viruses mold and their toxins parasites Usually transmitted by Preparer Most common cause of illness Chemical Hazards Sanitizers cleaning agents pesticides antibiotics hormones toxic metals lead mercury copper zinc dispersed in food and water etc Physical Hazards Glass wood plastic metal shavings from a can opener hair etc Slide 6 Methods of Contamination Direct contamination of raw foods plants or animals from their natural setting Examples tainted water supply and non potable water in a food processing facility environmental pollutants or just the movement of microorganisms from their indigenous environment around the plant to the plant itself lndirect transmission of contaminants via handling and preparation Crosscontamination by food handlers is the MOST common method of transmitting foodborne illnesses Slide 7 Biological Hazards Slide 8 Bacteria specifically pathogenic bacteria are the leading cause of foodborne iHness Multiply by binary fission Generation time is about 20 minutes for numbers to Double Keep hot foods hot and cold foods cold TimeTemperature Principle make sure you pay attention to the Temperature Danger Zone keep food at the temperature that will prevent microbial growth The USDA recommends 40140 degrees contains the temperature danger zone The range at which bacteria are able to multiply every 20 minutes According to the FDA Food Code for retailers the temperature zone is defined as 41 135 degrees Slide 9 Potentially Hazardous Foods Foods on which microorganisms thrive particularly pathogenic bacteria High protein High H20 content Given the right temperature pH and the presence of other nutritive compounds for growth Examples animal based products and vegetables Low temperature storage is the best line of defense against microbial growth Slide 10 FightBac FAT TOM Food Acidity Time Temperature Oxygen Moisture Food require for microbial growth living organisms that need food Acidity pH 46 and below results as bacteria not being to thrive Highly acidic foods tend to spoil less quickly Time given the right environmental and growth conditions bacteria can double every 20 minutes The longer the food is out the more cells are present in the food Temperature Look at Temperature Danger Zone Oxygen Some microorganisms require oxygen growth while others do not Even though you have sealed the food in the bag and released the air there s a chance that oxygen is present Foods can still be contaminated even though you have released most of the head space in the bag Moisture Slide 11 Foodborne Infection 3 types of illnesses that can cause a biological hazard infection intoxication intoxification Definition illnesses occurring from ingestion and growth of causative bacteria in the intestinal tract The bacteria growing inside you makes you sick Symptom Onset 12h to 2d depending on number of cells ingested Examples Salmonella C Jejuni E Coli Enteroinvasive Slide 12 Food Intoxication Definition illness involving ingestion of toxins produced as byproducts of microbial growth It s the toxin produced by the bacteria growing on the food you ate that makes you sick Symptom Onset within hours of ingestion Examples S Aureus E Coli enterotoxigenic C botulinum Slide 13 Food lntoxification AKA toxinmediated infection Definition illnesses occurring when causative bacteria are ingested grow and produce toxins within the small intestine It s the toxin produced by the bacteria growing inside of you that makes you sick Symptom Onset 29 days Examples C Perfringens E Coli Enterohemorrhagic Slide 14 Chemical Hazards Associated with Foodborne Illness Code of Federal Regulations Title 21 Part 109 Unavoidable Contaminants in Food Part 184 Direct Food Substances Affirmed as GRAS Part 172 Food Additives Permitted for Direct Addition for Human Consumption FDA s Compliance Policy Guidelines provides information on naturally occurring chemicals Slide 15 Chemical Hazards 1 Environmental pollutants pesticide 2 Toxic Metabolites produced by plants 3 Environmental metals iron being incorporated at high levels into a vegetable commodity during its phase in the growing environment 4 Food Allergens Slide 16 Food Allergens as Hazards Naturally occurring proteins in the following foods are associated with an immune response in susceptible individuals MEFSTNPWS Milk Eggs Fish Shellfish Tree Nuts Peanuts Wheat Soy If a food contains any of these compounds or was processed in a facility where also these compounds were processed or in any way could have come in contact with these allergens then it must bare the label Slide 17 Sources of Risk Inadequate cooking lmproper holding temperatures Food from unsafe sources Poor personal hygiene Contaminated equipment Are you serving to a highrisk population Examples include giving a talk conducting business serving those with allergies Slide 18 Reducing Your Risks Handling and Storage Clean hands properly and often Clean wash and sanitize equipment Hold foods at proper temperatures Store raw foods on shelves below prepared foods Pest Management Keep food sealed Clean up spills immediately Enlist aid of pest control methods if required Slide 19 Controlling Risk Factors Look at Table 410 Slide 20 Food Safety Monitoring Hazard Analysis and Critical Control Point HACCP Food safety management system relying on process controls to minimize food safety risks in the food processing industry Seven principles focus on prevention and reduction of food safety risks Slide 21 7 Principles of HACCP Analyze Hazards Look at each step eg purchasing delivery storage preparation cooking chilling etc Identify Critical Control Points CCP Identify the points in your operation that ensures control of the hazards Establish critical limits for each CCP Set limits to enable you to identify when a GOP is out of control eg when cooking beef burgers the centre of the burger must reach a minimum temperature of 75 C or an equivalent time temperature combination eg 70 C for 2 minutes to ensure pathogens are destroyed Establish procedures to monitor CCPs Typically monitoring will involve measuring parameters such as temperature and time Establish corrective actions the temperature of the food in a refrigerator rises to 10 C due to a technical fault Discard the food and repair the refrigerator using the manufacturer s instructions to ensure the correct temperature of 5 C is achieved Establish verification procedures When replacing an oven verify that the timetemperature settings in the new oven achieves the minimum safe cooking temperature for a particular dish by probing thefood Recordkeeping and documentation Chapter 9 CLASSIFICATION OF FISH AND SHELLFISH Vertebrate The vertebrate category includes n sh which obtain their oxygen from the water through their gills and sea mammals all of which must get their oxygen from above the water s surface Finfish Fin sh are found in the fresh water of rivers lakes and streams and the salt water of oceans and seas The most popular n sh in North America are tuna cod Alaska pollack salmon cat sh and ounder sole Sea Mammals Sea mammals include dolphin whale and seal Invertebrate The invertebrate category includes shell sh most of which have external skeletons or shells The term shell sh is a commercial rather than a scienti c classi cation and includes the invertebrate crustaceans and mollusks Crustacean An invertebrate animal with a segmented body covered by an exoskeleton consisting of a hard upper shell and a soft under shell Mollusk An invertebrate animal with a soft unsegmented body usually enclosed in a shell Examples of crustaceans are shrimp crab lobster and cray sh Mollusks include bivalves univalves and cephalopods Bivalve creatures including clams oysters mussels and scallops are contained within two hard shells that are hinged together The univalves such as conch and abalone have only a single hard shell Cephalopods which include octopus and squid have an almost rubbery soft inner shell which will be familiar to parakeet owners as a cuttlebone Salt or Freshwater The majority of the sh eaten in the United States are taken from salty waters but many also come from freshwater lakes ponds and streams Saltwater sh often have a more distinct avor than freshwater sh Sole however is a very mild avored saltwater sh and is one of several exceptions to the taste generalization Some saltwater sh other than sole are halibut cod ounder haddock mackerel red snapper salmon shark striped bass sword sh and tuna Cat sh perch pike and trout are the most common freshwater varieties Lean or Fat Fish are sometimes identi ed by their fat content but in this case fat is a relative term Fish are not very fatty compared to most other meats Composition In general sh and shell sh are tender because of Lower amount of collagen than land animals 3 by weight versus 15 in land animals Amino acid content of collagen Results in collagen that breaks down at lower temps Muscle structure shorter ber bundles than land animals Carbohydrate lt5 glycogen which breaks down to glucose CHOs contribute slight sweet avor to cooked sh Protein High biological value Fat Rich source of highly unsaturated fatty acids especially omega3 fatty acids Importance of omega3 s known for bene cial health effects including risk of cardiovascular disease and anti in ammatory properties Fish Composition Pigmentation Myoglobin within muscle tissue just as in land animals Concentration of myoglobin depends on characteristic movements of the sh Red or darker colored esh high concentration of slow twitch bers used primarily for long endurance swimming White or pale esh high concentration of fast twitch bers designed for short bursts of energy Higher fat content of sh also darkens esh Astaxanthin redorange pigment with strong antioxidant capacity Found within shell sh and bottomfeeding sh Myotomes Layers of short bers in sh muscle Myocommata Large sheets of very thin connective tissue separating the myotomes Common Fish and Shellfish Grouped by Flavor and Texture Texture Delicate Moderate and Firm Delicate Mild Flavor Cod Crab Flounder Haddock Hake Pollock Scallops and Sole Moderate Flavor Butter sh Lake perch White sh Whiting Full Flavor Mussels and Oysters Moderate Mild Flavor Cray sh Lobster Pike walleye Orange roughy Shrimp Tilapia Moderate Flavor Mullet Ocean perch Shad Smelt Surimi products Trout Sea trout weak sh Tuna canned Full Flavor Blue sh Mackerel Salmon canned Sardines canned Firm Mild Flavor Grouper Halibut Monk sh Sea bass Snapper Squid Tautog black sh Tile sh Wolf sh Moderate Flavor Cat sh Mahimahi Octopus Pompano Shark Sturgeon Full Flavor Clams Marlin Salmon Sword sh Tuna Lean vs Fatty Fish Fat Content of 3Ounce Cooked Portions of Fish and Shellfish Lean Fish Very Low Fat Less Than 25 Grams Total Fat Clams Cod Cusk Blue crab Dungeness crab Flounder Grouper Haddock Halibut Northern lobster Mahimahi Monk sh Perch freshwater Ocean perch Pike northern Pike walleye Pollock Atlantic Ocean pout Orange roughy Scallops Shrimp Red snapper Snow crab Sole Squid Tuna skipj ack Tuna yellow n Whiting Low Fat More than 25 Grams But Less than 5 Grams Total Fat Bass freshwater Blue sh Blue mussels Cat sh Croaker Mullet Oysters eastern Salmon chum Salmon pink Shark Smelt Striped bass Sword sh Rainbow trout Sea trout Wolf sh ocean cat sh Fatty Fish Moderate Fat More Than 5 Grams But Less Than 10 Grams Total Fat Butter sh Herring Mackerel Spanish Salmon Atlantic Salmon coho Salmon sockeye Lake trout Tuna blue n White sh Higher Fat More Than 10 Grams Total Fat Mackerel Atlantic Salmon king Inspection and Certi cation Fish Inspection Voluntary process Conducted by US Dept of Commerce and the Nat l Marine Fisheries Service Determines Wholesomeness of sh and sanitary conditions of processor Shellfish Certi cation Mandatory process regarding harvesting from certi ed waters US Dept of Commerce through the publication of Interstate Certi ed Shell sh Shippers List ICSSLPerishability of Fresh Fish Fish Microbiology Fish esh is sterile internally Bacteria on surface or in intestines rapidly invade all tissues upon death Bacteria are psychrotrophic Why is this important Fish Physiology Upon capture struggle renders all glycogen spent Glycogen upon death would have been converted to lactic acid and act as a preservative by lowering pH In the absence of lactic acid bacteria are uninhibited and spoilage rapidly ensues Perishability of Fresh Fish Fish Fat Chemistry Fish lipids are easily oxidized due to their unsaturated nature Remember Unsaturated bonds are more easily oxidized Trimethylamine Oxide TMAO phospholipid associated with sh fat that is oxidized to produce odorous compound TMA of decaying sh Fishy Odor TMAO conversion to TMA after capture via Oxidation in Fish chemical reaction in which oxygen reacts with fatty acids to produce odorous products Reaction is hastened by enzymes Within sh and indigenous bacteria Trimethylamine TMA is an odorous compound commonly referred to as the fishy smell Fresh fish should not smell shy I I J Selection Storage Preparation Signs of Decay Eyes atten becoming concave Red gills turn brown or dull red Fillets should be at shiny rm and free of gaping Within muscle bers Storage Fish is a PHF because of its high water and protein content Foodbome illness concerns from psychrotrophic bacteria These bacteria ourish under refrigerated conditions thus limiting shelflife Testing for Doneness Flesh becomes rm to touch and begins to ake easily alone muscle ber lines Why do salmon have that characteristic pinkorange hue Sometimes a speci c pigment adds a special hue For example a carotenoid pigment astaxanthin imparts a characteristic orangepink color to certain salmon and trout that feed on insects and crustaceans containing this pigment Fresh and Frozen Fish Whole sh The body is entirely intact Drawn sh Whole sh that have had their entrails inner organs removed Dressed sh The head tail ns and scales have been removed in addition to the entrails Steaks Cut from dressed sh by slicing from the top n to the bottom n at a 90 degree angle at varying thicknesses Steaks contain a portion of the backbone and other bones Some steaks from large sh like tuna are commonly called llets even though they are actually steaks Fillets Made by slicing the sh lengthwise from front to back to avoid the bones A llet is one whole boneless side of the sh Fish sticks Uniform portions cut from llets or steaks They can also be made from minced sh that is then shaped breaded and frozen Gaping The separation of sh esh into akes that occurs as the steak or llet ages Why are some fish higher in mercury than others Mercury makes its way into water from either natural or industrial sources and is taken up into the gills of sh as they swim It stays in the body for long periods of time and small sh store this mercury in their esh Larger sh feed off of small sh This means that larger sh are eXposed to even higher levels of mercury because every time they eat a small sh they add mercury to their esh This is why larger predatory sh and sh with long lives such as sword sh have the highest levels of mercury Fish with Low Moderate and High Levels of Mercury Low Levels of Mercury Salmon Shrimp Scallops Cat sh Tilapia Pollack Clams Sardines Akule Awa milk sh Moi Mullet Opelu Squid Octopus Fish sticks Fish sandwiches Moderate Levels of Mercury Canned tuna particularly albacore Cod butter sh Halibut Mahimahi Grouper Striped marlin Orange roughy Pollock High Levels of Mercury Paci c Blue Marlin King Mackerel Tile sh Shark Sword sh Fish High in Omega3 Fatty Acids 3oz cooked portion More Than 10 Gram Herring Mackerel Paci c jack Spanish Salmon Atlantic king pink Tuna blue n White sh Between 05 and 10 Gram Bass freshwater Blue sh Mackerel Atlantic Salmon chum coho sockeye Smelt Striped bass Sword sh Rainbow trout Omega3 fatty acids A category of polyunsaturated fatty acids that includes eicosapentaenoic acid EPA and docosahexaenoic acid DHA STORAGE OF FISH AND SHELLFISH Fresh Fin sh Fresh sh are best consumed within a day or two of purchase Fish do not store well for longer periods because the esh is much more perishable than animal tissue for several reasons One of these is that all raw seafood carries some bacteria which multiply rapidly above 40 F 4 C Refrigerated Fish should be stored in the coldest portion of the refrigerator It should also be tightly wrapped to prevent odors from coming in contact with other foods Fish bought wrapped in butcher paper should be rewrapped in plastic wrap and then in aluminum foil but prepackaged sh and shell sh can be left in the original package in which they were purchased Any exposure to oxygen increases perishability because the high levels of polyunsaturated fatty acids in sh can be oxidized into compounds that affect odor and taste Spoilage Factors Other factors that can contribute to spoilage are proteolytic enzymes natural toxins and contaminants Proteolytic enzymes break down muscle proteins and provide amino acids for bacterial growth Bacterial enzymes can also break down proteins to amino acids and elevate the levels of histamine a toxin Storing Caviar Caviar is particularly sensitive to oxygen and cannot be left out in the air for more than 1 hour Unopened caviar can be stored in the refrigerator for up to 3 months but once opened it should be consumed within 3 days Fresh Shellfish It is a good practice to eat fresh shell sh the day they are bought If they must be kept the storage requirements are varied and depend on the type of shell sh Most fresh shell sh may be kept alive in cool salty wet environments preferably in the refrigerator Crabs usually sold precooked should be stored in the coldest part of the refrigerator and used within a day or two Once cooked all crustaceans must be refrigerated at temperatures below 40 F 4 C and consumed within 2 days Thawing Fish is best thawed by transferring it from the freezer to the refrigerator one day before preparation once thawed it should be cooked immediately The exceptions are breaded frozen fish or fish llets or steaks weighing less than 12 pound these should not be thawed before cooking because they will become mushy Frozen raw shellfish can also be prepared from the frozen state whereas frozen precooked shellfish can be used as is aft er thawing Chapter 8 Classification of Poultry Species Chicken Cornish game hen Broiler or fryer Roaster Capon Hen fowl baking chicken or stewing chicken Cock or rooster Sex Either either either unsexed male female male Age 56 weeks under 10 weeks under 12 weeks under 4 months over 10 months over 10 months Species Turkey Fryerroaster Young hen Young tom Yearling hen Yearling tom Mature or old Sex Either Female Male Female Male Either Age under 12 weeks under 6 months under 6 months under 15 months under 15 months over 15 months Species Duck Duckling Roaster duckling Mature or old Sex Either either either Age under 8 weeks under 16 weeks over 6 months Species Goose Young Mature or old Sex Either Either Species Guinea Young Mature or old Sex Either Either Species Pigeon Squab Pigeon Sex Either Either Composition of Muscle Composed of muscle cells and bers along with connective tissue Does not contain intramuscular fat but rather fat is stored in abdominal cavity and within the fat pad in the tail Pigmentation white versus dark meat is differentiated by the amount of myoglobin in the muscle Function of myoglobin ironcontaining protein that binds 02 in muscle The Color Chemistry of Muscle Meats Color of muscle is derived from pigment containing proteins primarily myoglobin Myoglobin Ironcontaining protein that binds 02 in muscle Increased amounts of myoglobin found within the most frequently used muscles such as thighs and drumsticks Why is the breast meat in chicken and turkey Whiter than the thigh or drumstick Higher amounts of the red pigmented myoglobin are found in muscles that are used more frequently such as those of the thighs and drumsticks In contrast chicken and turkey breasts are more White because both these types of birds do almost no ying and their meat muscles in these areas thus contains much less myoglobin Wild birds such as ducks have darker breast meat because they actually use the muscles for ying Why is the meat of Wild birds turkeys and ducks darker than farmraised birds Due to the amount of activity and the demand for oxygen to these damaged tissues Determinates of TENDERNESS Location and activity of muscle Animal s age Heredity and breed characteristics Diet In uence of Preparation Inspection and Grading of Poultry Inspection mandatory process Conducted by USDAFSIS Safetyoriented process Antemortem and postmortem inspection for signs of disease Grading voluntary process Qualityoriented process Grade A retail sale blemishfree Grades B amp C processed into poultrybased products Types and Styles of Poultry Dressed Dressed birds are those that have had only the blood feathers and craW removed Readytocook Readytocook poultry is eviscerated free of blood feathers head and feet It is What is typically found in the supermarket and in most food service facilities In readyto cook poultry the internal organs such as the heart liver neck and gizzard part of the bird s stomach have been cleaned and had the fat removed and are frequently put back inside the inner cavity often in their own giblet bag Eviscerate To remove the entrails from the body cavity Convenience For convenience smaller pieces such as halves breasts drumsticks thighs and wings of both chicken and turkey are available Processed Poultry Convenience is also available to consumers and food manufacturers in the form of processed poultry products Processed chicken and turkey are commonly used in canned or dried soups frozen dinners potpies sausages hot dogs burgers and bologna Chicken Nuggets What is in a chicken nugget These are chicken pieces either whole or composed of a paste of a nely minced combination of chicken meat and skin Commercially they are often made with a high proportion of chicken skin 100 calorieskcal per ounce that provides a sticky consistency to hold the nugget together Hormones and Antibiotics The USDA does not allow the use of hormones in the raising of chicken Additives Additives are not allowed in fresh chicken Processed chicken may contain additives however the chicken must be clearly labeled as containing them Common additives used in poultry include salt monosodium glutamate MSG and sodium erythorbate which keeps processed poultry meat from changing color Labeling The United States Department of Agriculture regulates labeling of poultry products and a list of commonly used terms is available on the USDA website wwwfsisusdagovFactSheets MeatampPoultryLabelingTermsindeXasp How Much to Buy Readytocook poultry contains a good deal of inedible bone and unwanted fat which must be taken into consideration when deciding how much to buy A good rule of thumb for most poultry is to buy 12 pound or slightly more per serving The exceptions are ducks and geese which have more fat to melt during cooking resulting in less yield Storage Precautions Storage Poultry is a PHF because of its high content of protein and water lofoodbome illness concerns Salmonella Campylobacter Lowtemperature storage for short duration Uncooked refrigerated poultry should be cooked wi 3 to 4 days The exception to this guideline is ground poultry which must be cooked within 12 days Frozen poultry can be stored for up to 6months if properly wrapped Thawing Frozen Poultry Under cold running water Under refrigeration length of defrost time is dependent on weight Refrigeration is the safest and most economical option Stuffing For food safety reasons the USDA recommends that stuf ng be prepared and cooked separately or if not at least checked with a meat thermometer to con rm that the internal temperature is at least 165 F 74 C Brining What is brining It is soaking food in salty water a brine Applying this method to poultry prior to cooking increases its water content resulting in a more juicy avorful meat The poultry whole or pieces is placed in a large nonreactive pot and covered with a brine solution The simplest brine solution is water and salt but sugar herbs and spices can also be added Why is there so much concern about food safety in poultry preparation About one fourth of all chickens in the United States carry Salmonella and about half carry Campylobacter jejuni A national survey showed that although only about 4 of broilers tested positive for Salmonella before processing the number rose to 36 after the carcasses had been subjected to scalding defeathering eviscerating and chilling For this reason anything that comes in contact with raw poultry including hands cutting boards sinks utensils dishes and counters should be cleaned and sanitized afterward Determining Doneness Accurate determination of doneness requires the use of a thermometer inserted into the thickest portion Minimum internal temperature 165 F At this temperature juices will have turned from pink to clear Timeweight charts are helpful for cooking large birds Use of popup indicators The popup indicators that some poultry producers place in turkey breasts are not always reliable so check for other signs of doneness A thermometer placed in the center of any stuf ng must reach a minimum temperature of 165 F 74 C Color Change When the skin on ovenroasted chicken or turkey reaches a golden brown color it is time to test for doneness The juices coming out of the bird should have turned from pink to clear and a bit of bone should be showing on the tip of the legs Touch When pressed rmly with one or two ngers the welldone bird s esh will feel rm not soft White meat may be rmer than dark meat in part because certain proteins have a higher gelforming ability in white muscle than they do in the dark muscles TimeWeight Charts Timeweight charts appear on the packaging of all frozen and many fresh birds It takes about 1 12 hours in a 350 F 177 C oven to thoroughly cook a 35 pound chicken Roasting or Baking Both whole or individual pieces of poultry can be roasted baked A heavyduty roasting pan is used for the best result Some people place the bird breast up directly on the pan which promotes the loss of tasty juices to be collected later or breast down for more juicy breast meat The bird is then placed in an oven set at between 325 F and 350 F 163 C and 177 C and baked for the allotted time up to 15 hours for a whole chicken 20 to 25 minutes per pound for poultry up to 6 pounds 15 to 20 minutes per pound for poultry up to 15 pounds 12 to 15 minutes per pound for poultry over 15 pounds Aroma of Roasting Chicken The classic aroma of roasting chicken comes from volatile compounds such as carbonyls and hydrogen sul de Truss To tie the legs and wings against the body of the bird to prevent them from overcooking before the breast is done It is also for presentation purposes Trussing Poultry 1 Tuck the wings under the back to avoid overcooking 2 Loop a butcher string three times as long as the poultry as shown 3 Pull the ends of the string together and run them the breastbone 4 Turn poultry over tuck string under wings and tie it over the neck ap Basting Basting chickens and turkeys helps prevent drying of the skin and meat This involves using a wide spoon or brush or a special tool called a baster to periodically cover the bird with liquid from the drippings melted butter or barbecue or other sauce Duck and goose do not need to be basted they are so high in fat that they are selfbasting Stuffing refers to anything that is placed in the cavity of a bird during cooking This is usually the familiar breadcrumb or cornbread stuf ng however other foods such as vegetables and meats are sometimes stuffed in the bird s cavity The main ingredient of stuffmg dressing is cut cubes of dayold bread packaged stuffing mixes or rice This starchbased foundation absorbs the juices released during cooking which is why it is important that it be dried otherwise the dressing will be mushy Carving Roast Chicken 1 Steady the chicken on a sanitary cutting board To remove the leg slice through the skin holding the leg to the breast 2 Push the leg down to partially dislodge the joint cut through the meat between the leg and breast then cut through the joint 3 To separate the breast meat brace the chicken with a fork slicing just inside the keel bone Move the knife downward pulling cutting the breast section away from the rib cage Broiling or Grilling Except when cooking a whole bird on a spit over hot coals only cutup poultry is used for broiling or grilling It is frequently marinated or coated with butter and seasonings before being broiled or grilled It is frequently marinated or coated with butter and seasonings before being broiled or grilled In the interest of food safety marination must take place under refrigeration Frying Poultry pieces can be sauteed panfried deepfried or stirfried Saut ing Small poultry pieces are placed in a skillet or pan with a small amount of oil for quick preparation Pieces must be turned to assure adequate doneness PanFrying Panfried chicken pieces are usually breaded or oured before they are fried over high heat in approximately 14 inch of fat The breading adds texture and avor and keeps moisture from being lost from the fried food it also allows heat to be transmitted to the food without its absorbing as much fat DeepFrying Deepfrying poultry pieces that have been breaded oured or battered involves submerging them completely in oil heated to between 325 F and 350 F 160 C and 180 C StirFrying Stirfrying is lightly frying bitesize pieces of boned chicken while stirring them frequently in a tiny amount of oil MoistHeat Preparation Braising Although braising also called fricasseeing can be applied to any poultry it is of particular value when it comes to preparing older tougher birds The slow moist heating tenderizes the meat and makes it easier to chew Stewing Any whole or cutup fresh poultry can be covered in cold salted water and heated to the boiling point at which point the heat is immediately lowered to a simmer Poaching Chicken pieces can be poached fairly quickly in a small amount of water The chicken pieces such as breasts are placed in a frying pan and covered with 1 13 cups water The water is brought to a boil and then reduced to a simmer and the chicken is cooked about 10 to 15 minutes or until tender Microwaving Microwave ovens do not always heat food deeply or evenly enough and power levels vary from brand to brand so it is suggested that stuffed poultry particularly turkeys be prepared in a conventional oven Chapter 10 FUNCTIONS OF MILK IN FOODS Milk is itself a beverage but there are also all sorts of drinks that use milk as a base smoothies milk shakes yogurt drinks eggnog kefir and more Food products primarily made from milk include cheese yogurt sour cream and whipped cream to name just a few Many foods rely on milk or ingredients derived from milk including pizza cheese souf s sandwiches casseroles quiches sauces processed meats soups dressings infant formulas coffee creams food bars sports nutrition products breads cereals cakes pies puddings cookies ice cream milk chocolate caramels frozen yogurt and many other desserts Milk Ingredients Used by the Food Industry Caseins The major protein found in milk can be extracted from skim milk via acidification or enzyme precipitation They are used to improve nutritive value medical foods and palatability of imitation cheese Caseinates Made from casein by adding sodium calcium potassium or combinations of these salts to make them water soluble They are added to food bars medical foods soups sauces whipped toppings and bakery products Hydrolysates Manufactured by the enzymatic hydrolysis of milk proteins This treatment improves the proteins stability solubility viscosity emulsification and whipping ability Lactose Improves the waterholding capacity of processed meats ham texture of frozen desserts such as ice cream and color of baked goods browning ability Milk Protein Concentrates MPC and Milk Protein Isolates MPI These casein and whey proteins are isolated from fresh nonfat milk and are rich in bound calcium Their more natural milk avor makes them suited for several foods such as infant formula weight loss products sports nutrition items cheese products and liquid beverages Whey Powder Crystallizing whey creates a powder high in lactose and minerals that can be used for infant formulas baked items and confectionaries Whey Protein Isolates Concentrated whey that is high in protein but low in lactose and minerals Used for dry miX beverages nutrition bars protein fortified food and sports nutrition products COMPOSITION OF MILK Milk Water 874 and Milk Solids 126 Milk Solids Milk Solidsnotfat MSNF 89 and Milk fat 37 MSNF Lactose 48 Minerals 07 Protein 34 Protein Casein 28 and Whey Protein 06 If an individual is lactose intolerant What are they de cient in Lactase the enzyme that breaks down lactose Carbohydrate Lactose or milk sugar is the primary carbohydrate found in milk 12 grams per 8ounce cup When bacteria in milk metabolize lactose lactic acid is produced The avor of cheeses and fermented milk products such as yogurt and sour cream is in part derived from lactic acid Lactose Intolerance This condition results in an inability to digest lactose the form of sugar found in milk Medical food A food to be taken under the supervision of a physician and intended for the dietary management of a disease condition for Which distinctive nutritional requirements are established by scientific evaluation Proteins predominantly casein and whey Casein 80 of protein in milk Coagulating proteins forming the curd in cheese production Whey 18 of protein in milk Liquid portion of milk remaining after cheese production Further processed for use as supplemental powders emulsifying agents for food industry use and also food additives such as thickeners that are commonly used for enhancing the structural characteristics and mouth feel of food products Milk proteins in food improve avor textural properties to the final product in uential in moisture retention Milk Proteins Approximate Percentage of the Major Proteins Found in Milk Protein Total Protein Caseins 79 ocCasein 43 BCasein 20 xCasein 12 yCasein 4 Whey Proteins 18 BLactoglobulin dLactalbumin Immunoglobulins Serum albumin NNUIO Milk Additives Fortification adding nutrients to a product that wasn t there before Vitamin D Why Due to emulsi cation Vitamin A rBGH not classi ed as a food additive by the FDA Hormone given to dairy cattle to increase production of milk by 10 per serving Steroid use is not permitted in dairy cattle but is permitted in cattle for meat production You choose rGBHfree milk options are available Color Compounds Factors that contribute to the color of milk are fat colloidally dispersed casein and calcium complexes and water soluble ribo avin B2 Why does nonfat milk have a bluish hue Removing any of the fat eliminates a proportional amount of carotenoid pigments and solids resulting in the color changing from a yellowish White to the bluish hue seen in fat free nonfat milk PURCHASING MILK Grades Milk is graded according to its bacterial count The highest grade Grade A has the lowest count The law requires that all Grade A milk and milk products crossing state lines be pasteurizedMilk Processing Pasteurization Process of heating milk to destroy pathogenic bacteria thus increasing shelflife Average Temperature 161F for 15sec Determinant of success presence of enzyme alkaline phosphatase Destroys enzymes causing spoilage and most nonpathogenic bacteria Minimal impact on nutritional value and avor Ultra pasteurization A process in which a milk product is heated at or above 280 F 138 C for at least 2 seconds Ultrahightemperature UHT milk Milk that has been pasteurized using very high temperatures is aseptically sealed and is capable of being stored unrefrigerated for up to 3 months Homogenization A mechanical process that breaks up the fat globules in milk into much smaller globules that do not clump together and are permanently dispersed in a very ne emulsion Coagulate To clot or become semisolid In milk denatured proteins often separate from the liquid by coagulation How is milk homogenized The mechanical process of homogenization pumps the milk under a high pressure of 2000 to 2500 pounds per square inch through a machine that contains ne holes which breaks up the fat globules This decreases the fat globule size to less than 2 microns The now very small droplets of milk fat are surrounded by a lipoprotein membrane which prevents them from joining together and separating out The liquid and fat components of the milk are now in effect homogenized Temperature OF 0C Time Type of Pasteurization Refrigeration Required 1450 630 30 minutes LowTemperature LongerTime LTLT Yes 161 O 7 1 5O 15 seconds HighTemperature ShortTime HTST Yes 2120 1000 001 second HigherHeat ShorterTime HHST Yes 4 2800 1380 2 seconds or more UltrapasteurizationYes but product has longer shelf life 2800 3020 1380 1500 2 6 seconds UltrahighTemperature UHT Not until opened Proteins Precipitation amp Coagulation Milk proteins are dispersed throughout milk in the form of Casein and Whey pH of milk 66 At this pH milk proteins are stable as in uid milk Under certain conditions milk proteins precipitate and coagulate to form a clot or curd These conditions include acidic ingredients lemon juice the addition of enzymes rennin and growth of microorganisms Rennin An enzyme obtained from the inner lining of a calf s stomach and sold commercially as rennet Manipulation of Milk Proteins Addition of Acid Addition of Heat Addition of Enzymes Casein Precipitates and Coagulates No Reaction Precipitates and Coagulates Molecules dehydrates forming skin on top of milk Whey No Reaction Precipitates No Reaction Proteins adheres to bottom of saucepan resulting in scalded avor Why does a skin form on the surface of heated milk This is caused by the evaporation of water Which is accompanied by an increased concentration of casein fat and mineral salts This thin skin scorches easily in addition it can trap steam that is trying to escape and cause the milk to boil over Several steps can be taken to avoid this problem including using a lid continual stirring during heating oating a small pat of butter on top of the milk or in the case of hot chocolate adding Whipped cream or marshmallows Milk Coagulates as pH Drops Normally the casein proteins are negatively charged causing them to repel each other in the fluid milk Coagulation of these casein proteins occurs when the negative charges are neutralized by the hydrogen ions H1 from acid When the pH drops to 46 casein becomes very insoluble and precipitates readily into a curd This is milk s isoelectric point the negative and positive charges on the molecules ie casein balance each other and the overall charge is neutral Milk products coagulated with acid are lower in calcium than those coagulated with an enzyme because the acid releases calcium from the casein molecules causing it to be lost in the whey acid calcium phosphocaseinate gt neutral casein gel Ca lost in whey Whipped Cream Cream expands two to three times its volume when whipped The stability of milk foams especially whipped cream is dependent on several factors the fat content the temperature of the cream the age of the cream the sugar content the equipment used to whip the cream and the length of whipping time Fat Content The higher the fat content of the cream the more stable the whipped cream will be Solid fat particles create a more rigid foam Heavy whipping cream beats more easily than lowerfat whipping creams but becomes lumpy and buttery when over beaten Most whipping creams are sold unhomogenized to allow for easier aggregation of the fat globules When the cream is homogenized much of its protein surrounds the now smaller and more numerous fat globules instead of being available to envelop the air bubbles that are essential for foam formation Temperature Cooling cream increases its viscosity or rmness and its tendency to clump For best results refrigerate the cream bowl and beaters at 45 F 7 C or less for at least 2 hours before whipping Cream allowed to warm to room temperature or even to above 50 F 10 C has more widely dispersed fat globules which reduces the cream s ability to be whipped and creates a softer texture Age The older that the cream is the greater will be its viscosity and ability to foam Sugar Sugar increases the stability of whipped cream but it should be added gradually toward the end of the whipping period If added earlier it will increase the whipping time and reduce overall volume and rigidity by delaying the clumping of fat Whipping Time Physical agitation of the cream is necessary because it disrupts the phospholipid membranes surrounding the fat globules preventing them from aggregating Whipped Evaporated Milk The high concentration of milk solids in evaporated milk makes it possible to whip it to three times its volume but the avor texture and stability are less acceptable than they are in whipped cream The avor of evaporated milk has a tendency to overpower other avors thus it is best used with highly avored foods Evaporated milk foams are less stable than whipped cream foams partly because of the former s lower viscosity and lower fat content STORAGE OF MILK PRODUCTS Refrigerated Milk No more than 3 weeks Yogurt Best consumed within the rst 10 days but can last up to 3 to 6 weeks If it separates simply stir the liquid back into the curd before serving Buttermilk Best when used within 3 to 4 days aft er purchase because it will continue to sour but it can last up to 3 or 4 weeks Sour cream Unopened up to 1 month but is best when used within a few days Chapter 12 A few examples of how eggs are used in food preparation are listed below Giving a foam structure to cakes and meringues Thickening custards and puddings Adding color to lemon meringue pie and eggnog Emulsifying mayonnaise and hollandaise sauce Leavening souf s and popovers Binding ingredients in meatloaf and casseroles Coating foods prior to breading Glazing pastries and breads Clarifying liquids for soup COMPOSITION OF EGGS Structure The egg has ve major components the yolk albumen egg white shell membranes air cell and shell Shell composed of calcium carbonate Porous to allow exchange of gases Color is not an indicator of quality Protected by cuticle or bloom waxy coat This prevents bacterial translocation from the outside into the inside sterile portion of the egg That bloom is also responsible for slowing the moisture loss from an egg as an egg tries to equilibrate within its environment It slows the moisture loss Shell Membranes Between the egg white and the shell are two membranes an inner and outer shell membrane These press up against the shell and protect the egg against bacterial invasion Yolk composed of lipids cholesterol lecithin acts as an emulsi er and vitamin A Color intensity depends on the diet of the hen Feed additives to increase color intensity of your eggs Pigments in the chicken feed such as betacarotene cause colors ranging from pale yellow to deep red Natural yelloworange substances such as marigold petals are sometimes added to the chickens feed to enhance the color of their egg yolks Arti cial color additives are not permitted Coagulates at 14916OF Anatomy of an Egg Air Cell pocket of air at the larger end of the egg What happens to the air cell as eggs age Albumin Egg White composed mostly of protein water antimicrobial compounds and B vitamins Multiple proteins of differing content and viscosity Coagulates at 144149F Chalaza pl chalazae The ropy twisted strands of albumen that anchor the yolk to the center of the thick egg white Vitelline membrane The membrane surrounding the egg yolk and attached to the chalazae Protein Content of Egg White Protein Amount Properties Ovalbumin 54 Denatures easily Conalbumin 13 Antimicrobial complexes iron Ovomucoid ll Inhibits enzyme trypsin Unidenti ed 8 Mainly globulins Lysozyme 35 Antimicrobial Ovomucin 15 Viscous reacts with Viruses Flavoprotein 08 Binds ribo avin Proteinase inhibitor 01 Inhibits enzyme bacterial proteinase AVidin 005 Binds the B Vitamin biotin raw egg White only Egg Inspection amp Grading Mandatory and conducted by the USDA USDA Grades AAbest quality A and B Based on interior and exterior quality Albumin Index ratio of height to Width of albumin AKA Haugh units Egg Grading Candling intact eggs Viewed over a light source shell integrity air cell size yolk placement blood spots etc Commercial egg grades are assigned based on both interior and exterior quality Interior quality is primarily determined by candling The exterior quality is determined by the cleanliness of the shell the shape of the egg and the presence of shell irregularities such as pimples calcium deposits and weak shells How does candling reveal whether an egg is fresh or aged The yolk in a fresh highquality egg is suspended tightly by the chalazae seen in candling only as a slight shadow The yolks in older eggs on the other hand are surrounded by thinning clearer egg whites and deteriorating chalazae These older yolks lie closer to the shell because they are no longer suspended well by the chalazae they are looser in consistency and cast a darker shadow The egg s air cell too becomes wider or moves as the egg ages Grade AA eggs must have an air cell depth smaller than 18 inch Grade A eggs are limited to 316 inch and Grade B eggs have no limit to the size of their air cell Haugh Units The freshness of an egg can be detected by cracking it open onto a at surface and looking at the height of its thick albumen Fresh egg whites sit up tall and fi rm whereas older ones tend to spread out Haugh unit a numerical value re ecting an egg s freshness is obtained by mathematically combining the thick albumen height with the egg s weight and then using a formula or table to convert this number into a Haugh unit As Haugh units decrease so does egg quality which is re ected in grading Grade AA is given to eggs with a Haugh unit of 72 or higher Grade A for a measure of 60 to 71 and Grade B for a measure of 31 to 59 Appearance Grading can also be based on the appearance of eggs broken on a at surface Graders evaluate the quality of an egg by observing the thickness of the albumen the prominence of the chalazae the roundness and firmness of the yolk and the shape cleanliness and texture of the shell Reference protein A standard against which to measure the quality of other proteins Eggs are a source of several minerals especially selenium iodine zinc and iron Unfortunately the iron in egg yolks is not very available because it binds to phosvitin an egg protein that inhibits absorption Functionality of Eggs Emulsion A liquid dispersed in another liquid with which it is usually immiscible incapable of being mixed Emulsifying Agent one that binds with the immiscible liquid Lecithin within egg yolks acts as an emulsifying agent to stabilize these emulsions Factors In uencing Emulsi cation Properties Freezing decreases the activity due to the disruption of the yolk and its contents Pasteurization neutral Acidity decreases the emulsion s properties therefore you will see separation if it is highly acidic Salt increase the stability Binding The high protein content of eggs makes them excellent binders Fish chicken vegetables and other foods are often dipped in beaten egg and then rolled in breading batter our or cereal During cooking heat coagulates the eggs protein which then acts as an adhesive binding the other ingredients to the surfaces of the cooked material Egg Foaming Properties Egg whites beaten to incorporate air resulting in volume increases of 6x to 8x the volume of original egg whites Examples of Aerated or EggLeavened Foods Angel Food Cakes souf es Meringues Old Eggs versus Fresh Eggs Fresher eggs produce a very stable rm due to the thickness of the egg whites Old eggs produce a very fragile rm because there might be an increase volume but they have thinner whites and although they will uff up and foam up they re thin whites with little protein that has broken down allow it not to maintain the foam integrity Why do beaten egg whites make a stable foam Vigorous beating or whisking of egg whites breaks the links between protein molecules causing the protein molecule coil to unwind or become denatured A foam structure is created when the unfolded proteins rearrange to construct lms around the air cells When the airy foam is heated its air cells further expand after which the egg proteins coagulate solidifying the egg protein to create a rm stable structure higher in height than the same food made without eggwhite foam Food Cereal grains and pasta Noodles pasta Pancakes crepes waf es Desserts Cakes pastries Candy Custards puddings Doughnuts croissants Ice cream Egg dishes Meringues souf es Omelets scrambled poached Fish products and meat Fish products surimi Meat patties sausages Salad dressings Mayonnaise salad dressing Function of Eggs Color avor nutrition Flavor coagulation Foaming coagulation color Inhibition of crystals Coagulation avor Texture avor Emulsification texture Foaming Coagulation avor Binding by coagulation Binding by coagulation Emulsification Why were copper bowls once commonly used to whip egg white foams It was long a common chef s practice to use copper bowls made speci cally for beating egg whites A unique reaction between the copper and the egg whites occurs trace amounts of copper from the bowl combine with an eggwhite protein conalbumin allowing the air bubbles in the foam to expand to a larger size as they are beaten Although copper bowls did improve the whipping properties of eggs they are no longer recommended because of toxicity risks associated with excess copper Beating Technique Egg whites are best beaten with an electric mixer but a wire whisk or a doublebladed rotary egg beater can also be used Whichever device is used the key is to whip the egg whites into very fine delicate bubbles Testing for Doneness Testing for doneness consists of stopping lifting the beaters out of the foam and seeing how the eggwhite peaks form Initially the eggwhite foam forms soft shiny peaks that droop over without holding their shape and the whipped foam slides around in the bowl Avoiding Over whipping Excessive beating of egg whites occurs when the peaks stand tall dry and are no longer shiny In addition the protein lms surrounding the air cells rupture creating bubbles that are too large and unstable Temperature The bowl beater and eggs should be at room temperature The decreased surface tension of roomtemperature egg whites allows them to whip more easily and to a larger volume than cold eggs However the stability of the foam deteriorates with continued exposure to room temperature Bowl Deep bowls with rounded bottoms sloping up into the sides are best because they allow the egg whites to be picked up by the beater Sugar Sugar stabilizes eggwhite foam but it also inhibits the mechanical coagulation of proteins necessary for foam formation Therefore it is best to add sugar near the end of the whipping time or volume may be compromised Fluid Adding uid to egg whites increases the foam volume up to 40 percent but decreases its stability Salt Salt decreases the stability and volume of eggwhite foam and for that reason is rarely added to egg whites Acid Normally whole eggs are relatively neutral in pH 7 0 to 76 but egg whites by themselves tend to be alkaline about 84 pH In fact alkalinity increases with age as the loss of carbon dioxide increases the pH of the egg whites up to 92 Interfering Eggs are often used in the preparation of frozen desserts such as ice cream because they interfere with the formation of ice crystals Similarly in some candies eggs are used to block the formation of large sugar crystals to create a smoother more velvety texture Clarifying Egg whites are often used to clarify liquids This is done by dissolving egg proteins especially egg whites albumen in cold liquid which is then heated This causes the proteins to solidify to attract other particles that may be clouding the liquid and to rise with them to the surface for removal Color An egg s yolk contributes a golden brown color to yellow cakes cookies pastries and even rolls breads and eggcontaining noodles In uence of Prolonged Shelflife Shrinkage air cell enlarges as moisture is lost through permeable egg shell pH increases to pH 9 as C02 escapes through permeable egg shell Makes eggs easier to peel if preparing as hardcooked eggs Liquefication Whites thin as albumin proteins breakdown Yolks atten and enlarge Egg Safety Eggs are considered a PHF due to their high protein and high water content Bacteria of Concern Salmonella Listeria Whole eggs are often irradiated to destroy bacteria on egg shells Liquid eggs are pasteurized to ensure food safety Safe Cooking Temperatures USDA 160F for at least 15 seconds FDA 145F for at least 15 seconds Which temperature guide should you use Iron Sul de Green Egg Syndrome Upon exposure to high heat for prolonged time the sulfur in the egg Whites reacts with the iron in the yolk to form iron sul de Green ring around the yolk is an indicator of overcooking Who overcooked the eggs Egg Substitutes Convenient forms pasteurized to ensure safety cholesterolfree Two Basic Types Complete Egg Sub made from soy or milk proteins AlbuminBased Subs Egg Substitute Composition Vegetable oil replacing fat of egg yolk Bcarotene for color Milk proteins for replacing albumin proteins may also be added to albuminbased substitutes Changes in Prepared Eggs Effects of Temperature and Time The key to cooking eggs is to keep the temperature low andor the cooking time short Heating eggs at high temperatures andor for long periods of time diminishes the eggs texture avor and color DryHeat Preparation Dryheat preparation of eggs primarily involves frying and baking Egg dishes that are commonly fried are fried eggs scrambled eggs and omelets Baked egg dishes include shirred eggs meringues both soft and hard and souf es Frying A frying pan a saut pan omelet pan or even a griddle can be used to fry eggs Prime season To seal the pores of a pan s metal surface with a layer of heatedon oil Sunnyside up The egg is cooked until the White is set and the yolk is still soft The egg is not ipped MoistHeat Preparation Over easy The eggs are ipped over when the whites are 75 percent set Cooking continues until the whites are completely cooked but the yolks are still soft Over medium The same as over easy except that the yolks are partially set Over hard The same as over easy except that the yolks are completely set Scrambled Eggs Scrambled eggs are beaten while raw until well blended and may be seasoned with salt and pepper or other seasonings Liquid in the form of milk cream or water may be added to impart more body andor avor and a soft creamy texture The added liquid a tablespoon or less for each egg creates steam during cooking which lifts the eggs and makes them lighter and uffier Too much liquid makes the eggs watery and forms small tough curdlike masses Shirred Eggs Whole eggs that are baked and served in individual dishes are called shirred eggs Meringue A meringue is an egg white foam used in dessert dishes as a pie topping a cake layer or as frosting It may also serve as a dessert on its own or be combined in other ways with dessert ingredients Meringues are made by whipping egg white into foam and adding sugar the amount of which determines whether the meringue is soft or hard Shrinking To prevent the meringue from shrinking back and leaving an unsightly gap around the outside edges of the pie it should be spread to slightly overlap the entire perimeter of the crust Weeping Also known as syneresis weeping may be caused by underbeating the eggs which leaves unbeaten whites on the bottom of the beating bowl or by undercoagulation created for example by placing meringue on a cold pie filling Beading Undissolved sugar is the main cause of beading but overcooking overcoagulation also contributes to this phenomenon Beading can be avoided by using shorter cooking times and increasing the temperature up to 425 F 218 C Souffl s A souf e is actually a modified omelet The main ingredients of a souf e are a thick base generally made from a white sauce or pastry cream an eggwhite foam and avoring ingredients Initially the egg yolks and whites are separated Hard or Soft Boiled HotStart Method Soft 3 to 4 minutes Medium 5 to 7 minutes Hard 12 to 15 minutes ColdStart Method Soft 1 minute Medium 3 to 5 minutes Hard 10 minutes Why is vinegar added to boiling water when cooking eggs Vinegar is often added to the water used to hardboil eggs There are two reasons for this First the acid in the vinegar dissolves the external surface of the shell making it easier to peel away Secondly if the egg cracks while boiling the vinegar will encourage the egg white to harden preventing the entire egg from leaking out into the water Why do boiled eggs sometimes crack Eggs crack because the pressure created by fastheating water pops the shell Although simmering hardcooked eggs makes them prone to cracking this can be avoided by rst warming eggs to room temperature in a bowl of warm water Another way to reduce the chances of cracking is to push a sterilized pin or needle through the large end of the shell where the air cell is located To reduce cracking still further a spoon or other utensil may be used to place the eggs gently in the water Coddling Coddled eggs are prepared by breaking an egg into a small cup called a coddler made of porcelain or heatproof glass with a screwon top and submerging the whole coddler in simmering water until the egg is cooked Th e coddler should be buttered or greased before adding the raw egg Poaching Eggs are poached by being cracked and simmered in enough water to cover the egg by at least twice its depth Fresh USDA Grade AA eggs are best to use for 10 poaching because the whites are rmer and less likely to spread out in the water and create streamers oating strands of partially cooked egg whites Custards Custards are mixtures of milk and or cream sweeteners sugar honey avorings vanilla nutmeg etc and eggs or egg yolks Custards are thickened by the coagulation of egg proteins during cooking These egg proteins denature when heated and recombine to form a network that sets or coagulates at the right temperature to form the solid gel of a custard Microwaving Eggs cook extremely rapidly in a microwave oven so special caution should be taken to avoid overcooking Manufacturer s instructions should be followed for microwave egg cooking Whole eggs with intact shells should never be microwaved because steam expanding within the shell can cause them to burst Fried A browning dish is required to fry an egg in a microwave and should be preheated on full power for 2 minutes plus one additional minute for each egg being fried Shirred Shirred eggs are cooked in individual containers and are ideal for cooking in a microwave oven Scrambled Before scrambling 1 teaspoon of butter is melted in a 2cup glass measure by setting the microwave very brie y on high The beaten eggs are placed in the measuring cup and microwaved on high for 20 seconds The egg mixture is then stirred and the heating and stirring process is repeated one or two more times Poached To poach an egg 14 cup of water with a dash of vinegar and salt is heated to a boil in a custard dish or lcup glass measure The egg is dropped into the hot water and the yolk is pierced with a toothpick Omelet Omelets can be prepared in the microwave by using a browning dish or 9inch pie plate 11 Storage eggs Eggs that are treated with a light coat of oil or plastic and stored in high humidity at low refrigerator temperatures very close to the egg s freezing point 29F 32F l 5C OC Drying eggs is a simple process Whole eggs or separated yolks are spraydried to create a ne powder Which is mixed with anticaking substances to prevent clumping Egg Whites are dried in different ways to form granule ake or milled textures Rehydrating Dried Eggs Dried eggs are used in food preparation by adding them to water or by sifting them with dry ingredients 12 Slide 1 Food Preservation is all about applying the basics of food science to preserve food maintain its nutritive qualities and its sensory qualities throughout extended shelf life Slide 2 Food Spoilage Food ingredients have a limited shelflife due to their biological nature living matter For this reason food preservation is a MUST Highly perishable foods include those that contain increased amounts of protein and water spoil the fastest and need to focus on the most Three Major Types of Changes Occur in Foods Biological Changes Chemical Changes and Physical Changes Fermentation The conversion of carbohydrates to C02 and alcohol by yeast or bacteria Dehydrate To remove at least 95 of the water from foods through exposure to high temperatures Freezedry To remove water from food when it is in a frozen state usually under a vacuum Sublimation The process in which a solid changes directly to a vapor without passing through the liquid phase Cure To preserve food through the use of salt and drying Sugar spices or nitrates may also be added Slide 3 Spoilage vs Contamination Food Spoilage Detectable changes occurring in food that affect any one of the following attributes of food appearance taste texture or odor Food Contamination Commonly undetected growth of microorganisms in food which affects the safety of the food Slide 4 Changes Affecting Spoilage Biological Changes microorganisms such as bacteria yeasts and molds Highly impacted by the moisture content in the food Chemical Changes brought about by enzymes which catalyze reactions to breakdown food Enzymes are sometimes indigenous in the food themselves sometimes they can be secreted by microorganisms Physical Changes evaporation loss of water and separation of tissues and components of food loss in color loss in structural integrity in and in itself Slide 5 Drying We rely on science to preserve the food Decreasing the water content of food renders most microorganisms unable to grow Remember drying does not kill microorganisms but rather MO s can enter a dormant Aw measurement of water content in food required for preservation is generally below 06 or 60 Slide 6 Refrigeration When fruits and vegetables are harvested they continue to ripen and respire Refrigeration slows the rate of ripening by slowing enzyme reactions involved in ripening influencing chemical changes Low temperatures also slow the rate of microbial growth influencing biological changes Slide 7 Freezing Microorganisms must have source of moisture to grow In the frozen state moisture is bound within ice rendering it unavailable to microorganisms Chemical and physical reactions are slowed yet available oxygen will allow these reactions to continue at a slower rate For this reason vegetables are typically blanched partially cooked before freezing to destroy ripening enzymes Slide 8 provides a reference of common pH and common foods pH 50 pH 80 microorganisms tend to proliferate which is why many foods are acidified Slide 9 Picklin 9 Bacteria grow best at neutral pH pH 7 Most MOs cannot tolerate environments with a pH lt 46 Many fruits are acidic enough lt4 to discourage bacterial growth Addition of acids such as vinegar lowers pH and limits microbial growth Other examples of acids used in pickling are those resulting from fermentation by lactic acid bacteria Slide 10 Fermentation Growth of bacteria andor yeast under conditions of limited to no available oxygen renders a fermentation reaction Microorganisms consume energy source and produce ethanol and carbon dioxide Ethanol as an alcohol limits microbial growth if it is in sufficient quantities which is why fermentation and the alcohol that is produced during fermentation reaction inhibits microbial growth Fermentation lowers the pH of the product and in the case of wine beer liquor etc the alcohol content limits further microbial growth Commonly fermented foods include pickles cucumbers olives and cabbage Slide 11 Canning good for the healthy Food sealed in cans or jars and heated to high temps At 15 psi pounds per square inch water boils at 252 oF allowing for greater heatinduced microbial destruction lntense pressure pulls a vacuum on the food leaving no available 02 for M0 growth Heat destroys MOs and enzymes yet it does not destroy bacterial spores like those produced by C botulinum Slide 12 Irradiation lonizing radiation destroys chemical bonds within enzyme systems and DNA in microorganisms that influence food deterioration and food safety Also known as cold sterilization Considered a Food Additive by the FDA Not all produce can be successfully irradiated Commonly irradiated foods include shell eggs eggs in their shells chicken sprouts FDA radura symbol requires inclusion of radura symbol on foods which have been irradiated or food packaging must contain these words treated with radiation or irradiation Slide 13 Edible Coating Purposes Barriers to 02 gases and moisture loss thus lengthening shelflife lmproved handling and transportation characteristics lmproved appearance Vehicle for added flavors antioxidants etc Types of Edible Coatings lipid CHO and proteinbased coatings Waxes are the most common Common Foods eggs peppers eggplants apples bananas pumpkin last through the winter due to its edible coating Slide 14 Other Methods of Preserving Food Pasteurization is most often used in dairy products and fruit juices destroys nonsporeforming pathogenic microorganisms Curing high concentrations of salt added to foods for the purpose of salt binds waters and renders it unavailable for microbial growth Curing is often combined with smoking as a food preservation method Chapter 11 Cheese is a preserved food made from the curd or solid portion of milk Adding certain enzymes and or acid to any type of milk causes the casein proteins and fat to coagulate and separate from the liquid portion or whey Making cheese involves removing moisture from the curd to varying degrees after the whey is drained The whey also contains dissolved materials such as proteins which can be processed to produce cheeses and other foods England Cheddar Cheshire France Camembert Brie Italy Parmesan Gorgonzola Netherlands Edam Gouda Switzerland Gruyere Emmentaler United States Colby Moisture Content The goal of making cheese is to remove water from the milk until a solid mass or curd remains During this production process the moisture content of cheese decreases especially during aging As cheeses age they become drier and harder Fresh Fresh cheeses also called country cheeses are soft whitish in color and mild tasting They are highly perishable because their moisture content is over 80 percent and they are not aged They include cottage cheese and cream cheese and ricotta farmer s pot and feta cheeses Soft Soft cheeses such as Brie Camembert and many Hispanic cheeses are aged for just a short time Water content ranges from 50 to 75 percent Semihard Semihard cheeses contain 40 to 50 percent moisture The bestknown examples are Roquefort blue Muenster brick Gouda Edam Port du Salut Gorgonzola and Stilton Hard The moisture content of hard cheeses ranges from 30 to 40 percent Cheddar and Swiss are examples of hard cheeses Very hard Parmesan and Romano are classi ed among the hardest cheeses Very hard cheeses will not slice easily but are easily grated or crumbled They are aged the longest and have a water content of approximately 30 percent Cheese Production 1 Coagulation curdling of casein in milk by the addition of acids andor enzymes Example Acids lemon juice or lactic acid Example Enzymes rennin or pepsin 2 Curd Processing cutting heating and salting 3 Aging holding of cheese in temperature and humiditycontrolled environment for 4 weeks up to 2 years Curing environmental conditions of holding the cheese Temperature and relative humidity Holding an under control condition Ripening biochemical and physical changes Bacteria mold and enzymes in uence texture and avor of nal product Cheese Ripening There are three main steps in the ripening of cheese The rst is glycolysis in which lactose is metabolized to form acetic and propionic acid carbon dioxide esters and alcohols this metabolism is initiated by the bacterial starter and other microbials present in milk Next is lipolysis the breakdown of fat molecules to free fatty acids which are then further broken down to ketones lactones and esters by enzymes found in milk or added during manufacturing The nal step is proteolysis the breakdown of proteins called caseins into peptides small protein fragments and amino acids This is performed by enzymes found in the milk and by microorganisms from the starter and found naturally in milk Milk Selection The rst step in making cheese and the one that has the greatest in uence on its classi cation is choosing the appropriate milk The amount of fat found in cheese is determined by the type of milk from which it is made Whole reducedfat 2 percent or fatfree nonfat milk buttermilk cream whey milk solids notfat MSNF or any combination of these can serve as the basis for cheese making Homogenized milk is usually selected for making soft cheese because homogenization makes the casein proteins coagulate more easily and the increased surface area of the brokenup fat results in a moister product Cheese Production Liquid Portion Whey Milk Enzyme ie rennin rennet gt or gt Acid Choices Direct acid added Indirect acidic environment created by adding bacterial cultures Solid Portion Cheese Curd Enzyme versus Acid Coagulation what s the difference Enzymes that are used to coagulate the casein and produce cheese produce a calcium rich thick tough rubbery texture Acids produce a less calcium concentration in the curd and produces a very small fragile curd Enzyme Coagulation The enzyme most commonly used to coagulate milk in cheese making is rennin obtained from milkfed calves speci cally their fourth stomach Rennin also called chymosin is sold commercially as rennet Other sources of available rennin include cows pigs plant sources and genetically engineered bacteria Acid Coagulation There are two methods by which acid may be used to coagulate milk proteins and thus form cheese The rst method is simply to add acid directly to the milk The second and more complex method is to inoculate the milk with a bacterial starter culture that acidi es the milk by converting lactose milk sugar to lactic acid Curd Treatment Cutting Slicing the curd increases its surface area Sometimes the curd is placed on strainers to remove even more whey Heating This encourages the evaporation of whey which allows lactic acid to build up to create a rmer more elastic texture Heat also destroys certain undesirable microorganisms After heating the curds are washed with cold water to produce softer highermoisture cheeses 3 Salting Salt controls the growth of bacteria and further dehydrates the curd It also contributes to the avor texture and appearance of cheese The two major types of salting are dry salting and brine salting Two factors in uencing salting are pH and temperature more salt is absorbed at a lower pH and higher temperature Salted cheeses have a nal salt concentration averaging 05 2 percent Knitting Some cheeses are knitted that is the curd is united or melted into a solid mass through the use of heat Pressing Pressing is another way to create a solid mass out of the curd and the last step before ripening Curds are physically pressed into compact masses by placing them in boxes or other containers under pressure Cheeses Bacterial Ripened Internal Cheddar Colby Edam Gouda Gruyere Parmesan Provolone Romano Swiss External Bel Paese Brick Liederkranz Limburger Monterey Jack Muenster Port du Salut Trappist Mold Ripened Internal Blue Gorgonzola Roguefort Stilton External Brie Camembert Why are cheddar cheeses labeled mild medium or sharp Like wine the nished character of these cheeses is determined not only by the original ingredients but by the maturation process The avor of cheddar cheese can range from mild to sharp depending on the duration of aging Although the time cheddar is held for aging varies by the cheese company the general guideline is that mild cheddar is aged for at least 60 days medium for 3 to 6 months sharp for a minimum of 9 months and extra sharp for at least 15 months Whey and Whey Products Whey separated from its water content is low in fat and rich in nutrients It contains the water soluble whey proteins and most of the lactose water soluble vitamins and minerals of the milk Whey is highly perishable when fresh so it is most often processed quickly into whey cheeses dry whey and modi ed whey products Sweet whey results from coagulating milk with rennin whereas acid whey originates from acid coagulated milk Besides having greater acidity acid whey also contains higher mineral concentrations because the acid releases the calcium from the casein molecule causing it to be dispersed in the whey portion Process processed cheese A cheese made from blending one or more varieties of cheese with or without heat and miXing the result with other ingredients Natural Cheese Grind blend heat pasteurize emulsi er Process Cheese ie American milk andor whey solids gt Process Cheese Food moisture optional additions milk solids sweetening agents starch vegetable gums Process Cheese Spread Imitation Cheese Cheese analogues or imitation cheeses are cheeselike products in which the milk fat in natural cheese has been replaced with vegetable oil These analogues are less eXpensive than natural cheese and are manufactured using a process similar to that used to make process cheese Milk proteins such as calcium caseinate are mixed with a small amount of vegetable fat water salt emulsifiers and lactic acid before being heated to pasteurization temperatures for several minutes The liquid is then poured into molds or formed into slices The texture avor and melting properties of imitation cheeses are similar to those of process cheese Nutritionally these analogues are lower in cholesterol and sodium but equivalent in fat although it is less saturated than that from natural cheese Selected Food Additives in Cheeses Unprocessed Cheese Typical Ingredients Milk salt enzymes annatto natamycin other additives appearing less frequently are gums powdered cellulose potato starch corn starch calcium sulfate or potassium sorbate Process Processed Cheese Typical Ingredients Milk water whey milk fat milk protein concentrate whey protein concentrate sodium phosphate calcium phosphate lactic acid sorbic acid sodium alginate enzymes apocarotenal annatto cheese culture process cheese food or spreads that come packed in a jar or can often contain canola oil as one of the major ingredients and sugar as a sweetener Food Additive in Cheese Annatto A natural color often added to cheddar cheeses Apocarotenal Natural orange carrotlike color Calcium phosphate To improve texture consistency and spreadability of process processed cheese products Calcium sulfate Acts as a desiccant substance that absorbs water to prevent caking in shredded cheese Avoid if sensitive to sul tes Cheese culture Bacteria added to produce cheese Enzymes Natural enzymes used to produce cheese Gums carageenan guar gum locust bean gum and xanthan gumThickening stabilizers derived from plants that provide a cohesive rubbery texture Lactic acid option acetic acid Which is vinegar Used for pH control avor and as a preservative because many bacteria are inhibited by low acidity Milk fat Natural ingredient adding avor and smooth mouthfeel Milk protein concentrate Natural ingredient adding protein Natamycin Mold inhibitor Potassium sorbate Preservative that inhibits molds Sodium alginate Extracted from seaweed used to stabilize and thicken Sodium phosphate Emulsifying gelling stabilizing thickening Sorbic acid Preservative that inhibits fungi Starch potato starch corn starch cellulose Plant products that prevent caking of shredded cheese Whey Natural ingredient adding protein and lactose Whey protein concentrate Natural ingredient adding protein Purchasing Cheese Cheddar Cheese US Grade AA Fine highly pleasing cheddar avor smooth compact texture uniform color 6 US Grade A Pleasing avor smooth compact texture but may have a few openings or curdy appearance uniform color with possible white lines US Grade B Fairly pleasing avor but may contain certain undesirable avors to a limited degree texture may have several defects mealy coarse crumbly corky etc color may possess several undesirable characteristics dull faded salt spots molded etc US Grade C May possess somewhat objectionable avors and colors texture may be loose and color may be slightly bleached on the surface Food Preparation with Cheese Cheese can be consumed as is or as an ingredient in casseroles pizza souf s soups salads omelets eggs and other dishes The cheese selected for preparing a particular food depends on its functional factors of shredability meltability oiling off blistering browning and stretchability Ripened cheeses heat better than soft cheeses Temperatures should be kept low and heating times for cheeses should be short Storage of Cheese Most cheeses are best refrigerated in their original wrappers Freezing is not recommended for soft highwatercontent cheeses but hard cheeses can be frozen for up to 2 months Process cheese spreads packaged in jars are commonly stored on a cupboard shelf at room temperature for up to 4 months but once opened they must be refrigerated Chapter 7 Protein Overview Sources gt Animal products f1sh seafood gt Plant Sources legumes and beans gt Plant proteins are lower in quality due to differences in amino acid composition Function in Foods gt Hydration gt Denaturation gt Enzyme reactions gt Browning gt Buffering Lipid Overview Sources gt Animal products including dairy gt Plant sources include nuts seeds avocados olives coconuts vegetablebased oils Function in Foods gtHeat transfer during food prep gt Aid in tenderization gt Texture gtFlavor Types of Meat Beef cuts originate from cattle which are classi ed according to age and gender Veal cuts originate from young calves of beef cattle slaughtered between 3 weeks to 3 months Lamb and mutton are the meat of sheep Pork cuts are derived from young swine of either gender slaughtered between 57 months of age Composition of Meat Meat is composed of water muscle connective tissue and adipose tissue fatty all of which in uence meat texture Marbling term used to describe fat embedded within the muscles Maj or determinant of the quality and thus the price of meat Why is marbling desirable When meat is cooked the intramuscular fat deposits melt and contribute to perceived avor and juiciness For this reason the more marbling in a cut of beef the higher the grade Animal s age diet and species affect the texture of the fat Muscle Tissue Most of the protein in animals is found in their muscles which serve as the main sources of dietary meat The characteristics of muscles are an important consideration in deciding how the resulting meat should be prepared Muscles are made up of a collection of individual muscle cells called muscle bers that are each surrounded by an outer membrane called the sarcolemma Composition of Muscle Actin thin lament protein Myosin thick lament protein Actinomyosin contracting muscle results in crosslinking of A amp M Protein responsible for muscle movement Adenosine triphosphate ATP A universal energy compound in cells obtained from the metabolism of carbohydrate fat or protein The energy of ATP which is located in highenergy phosphate bonds fuels chemical work at the cellular levelComposition of Connective Tissue Composition of Connective Tissue Composed of protein matrix that holds muscle cells together Type and amount of CT determines tenderness and type of cooking method Collagen tough brous matrix that converts to gelatin upon exposure to heat Increased amount in muscles for locomotion Increased amount in older animals Elastin rubbery elastic matrix that does not soften upon cooking Found primarily in ligaments and tendons Adipose Fatty Tissue Adipose tissue is simply fat which serves as insulation under the skin subcutaneous and as padding in the abdominal cavity for sensitive internal organs When it appears on the outside of meat this fat is known as cover fat Fat Color and Texture The animal s age diet and species affect the color and texture of fat It is white in younger animals and turns progressively more yellow as the animals age because of the presence of carotenoid pigments in the feed Bone Bones are used as landmarks for identifying the various meat cuts from a carcass When buying meat keep in mind that bone weighs more than meat and that the higher the proportion of bone there is to meat the less the meat yield and the more the cost of the edible portion will be Marrow Marrow is the soft fatty material in the center of most large bones The marrow found within the bone will generally be of two different types 1 yellow marrow found in the long bones and 2 red marrow red because it is supplied with many blood vessels in the spongy center of other bones Antibiotic Resistance Bacteria and other microorganisms can develop antibiotic resistance the ability to survive in the presence of a medication that once killed them Antibiotic resistance can develop sporadically due to a genetic mutation or can be a process of adaptation to the constant presence of an antibiotic or disinfectants Superbugs in Food Clostridium difficile commonly called C diff is a bacteria most commonly associated with diarrhea in hospitalized patients While C diff causes only mild diarrhea in some patients others develop recurring severe diarrhea that requires the use of powerful antibiotics Infection with C diff is often attributed to antibiotic use antibiotics kill off the normal bacteria in the gut allowing overgrowth of C diff C diff has recently been identified in commercial meat Color Chemistry of Red Meat Color of muscle is derived from pigmentcontaining proteins primarily myoglobin MYOGLOBIN Ironcontaining protein that binds 02 in muscle HEME ironcontaining portion of myoglobin Meat Pigments Each pigmentcontaining compound in meat consists of two parts a protein globin and a nonprotein pigment heme The heme is an atom of iron surrounded by four connecting pyrrole rings The difference between myoglobin and hemoglobin is that the simpler myoglobin molecule consists of one protein polymer strand and one heme molecular weight 5 about 17000 whereas the larger hemoglobin molecule is made of four protein polymer strands and four hemes molecular weight 5 about 68000 Composition of Meat Pigments Myoglobin purplered Oxymyoglobin bright red desired color of retail meats I Results from exposure of myoglobin 02 Metmyoglobin brownred prolonged exposure to oxygen or bacterial in uence causes uncooked meat to brown Extractives Flavor compounds consisting of nonprotein nitrogen substances that are end products of protein metabolism PURCHASING MEATS To ensure that consumers are purchasing meat that is safe federal laws require the inspection of animal carcasses In addition to this mandatory inspection for safety meat may also be assigned yield grades and then later quality grades to assist consumers in selection Meat processors submit to the grading system voluntarily Grading The grading of meat is not under government mandate or control but is a strictly voluntary procedure that the meat packer or distributor may have done under contract with the USDA For purposes of grading a cut is made between the twelfth and thirteenth rib in order to expose the rib muscle Quality grades The USDA standards for beef veal lamb and mutton Nutrient Content Meat consists primarily of water 75 protein 20 and fat varies with a few minerals and some B vitamins It contains very little to no carbohydrates liver is the richest source no ber and no vitamin C In uence of Fat Content on Grading Fat especially in the form of marbling melts during heating thereby increasing the avor and perceived tenderness of the meat USDA quality grades of beef re ect this marbling Prime the top USDA grade contains the most marbling and is the most expensive If the fat is yellowish the meat may be from an older animal and therefore may be tough Beef USDA Quality Grades There are eight USDA quality grades for beef with the top three Prime Choice and Select being of most concern to consumers Choice and Select are the grades most commonly purchased by consumers in the supermarket Standard and Commercial USDA grades are not seen at the retail level because they are usually from older more mature and therefore less tender cattle USDA grades identi ed as Utility Cutter and Canner are usually used in processed foods such as canned meats sausages and pet foods USDA Prime Very tender juicy avorful the greatest degree of marbling The most expensive of the grades Prime is sold to ner restaurants and some meat stores For marbling Very heavy marbling that looks like snow akes and is evenly distributed USDA Choice Quite tender and juicy good avor slightly less marbling than Prime The grade most frequently found in retail stores For marbling moderate marbling in delicate lacy streaks that is less evenly distributed than in Prime USDA Select Fairly tender not as juicy and avorful as Prime and Choice has least marbling of the three and is generally lower in price For marbling spotty marbling scattered like rice grains Determinates of T ENDERNESS Cut of meat Animal s age Heredity and breed characteristics Diet Marbling Type of aging or electrical stimulation of meat In uence of Preparation how you prepare that cut of meat is the nal and most signi cant factor of determining tenderness on a consumer level Did we use a marinade Moist or dry heat Add salt increase the saliva production Use a meat mallet Cuts of Beef Retail cuts differ from region to region but all cuts originate as primal cuts Primal cuts are divided into workable portions called subprimal cuts Subprimal cuts can be sold for retail sale or cut into individual fabricated cuts for retail sale Example Short Loin gt Strip Loin gt New York Strip Steak Aging Meats Rigor Mortis and its Impact on Tenderness gt What is it postmortem physical and biochemical event resulting in crosslinking of actin and myosin causing muscle tissues to contract and stiffen gtWhy is it important to allow rigor to resolve and meat to age By allowing meats to age under specific environmental conditions natural enzymes within meat begin to break down and tenderize protein molecules gtAging Meats FAQs When does it take place After slaughter prior to retail sale Why is it important Improves tenderness moisture content avor color and ability to brown during cooking Are all meats aged Primarily pertains to beef due to older age at time of slaughter and increased activity of these animals during their lifetime What is the in uence of age and activity on tenderness The greater the age the less tender the animal or protein cuts The greater the activity the more tender the meat will be Rigor Mortis Within 6 to 24 hours after slaughter the muscles of livestock enter the state of rigor mortis This condition reverses naturally I or 2 days after slaughter The way that meat is handled during this period is important because it can affect pH which in uences meat quality The perception of a meat s juiciness or dryness depends on the binding of water to muscle proteins and this is in uenced by pH Waterholding capacity is best in meats with a pH of 58 44 A pH that is too low or too high results in less than desirable meat Meat pH changes during rigor mortis because the oxygendeprived cells switch to glycogen as an energy source Glycogen is converted to lactic acid and the increase in acidity causes the pH to fall from approximately 70 to 58 which is a desirable pH for meat quality Slaughtering Conditions Both the conditions preceding slaughter and the handling of the carcass immediately afterward can result in several problems affecting the meat s quality poor quality darkcutting beef pale soft and exudative PSE pork thaw rigor cold shortening and green meat The rst three problems are all related to pH Poor Quality A poorquality meat will result if all the glycogen has already been converted to lactic acid prior to slaughter This causes the pH to drop too low and occurs when the animal has already used up all of its glycogen as a result of stress from fear fasting temperature extremes andor exercising Darkcutting beef If glycogen stores are depleted before death because the animal is exercised or stressed insuf cient lactic acid will be produced during rigor mortis The resulting higher pH above 58 of the meat will result in a deeppurple brown meat known as darkcutting beef which has a sticky texture that is unacceptable to consumers PSE pork Pale soft and exudative PSE pork results if the pH drops too low causing the meat to become very dry when cooked A low pH under 51 or even up to 54 can cause the pork to become extremely pale mushy slimy avorless and full of excess drip Japanese export buyers evaluate pork based on its pH Because a low pH can damage meat proteins and alter color to a pale tan they watch for this color change and select darkercolored meats with a higher pH and thus better avor Some meat packing companies even measure the pH of their meat products Thaw rigor Freezing meat before it undergoes rigor mortis can cause thaw rigor a phenomenon in which the meat shrinks violently by almost 50 when thawed Cold shortening A kind of thaw rigor occurs although to a lesser degree when meat has been chilled too rapidly before rigor mortis called cold shortening In both cases the meat will be tougher Neither thaw rigor nor cold shortening meat is allowed to be sold at the consumer level Green meat Meat cooked while in a state of rigor mortis before the muscles have had time to relax will be tough and tasteless However it can be quite tender if prepared before stiffening begins Rigor mortis From the Latin for stiffness of death the temporary stiff state following death as muscles contract The passing of rigor occurs when the muscles gradually extend again This is facilitated by the proteases that hydrolyze proteins and disrupt the Z bands As a result the actin and myosin release from each other causing the muscles to relax Aging Holding meat after slaughter to improve texture and tenderness A ripening that occurs when carcasses are hung in refrigeration units for longer periods than that required for the reversal of rigor mortis Dry aging Carcasses are hung in refrigeration units at 34 F 38 F l C to 3 C with low 70 to 75 or high 85 to 90 humidity for l to 6 weeks Fast or we aging Most beef is aged in plastic shrinkwrap Warmer temperatures of 70 F 21 C with a high humidity of 85 to 90 lower the aging time to 2 days but additional aging will occur during the 10 or so days it takes the meat to reach the consumer Vacuumpacked aging Less weight loss and spoilage occur in meats that are aged by vacuum packing cryovacing During this process meat carcasses are divided into smaller cuts vacuum packed in moisture and vaporproof plastic bags and then aged under refrigeration Why does a carcass stiffen Rigor mortis is caused by a cascade of events that take place at the cellular level Death interrupts the blood ow and prevents oxygen from reaching the cells Changes then occur within the cells of the muscles causing them to contract and stiffen Muscles stay relaxed in the presence of ATP adenosine triphosphate but once it is used up through glycolysis the lack of ATP causes actin to bind irreversibly with myosin The muscles then contract This rigidity of the muscles in rigor mortis occurs because the crosslinks between the actin and myosin laments overlap and cause the sarcomeres to shorten The automatic contraction of brils in the muscle cells causes the characteristic muscle stiffness Artificial Tenderization Enzymes relax and breakdown muscle proteins Examples plant sources Salts aid in moisture retention and ions of Na K Mg help break down protein components Examples sauces spices rubs Acids assist in breaking down proteins allowing avors to penetrate Example vinegar wine lemon tomato and other fruit juices Mechanical Tenderization denature proteins Methods include grinding cubing needling and pounding These actions physically break the muscle cells and connective tissue making the meat easier to chew Grinding and cubing meat simply increase the surfaceareatovolume ratio causing the teeth to have less work to do Needling uses a special piece of equipment to send numerous needlelike blades into the meat separating the tissues Electrical Stimulation increases enzyme activity How Do Meat Tenderizers Work Meat tenderizers contain enzymes that break down muscle proteins They are sprinkled on meat which is then pierced with a fork to drive the enzymes below the surface where they hydrolyze muscle cell proteins and connective tissue when activated by the heat of preparation Inspection Mandatory Process Determines wholesomeness diseasefree Mandatory USDAFSIS Antemortem live inspection for signs of disease Postmortem inspection includes muscle inspection for disease Processed Meats About one third of all meat is processed meaning it has been changed from its original fresh cut Ham sausage and bacon are the most popular processed meat products Other examples of processed meats include salami bologna bratwurst and pastrami Curing Commonly cured meat products include ham bacon sausages frankfurters corned beef and luncheon meats The term cured today is generally used to mean the addition of synthetic nitrates or nitrites salt and other preservatives This mixture often includes sodium or potassium nitrate sugar spices phosphates dextrose corn syrup lactates and seasonings Dry curing consists of mixing the ingredients together and rubbing them into the surface of the meat so that they can penetrate their way to the center Another method involves brining the meat soaking it in a salt solution or immersing it in a pickling solution Salt and other avors migrate into the meat making it more avorful Osmosis is the mechanism whereby uids diffuse through cells into the meat to equalize the increased salt ion concentration The greater salt concentration in the meat causes it to absorb some of the water of the brining solution 6 to 8 of the meat s original weight resulting in a moister meat The most common commercial curing technique is one in which the curing solution is mechanically pumped or injected into the meat using a machine lined with needles These injected curing solutions increase the meat s weight If the meats are not shrunk back to their original weight through heating andor smoking and if they contain up to 10 added moisture they must be labeled Water Added Smoking Most cured meats are also smoked and cooked Smoke imparts avor aroma and color to foods Meats are placed in smokers where they are exposed to the smoke of burning wood In smoke houses the intensity of the smoke the humidity and the temperature are all carefully regulated and the type of sawdust or wood used to produce the smoke determines the product s resulting avor Sawdust is the most economical fuel and is oft en used by commercial processors but other woods available for smoking include mesquite hickory oak apple and various combinations of them Canning Canned meats are processed through either pasteurization or sterilization Pasteurized canned meats require refrigeration and are labeled Perishable Keep Refrigerated whereas those that are sterilized do not need refrigeration as long as the can remains sealed Drying is not widely used for meats but it has some applications for them Certain types of sausage including pepperoni salami and cervelat are dried They are cooked sometimes smoked and dried under specific conditions of humidity and temperature How does nitrite cure meat Nitrite or nitrate salts are used in most cured meat products When added to meat the nitrite molecule N02 chemically reacts with the meat to create nitric oxide which is the agent responsible for curing the meat Nitrate NO3 will not cure meat until it is converted to nitrite this can be accomplished before or after it is added to the meat 10 Food Additives in Processed Meats Nitrite is a common food additive used by the food industry to keep processed meat from turning brown Nitrite and salts of nitrate are used as a preservative in approximately 7 of foods particularly processed meats such as ham hot dogs bacon sausage bologna salami and other cold cuts These food additives are responsible for keeping many packaged processed meats permanently pink while simultaneously reducing the risk of botulism and creating a distinctive avor Selected additives used in processed meat and poultry products Butylated Hydroxytoluene BHT Butylated Hydroxyanisole BHA Tocopherols Vitamin E antioxidants that help maintain the appeal and wholesome qualities of food by retarding rancidity in fats sausages and dried meats Carrageenan seaweed is the source of this additive that may be used as a binder in meat products Citric Acid widely distributed in nature in both plants and animals It can be used as an additive to protect the fresh color of meat cuts during storage Citric acid also helps protect avor and increases the effectiveness of antioxidants Corn Syrup sugar that is derived from the hydrolysis of cornstarch Uses include avoring agent and sweetener in meat and poultry products Emulsi er substance added to products such as meat spreads to prevent separation of product components to ensure consistency Examples of these types of additives include lecithin and mono and diglycerides Gelatin thickener from collagen that is derived from the skin tendons ligaments or bones of livestock It may be used in canned hams or jellied meat products Humectant substance added to foods to help retain moisture and soft texture An example is glycerin which may be used in dried meat snacks Monosodium Glutamate MSG MSG is a avor enhancer It comes from a common amino acid glutamic acid and must be declared as monosodium glutamate on meat and poultry labels 11 Phosphates the two bene cial effects of phosphates in meat and poultry products are moisture retention and avor protection An example is the use of phosphates in the curing of ham in which approved additives are sodium or potassium salts of tripolyphosphate hexametaphosphate acid pyrophosphate or orthophosphates declared as phosphates on labels Propyl Gallate used as an antioxidant to prevent rancidity in products such as rendered fats or pork sausage It can be used in combination with antioxidants such as BHA and BHT Sodium Caseinate used as a binder in products such as frankfurters and stews Sodium Erythorbate the sodium salt of erythorbic acid a highly re ned foodgrade chemical closely related to vitamin C synthesized from sugar and used as a color xative in preparing cured meats Sodium Nitrite used alone or in conjunction with sodium nitrate as a color xative in cured meat and poultry products bologna hot dogs bacon Helps prevent growth of Clostridium botulinum which can cause botulism in humans Whey Dried the dried form of a component of milk that remains after cheese making Can be used as a binder or extender in various meat products such as sausage and stews Natural curing is sometimes used to refer to the use of microbes typically bacteria to convert nitrates in the environment to nitrites which then react with meat to cure it For example the addition of harmless foodgrade microorganisms and sea salt to meat can result in a natural curing process Examples of other additives considered as natural curing agents include carrageenan seaweed sodium bicarbonate baking soda vegetable and fruit juices vinegar honey sugar food start cultures and spices When meat is packaged and labeled as natural this term refers to the additives in the product not the meat itself This is because all meat is considered natural irrespective of the antibiotics or hormones used in raising the animals Types of Processed Meat Ham is cured pork and according to USDA standards only meat from the hind leg of a hog can be labeled ham Canned ham Boneless fully cooked ham that can be served cold or heated Most are cooked only to pasteurization temperatures so they must be refrigerated Sterilized hams are usually available only in cans of under 3 pounds 12 Wateradded ham Contains no more than 10 by weight of water added The added moisture contributes to a moist juicy and tender texture Imitation ham Ham that retains more than 10 moisture after curing Country ham Ham cured by the dry salt method and usually hickory smoked to develop a distinctive avor Picnic ham Cured pork that comes from the front leg instead of back leg of the hog and therefore cannot be labeled simply ham This cut is less tender and higher in fat than regular ham Bacon is cured and smoked meat from the side of a hog It should be balanced in its proportion of fat to lean When cooked bacon with too much lean will be less tender whereas bacon with too high a proportion of fat will shrink too much Sausage originated in the Mediterranean It is meat that has been finely chopped or ground and blended with various ingredients seasonings and spices The seasonings usually include a curing salt which is partly responsible for the distinctive avor There are four major classifications of sausage Uncooked Made from ground uncooked meat Fresh pork sausage bratwurst mettwurst and bockwurst are examples Uncooked fresh sausage has the highest moisture content approximately 50 60 Fresh sausage can be stored for several days and requires cooking before ingestion Raw fermented Raw fermented sausage is kept at high temperatures allowing the growth of bacteria These bacteria produce lactic acid which lowers the pH of the sausage Examples of this type of sausage include merguez and Lebanon bologna which is smoked Raw fermented sausage must be cooked before eating Cooked Made from cured meat which may be slightly smoked before being stuffed into the casings Examples include hot dogs bologna and knockwurst Drysemidry Made of cured meat that has been dried Dry fermented sausage is thought to have originated in Italy in the early 18th century Examples are pepperoni salami thuringer and cervelat Dried cured sausage undergoes a ripening period in which the texture changes from a soft pliable mass into a hard sliceable distinctly avored sausage LowerFat Processed Meats Many processed meats contain 30 to 50 fat Consumers have challenged processed meat product manufacturers by demanding foods that are lower in fat and cholesterol Many processed meats are available in versions that are 295 fatfree 13 They are produced by using leaner cuts of meat adding more water andor including ingredients such as ber gums modi ed starches and whey protein concentrate Water can be substituted for fat in processed meats as long as the total amount of fat and water does not exceed 40 with a maximum fat content of 30 Mechanically Deboned Meat The traces of meat that are left on the bones after butchering can be collected and sold as mechanically deboned meat This is accomplished by grinding the remaining meat and bones together and removing the bone by putting the mixture through a sieve The resulting meat contains ground bone bone marrow and soft tissue and is most commonly used in further processed meat products Restructured Meat Restructured or fabricated meat is made from meat trimmings and or lowergrade carcasses It is similar to real meat in texture avor and appearance but is less expensive Storage and Preparation Meat is a PHF potentially hazardous food because of its high protein and high water content ShelfLife lowtemperature storage for short duration Refrigerated meats should be consumed wi 3 to 4 days The exception to this guideline is always meat that has been ground Meat that has been ground undergoes oxidation faster because of the greater amount of surface area Frozen meats can be stored for up to 6 months if properly wrapped Changes During HeatingTenderness and Juiciness Cooking meats at the correct temperature for the right amount of time will maximize their tenderness juiciness and avor Although heat makes meat more palatable exposing it to high temperatures for too long will toughen shrink and harden meat because such exposure shortens muscle fibers denatures proteins and causes the meat to dehydrate Searing Cooking that exposes a meat cut to very high initial temperatures this is intended to seal the pores increase avor and enhance color by browning To sear a piece of meat place the meat a pan that is already extremely hot and leave it in the pan long enough for it to form a rich brown crust Blanching Another technique thought to lock in the juices is blanching Meat is blanched by boiling it very brie y but this method is no longer recommended because watersoluble 14 compounds such as vitamins minerals and avor substances may be lost In the end proponents argue that neither blanching nor searing makes any difference in moisture loss in meats exposed to prolonged heating Larding Inserting strips of bacon salt pork or other fat into slits in the meat with a large needle Barding Tying thin sheets of fat or bacon over lean meat to keep the meat moist during roasting The sheets of fat are oft en removed before serving Effect of Temperature on Meat Components Meat becomes tender when cooked due to breakdown of its protein fat and connective tissue with increasing temperatures 1000 F Proteins begin to unfold the meat appears red soft and slippery 1200 F Proteins coagulate clump together and loose water the meat appears very firm and pink 1400 F Connective tissue shrinks more moisture is lost the meat appears pinkishbrown and visibly loses juices 1500 F Connective tissue begins dissolving into a gelatinlike substance and proteins are densely packed meat appears brown and shrunken and starts to taste tough 1700 F Proteins are entirely coagulated and most of the moisture is lost meat tastes hard and dry Flavor Changes Natural compounds in meat yield that characteristic meat avor but other factors contribute to avor as well including protein coagulation melting and breakdown of fats organic acids and nitrogencontaining compounds WarmedOver Meat Flavor The warmedover avor in reheated meat is thought to be caused by the oxidation of the meat s unsaturated fatty acids which results in various off avor substances e g hexanal Warmed over avor is just one example of lipid oxidation thought to be the major cause of quality deterioration in meats Flavor Enhancements 15 The avor of baked or broiled meat can be enhanced by basting and seasoning If the seasoning includes salt however some professional chefs recommend adding it only after the meat has been slightly browned because salt draws out juices and retards browning Sauces for beef Au Jus natural beef juices Beamaise thick sauce of egg yolks white wine tarragon Vinegar herbs Bechamel seasoned white sauce Bercy Butter shallots cooked in white wine mixed with creamed butter and parsley Beurre Noir clari ed butter with Vinegar or lemon juice Bordelaise brown sauce with red wine shallots or green onions herbs and lemon juice Brown Sauce Espagnole avorful beef sauce used as baste for others Chasseur brown sauce with mushrooms tomato sauce tarragon Chili Salsa chopped tomato onion green chili pepper Choron beamaise sauce and tomato Colbert beamaise sauce and meat glaze Hollandaise thick sauce of egg yolks melted butter and lemon juice Madeira brown sauce and Madeira wine Maitre d Hotel Sauce bechamel sauce with butter lemon juice parsley and tarragon Marchand de Vin red wine parsley green onions and lemon juice Meuniere browned butter with lemon juice and parsley Momay creamy cheese sauce 16 Perigueux wine sauce with diced truf es Robert brown sauce with mustard onion tomato and pickle Determining Doneness Doneness of some cuts such as steaks or chops can be determined by color and touch Rare strong red interior spongy texture 136 F 140 F Medium pink interior springy to slightly rm texture 160 F 167 F WellDone brown interior rm texture moist but not juicy 172 180 F Accurate determination of doneness for roasts or large cuts of meat requires the use of a thermometer inserted in the thickest portion Temperature is the best determinant of doneness Touch as a test for doneness Rare Shake dangle and relax right hand pressing the area between thumb and index nger feels similar to rare steak soft and yielding to slight pressure Medium Stretch out the right hand and tense the ngers the springy rmness is similar to the resistance felt in mediumcooked meats Well done Harden the right hand into a tight ball this hard and unyielding feeling with all the springiness gone is how welldone meat feels Four lb roast purchased and after roasting cooked wt 3lb 12 lb drip in drip pan Compute Yield Drip amp Evap Yield amp Cooking Loss Yield Cooked wt x100 3 X100 75 Raw Wt 4 Drip Drip wt x100 05 x100 125 Raw Wt 4 Evaporation Raw wt Cooked wtDrip wt x100 Raw Wt 4 305 x 100125 17 Total Cooking Loss Raw wt Cooked wt X 100 Raw wt 4 3 x10025 4 Roasting Roasting is the heating of moderatetolarge tender cuts of meat in the dry hot air of an oven A roast will usually be at least 2 12 inches thick and provide more than three servings Th e meat is placed fat side up if it has any on a rack in an open pan The rack prevents the meat from sitting in its own juices which would cause the meat to simmer rather than to roast Temperatures from 300 F 350 F 149 C 177 C are recommended for roasting and should produce an evenly cooked easy to carve juicy tender avorful roast with a greater yield than roasting at higher temperatures would have produced Broiling and Grilling Smaller cuts of tender meat ranging from 1 to 3 inches in thickness can be broiled High temperatures and short heating times keep the meat tender Broiling and grilling times are based primarily on the meat s thickness and its distance from the heat The goal in either broiling or grilling is to simultaneously heat the inside of the meat while achieving just the right degree of browning on the exterior PanBroiling 1 Place beef in preheated frying pan 2 Do not add oil or water Do not cover 3 Cook slowly 58 to 1 cuts turning occasionally For cuts thicker than 12 use medium to mediumlow heat For thinner cuts use mediumhigh heat 4 Pour off excess drippings as they accumulate 5 Season if desired Frying Saut ing panfrying and deepfrying are suitable for tender small pieces of meat that are low in fat or that have a breaded coating Saut ing Saut ing is identical to panbroiling except that a small amount of fat is heated to the sizzling 18 point before the meat is added Examples of sauteed meat dishes include liver and onions veal Oscar veal picatta and veal cordon bleu PanFrying In panfrying more fat but no more than up to 12 inch deep lower heating temperatures and longer cooking times are used than what is common in sauteing Typically panfried meat cuts are larger and include steaks chops and sliced pieces of liver DeepFrying Meat with the exception of chickenfried steak is seldom deepfried When it is the meat is usually cut into small pieces and dipped in seasoned our or cornstarch placed in a wire basket submerged in oil preheated to 300 F 36O F 149 C 182 C and heated until golden brown MoistHeat Preparation Braising consists of simmering meat in a covered pan in a small amount of water or other liquid It is ideal for less tender cuts such as beef chuck round steak and ank steak because braising breaks down collagen and tenderizes the meat Braising can transform a meat s texture from tough to forktender Simmering or Stewing Simmered or stewed meat is cooked completely submerged in liquid The pan is covered brought to simmering not boiling and cooked until the meat is tender Fricassees are stews in which the meat is first browned in fat Cured meats such as corned beef or tongue and fresh beef brisket cuts are commonly prepared by stewing Steaming Steaming exposes food directly to moist heat Meats can be steamed in a pressure cooker or in a tightly covered pan They can also be wrapped in aluminum foil or placed in a plastic oven bag which is then placed in a heated oven Microwaving Microwave ovens are usually not the best option for cooking meats except for thawing and reheating leftovers They decrease juiciness do not brown and do not heat sufficiently to kill pathogens such as Trichinella spiralis 19 Carving Meat should not be sliced in just any manner because the way it is sliced affects its tenderness The rst step in slicing meat is to determine the direction in which the muscle bers run called the grain This can be seen on the surface of the meat It may be dif cult to nd the grain in larger cuts such as roasts because they consist of parts of several different muscles each with its own grain STORAGE OF MEATS Refrigerated Meats are best refrigerated at just above freezing 32 F O C between 32 F and 36 F O C 2 C They do not freeze until the temperature drops to below 28 F 2 C The best place to store meats in the refrigerator is in the coldest part Wrapping Meat Most retail meats are packaged with plastic wrap and can be refrigerated in their original wrap for up to 2 days After that time the store wrapping should be removed and replaced by loosely wrapped plastic wrap wax paper or aluminum foil Leaving the tight store wrapping on meat for more than 2 days creates moist surfaces which promote bacterial growth and deterioration of the meat Exceptions to this general storage guideline are hams and other processed meats that are high in salt They should not be stored in aluminum foil because the salt s corrosive action on aluminum foil will cause discoloration of the meat Refrigeration Times General guidelines suggest that fresh meat should not be stored in the refrigerator longer than 3 to 5 days and that ground meats and variety meats should be cooked within 1 or 2 days ControlledAtmosphere Packaging One alternative to storing meats for long periods of time at refrigeration temperatures is a patented controlled atmosphere package CAP available only to meat wholesalers It can extend the shelf life of fresh red meat from the current 2 days to up to 28 days The process involves using a special package that allows the removal of oxygen and its replacement with a mixture of 70 nitrogen and 30 carbon dioxide Frozen 20 Meats to be frozen should be wrapped tightly in aluminum foil heavy plastic bags or freezer paper and stored at or below 0 F 18 C Wrapping meat for freezing apothecary or drugstore method 1 Place the meat near the center of the wrap Bring edges of the wrap together over the meat 2 Fold the wrap over once then repeat folds until the last fold is tight against the meat 3 Make top folds even Smooth the ends close to the meat and fold into triangles 4 Fold the ends under the package away from the top fold to tighten it 5 Seal with freezer tape 6 Label with date kind of meat and number of serVings or weight 21
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