HNF 300 Exam 2 Study Guide
HNF 300 Exam 2 Study Guide 300
Popular in Experimental Approaches to Food
verified elite notetaker
KIN202 Wesley Smith Applied Nutrition for Health & Performance
verified elite notetaker
Mariana de la Maza
verified elite notetaker
Popular in Nursing and Health Sciences
verified elite notetaker
This 20 page Study Guide was uploaded by Courtney Moore on Friday August 7, 2015. The Study Guide belongs to 300 at Michigan State University taught by Nettles in Fall 2014. Since its upload, it has received 804 views. For similar materials see Experimental Approaches to Food in Nursing and Health Sciences at Michigan State University.
Reviews for HNF 300 Exam 2 Study Guide
Report this Material
What is Karma?
Karma is the currency of StudySoup.
You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!
Date Created: 08/07/15
HNF 300 F14 Exam 2 Ch 9 11 12 13 14 20 and 21 Review Chapter 9 1 The chemical composition of food can be determined in the laboratory List the major components and the minor components that are present in foods 0 Major Components Water Carbohydrates Proteins and fats 0 Minor Components Minerals vitamins acids flavor and pigment substances 2 Give examples of foods that are high intermediate and limited in water content Explain what is meant by water activity 0 Foods high in water include fresh fruits and vegetables milk oatmeal and eggs 0 Intermediate foods include Ice cream meats pizza cheese and bread 0 Foods low in water include crackers cookies peanuts popcorn 0 Water activity is measured on a scale of 00 to 10 water The more water bound a food is the lower the water activity will be Water activity is the ratio of vapor pressure of water in a food at a specified temperature to the vapor pressure of pure water at the same temperature 3 Describe four or five important functions of water in food preparation 0 Water is a universal solvent heat transfer freezing cleansing agent and promotes chemical changes 4 What is the pH scale What does it indicate Place several common foods on the scale 0 The pH scale is the degree of acidity or alkalinity on a scale of 1 to 14 Water has a pH of 7 Limes have a pH of 2 while egg whites have a pH of 9 5 Describe some unique characteristics of the water molecule 0 Water is polar and has a positive and negative end of the molecule 6 Name two types of hard water and the types of mineral salts contained in each 0 Temporary hard water contains calcium magnesium and iron bicarbonates o Permanently hard water contains calcium magnesium and iron sulfates 7 Describe two methods of softening permanently hard water 0 Method 1 use water softening agents such as washing soda and polyphosphates to precipitate the calcium and magnesium salts 0 Method 2 Use ion exchange process in which calcium and magnesium ions are exchanged for sodium ions 8 What are carbohydrates Simple carbohydrates Complex carbohydrates 0 Molecules made up of Carbon hydrogen and oxygen Simple carbohydrates are those derived from sugars molecules while complex carbs are starch and fiber 9 In the following list indicate which carbohydrates are monosaccharides disaccharides and which are polysaccharides Monosaccharides Disaccharides Polvsaccharides Glucose Sucrose Cellulose Fructose Maltose 10 11 12 13 14 15 16 17 18 Galactose Lactose Identify the monosaccharides building blocks for each disaccharide and polysaccharide listed in the previous question Disaccharides o 1 glucose 1 fructose 1 sucrose 0 1 glucose 1 galactose 1 lactose o 2 glucose 1 maltose Polysaccharides 0 40 monosaccharides linked together What are oligosaccharides Give examples 0 They are carbs not broken down my humans and made up of 10 or fewer linkages Examples include Raffinose and Stachyose Give several examples of vegetable gums and describe some of their uses in food processing 0 Vegetable gums are polysaccharides that act as a thickener or gelling agent in foods In food processing they thicken food or build texture in order to improve mouthfeel along with stabilizing solids in water Gums help retain water reduce evaporation rates modify ice crystal formation and produce other desired changes in consistency Name two fractions of starch and describe the major differences in their chemical structures 0 One is a long chain or linear type of molecule called amylose o The other is a highly branched bushy type of molecule called amylopectin List at least four chemical components of dietary fiber Indicate which are carbohydrates 0 Dietary fiber is the edible parts of the plant however they are resistant to digestion The components include cellulose hemicelluloses betaglucans pectins and gums Describe in words the chemical structure of a triglyceride o A triglyceride has a glycerol molecule that is linked to three fatty acids through an ester anage Distinguish among saturated unsaturated and polyunsaturated fatty acids 0 Saturated fatty acids No double bonds between carbons and completely saturated with hydrogen atoms 0 Unsaturated fatty acids Single double bond somewhere in the chain causing a cis structure 0 Polyunsaturated fatty acids Multiply double bonds within the chain Least amount of Hydrogen atoms For each of the following fatty acids indicate if it is saturated monounsaturated or polysaturated Saturated Monounsaturated Polyunsaturated Palmitic acid Oleic acid Linoleic acid Butyric acid Stearic acid Distinguish between cis and transfatty acids 19 20 21 22 23 24 25 26 27 28 29 30 o Cis configuration has hydrogen atoms on the same side of the double bond while trans configuration has the hydrogen atoms on opposite sides of the double bond What is a simple triglyceride A mixed triglyceride o A simple triglyceride is one formed with three of the same kind of fatty acids 0 A mixed triglyceride is one formed with different fatty acids How do phospholipids differ from triglycerides in chemical structure What useful role do phospholipids play in food preparation 0 Phospholipids differ because instead of a third fatty acid chain attached is a phosphoric group to the glycerol A nitrogen base is also linked with phosphoric acid In food preparation they act as emulsifying agents List several food sources of cholesterol 0 Meat fish poultry egg yolks and milk fat What chemical groups characterize amino acids 0 Amino acids are made of an amino group and a carboxyl or acid group How are amino acids joined to make proteins 0 Amino acids are joined by peptide linkage and hydrogen bonds What is meant by the side chains or R groups of a protein Explain why proteins may act as buffers in foods 0 The side chains or R groups of a protein give its particular characteristics Proteins may act as buffers in foods because they can combine with either acid or base to resist any change in acidity What is an essential amino acid and how many amino acids are so designated for adult humans 0 An essential amino acid is one that can t be synthesized in our body and can only be obtained through food intake From the following list of amino acids identify those that are nutritionally essential o The essential amino acids are isoleucine leucine lysine methionine phenylanine threonine tryptophan valine and histidine Explain the meaning of biological value in relation to proteins Why do some protein foods such as eggs and milk have high biological value while others such as kidney beans and wheat flour have lower biological value 0 Foods like eggs and milk have a high biological value because they contain more of the essential amino acids than foods like kidney beans and wheat flour Explain how proteins can supplement each other to improve the net nutritional value 0 When certain foods are consumed together the amino acids within the foods can complement each other in order to create a complete protein Name several food sources that are relatively high in protein 0 Milk Cheese Egg yolk and white lean meat wheat brazil nut Describe in general the primary secondary tertiary and quaternary structure of proteins 0 Primary Structure The peptide linkages that produce long chains of proteins 0 Secondary Structure The springlike coiling of the long peptide chains 0 Tertiary Structure Occurs when the secondary coils fold back onto themselves forming a compact structure and irregular shape 31 32 33 34 35 36 37 o Quaternary Structure Results when some globular proteins combine with other proteins Describe what probably happens when a protein is denatured List at least four treatments likely to be applied to foods that can cause protein denaturation o Denaturation occurs when a protein molecule unfolds to some degree yet still retains all peptide linkages between the amino acids 0 Causes to protein denaturation include coagulation change in degree of acidity changing the concentration of mineral salts or freezing Explain what probably happens when proteins are coagulated and describe some examples of coagulation in foods 0 When proteins are coagulated they bind together and produce a gel or solid mass An example of this is shown when cooking eggs or roasting meat What is a catalyst What are the enzymes and how do they act as catalysts o A catalyst is used to speed up the rate of reaction Enzymes act as catalysts by combining with a substrate to aid in the reaction process Suggest a mechanism of action for enzymes 0 Enzyme Substrate Enzyme Product Give examples of hydrolytic enzymes 0 Hydrolytic enzymes are those that catalyze hydrolysis reactions Explain why enzymes are important in food processing and preparation 0 Enzymes are important in food processing and preparation because it can cause protein denaturation that allows certain food to tenderize or cause the clotting of milk to manufacture cheese Describe what is meant by the terms dispersion system dispersed phase dispersion medium solution solute and solvent 0 Dispersion system substances combined with other substances 0 Dispersion phase A scattered substance or subdivided throughout another continuous substance 0 Dispersion medium The dispersion phase is scattered throughout this Chapter 11 1 List the common sugars in order of their solubility s in water at room temperature Describe how the solubility of sugars is affected by temperature 0 Most soluble to least includes Fructose sucrose glucose maltose and lactose Describe a saturated and supersaturated solution in making crystalline candies o A saturated solution occurs when sugar is added to water and the mixture is stirred dissolving all of the sugar which allows for more sugar to dissolve if added 0 A supersaturated solution occurs when it holds more solute than is usually soluble at a particular temperature What happens when sugar is heated in a dry state above its melting point Why is this reaction important in food preparation 10 11 0 When sugar is heated in a dry state it will start to caramelize This is important in food preparation because it can be used as a flavoring for puddings ice creams frosting and sauces What is meant by hygroscopic Which is this most hygroscopic sugar 0 Hygroscopic means the ability for sugars to absorb moisture from the atmosphere Name the two monosaccharides that result from the hydrolysis of sucrose What catalysts may cause sucrose hydrolysis o Glucose and fructose result from the hydrolysis of sucrose Heat and acid solutions act as a catalyst for sucrose hydrolysis Describe examples of the importance of this reaction in food preparation particularly in candy making o In food preparation the hydrolysis reaction can produce a soft and semi fluid center in chocolate along with causing a strong or bitter flavor Compare the common sugars for relative sweetness Discuss several factors that affect these comparisons Under what conditions is fructose likely to taste most sweet 0 The degree of sweetness is affected by genetic variation among individuals temperature and concentration of the sweetener viscosity pH and the presence of other substances 0 Lactose in the least sweet followed by maltose galactose glucose sucrose and fructose being the most sweet 0 Fructose is the sweetest in a slightly acidic environment like cold foods and beverages Describe the major characteristics of each of the following Granulated sugar Sucrose Powdered sugar Sucrose and cornstarch Brown sugar Sucrose coated in molasses Corn Sugar 75 carbohydrate containing 2098 glucose and 25 water HighFructose corn syrup Same as corn syrup however 12 of the glucose is changed to fructose Molasses The residue that remains after sucrose crystals have been removed from the concentrated juices of sugarcane Honey Is a supersaturated solution and the glucose tends to crystallize Maple Syrup Created from the evaporation of sap to a concentration containing no more than 35 water then cooking down the sap into syrup Discuss trends in sweetener consumption in the United States in recent years 0 Americans have considered the use of low calorie sweeteners and other sugar substitutes List some sugar alcohols and describe their possible uses in foods 0 Sugar alcohols are used in foods to improve bulk mouthfeel and texture when combined with lowcalorie sweeteners Some include erythritol mannitol isomalt lactitol maltitol and xylitol What is the present legal status of saccharin in the United States 0 Saccharin is the only legal nonnutritive in the United States and currently has been removed off the list of the federal ban of the none human carcinogens 12 13 14 15 16 17 18 19 20 Discuss some advantages and limitations to the use of alternative sweeteners in manufactured foods 0 Advantages Doesn t promote tooth decay less or no calories than sugar diabetic friendly 0 Limitations Makes your sugar tolerance higher bad aftertaste Give examples of bulking agents and describe their role in the production of reduced sugar foods 0 Bulking agents are used with artificial sweeteners in order to provide volume texture and a thickened consistency It also contains less calories than real sugar What is the effect of sugar on the boiling point of water Explain 0 Sugar added to water decreases the vapor pressure and increases the boiling point Describe what happens as you continue to boil a sugar solution 0 The sugar becomes more concentrated and start to crystallize Name two major classifications for candies Describe the general characteristics of each type 0 Crystalline candies Generally soft creamy and have small sugar crystals that can t be felt on the tongue Ex Fondant fudge and panocha o Noncrystalline candies Without form and chewy Ex Caramels butterscotch toffees and brittles Describe the basic effects involved in the preparation of crystalline candies such as fondant and fudge Explain what is happening in each step and how crystallization is controlled 0 It is controlled by boiling the solution until all of the sugar has dissolved Describe the basic steps involved in the preparation of brittles and caramels Explain how crystallization is prevented in each case 0 It is prevented by heating the sugars to very high temperatures so that the product hardens Suggest several uses for basic fondant o Fondant is used in bonbons fondant loaves and chocolates with a fondant center As well as on decorative cakes and fondant patties Describe and explain several precautions that must be observed for successful dipping of chocolates 0 Successful dipping of chocolate relies on the use of suitable chocolate controlled temperatures avoidance of humid atmosphere and thorough stirring or hand manipulation Chapter 12 Describe the major characteristics of a wellprepared frozen dessert such as ice cream or sherbet 0 They have a smooth creamy somewhat dry and stiff texture with tiny ice crystals enough that the product melt slowly and uniformly Also has a sweet fresh characteristic flavor Describe identifying characteristics of each of the following Sherbet Contains fruitjuices sweeteners stabilizers and 25 milk solids Water ice Contains water sugar and flavoring Large ice crystals present Ice cream At least 10 milkfat and must weigh at least 45 lbs per gallon Sorbet Contains frozen fruit or fruit juice sugar and stabilizers Air whip may be up to 20 Frozen Yogurt Lower in fat than ice cream and must contain bacteria cultures Mellorine Milkfat is replaced with whole or part vegetable or animal fat Not less than 6 fat and 27 protein Paravine Contains no dairy ingredients Reducedfat ice cream Made with 25 less fat than standard ice cream What is the effect of each of the following on the flavor texture andor body of a frozen ice cream Milk fat Produces a fine smooth texture Nonfat milk solids Improves the texture and flavor Sweeteners Changes flavor and affects freezing points Stabilizers Adds body to the ice cream Overrun Causing a light smooth texture or heavy compact coarse texture How does sugar affect the freezing point of ice cream mix o If too much sugar is added it will lower the freezing point if not enough sugar is used the water will become frozen and affect the texture of the ice cream Discuss some of the problems often involved in the formulation of acceptable light frozen desserts What are some possible solutions to these problems o It is difficult to produce high quality light frozen desserts without reducing the amount of sugar and fat used To compensate for the reduction of fat vegetable gums can be substituted Bulking agents are then used to replace the reduction of sugar Explain how a mixture of ice and salt it able to act as a freezing mixture to freeze frozen desserts 0 Salt and ice act as a freezing mixture because it creates a brine that draws heat away from the mixture allowing it to freeze faster What procedures should be used when freezing a frozen dessert without stirring Why 0 StillFrozen desserts should not be stirred to not incorporate air however air should be beaten into cream or evaporated milk prior to freezing Chapter 13 1 Starch is the storage form of carbohydrates deposited as granules in plant cells Describe the appearance of starch granules when viewed under a microscope How do their size and shape differ from one plant source to another o It is a polysaccharide made up of hundreds of glucose molecules joined together Name the two fractions of starch Explain how they differ in structure 0 Amylopectin High branched bushy structure Many short chains of glucose branched together 0 Amylose A long linear chainlike molecule produced by linking 5002000 glucose molecules Explain why some natural starches are chemically modified Give examples of the types of chemical modifications most commonly used 10 11 12 13 0 Chemical modification is used to achieve a texture or flavor in the finished product that must undergo high temps low pH or freezethaw cycles during production 0 Hydrolysis Mixing starch with water and an acid to produce a random breaking of linkage points along the molecular chain 0 Crosslinking Modified to lower viscosity and increase temperature for hydration o Substitution Used to prevent retrogradation of cooked starch How can native starches be improved for desirable uses in food processing lessening the need for chemically modified starches 0 They can be physically modified by drumdrying extrusion spray drying heat or moisture treatment What products are produced as starch is hydrolyzed What may catalyze this process o It produces a paste with low viscosity when boiled and hydrates at a lower temperature than unmodified starch but then produces a stiff gel Acid is used to catalyze the process What are resistant starches o Resistant starches are those not digestible by the human body There are 4 main types R51 R52 R53 and RS4 which is the only chemically modified starch They are used to increase total dietary fiber in foods without changing quality What is wet milling 0 Wet milling is the separation of grains and tubers from purified starch Compare and contrast the use of each of these sources of starch Cornstarch Used as a thickener in sauces puddings and gravy Clearer glossy sauce Tapioca Used to thicken puddings or pie fillings More tolerant to freezing and thawing Wheat Thickener however products don t have a glossy finish Potato Gluten free used to thicken soups and gravies Rice Used in Asian desserts tolerates freezing Arrowroot Gives a shiny gloss to foods able to heat more than other starches and freeze Sago Used to thicken pudding or a variety of other dishes Describe what happens when dry starches are heated What is this process called 0 The starch becomes more soluble and a toasted flavor develops This is known as dextrinzation Why is gravy made from browned flour usually thinner than gravy made from the same amount of unbrowned flour Explain o By browning the flour it develops a lesser ability to thicken Describe what happens when starch granules are heated in water What is this process called 0 When starch granules are heated in water in irreversible process occurs known as gelatinization where water is being absorbed by the starch granules When starch is heated even longer a paste will occur What is birefringence What does its presence or absence tell you about the starch o Birefringence is the phenomenon observed when polarized light is used to view the microscopic starch granules and a maltese cross pattern is observed When starches are cooked they lose this Describe the general effect of each of the following on the thickness of a cooked starch mixture 14 15 16 17 18 19 20 Rate of heating It is important to control the rate of heating so the starch has a silkt mouthfeel and does not produce thinner mixtures than expected or over swelling Excessive stirring If over stirred the starch granules will rupture and decrease viscosity giving a slick pasty mouthfeel Addition of sugar Causes the starch to gelatinize at a higher temperature and the granules do not swell as much causing a decreased thickness of the paste Many starchthickened mixtures become stiff or rigid on cooling What is this process called What happens in the starch mixture to bring about it o The process is known as retrogradation and when cooled it forms a gel that can reassociate some of the starch molecules What is synersis Why may it occur in cooked starch mixtures o Synersis or weeping results from increased molecular association as the starch mixture ages Which of the common starches forms the stiffest and which the softest pudding when used in equal amounts Explain o Starches containing more amylose like cornstarch form firmer gels than those that contain more amylopectin like tapioca Distinguish between gelatinization and gelation of starch mixtures o Gelatinization occurs when starch granules gradually swell when heated in hot water and the structure of the granule is changed 0 Gelation occurs when starch is cooled and the granules have already been gelatinized Describe three ways to keep powdery starches from lumping together when they are added to a hot liquid Explain what is happening in each case 0 Dispersing the dry starch with melted fat to make a roux This process mixes flour and butter to form a paste consistent with that of wet sand 0 Mixing the starch with cold water to form a slurry This process mixes flour with cold water until the consistency is like a thick cream 0 Blending the starch with sugar Describe appropriate methods for preparing each of the following items Explain why these methods should be successful White sauce Starch thickened from fat flour liquid and seasonings Cream of vegetable soup One tbsp of flour to 1 cup liquid Thinner than white sauce Cream of tomato soup Acid is added to the white sauce gradually at serving time to prevent curdling Cornstarch pudding Thickened with starch to produce smoother mouthfeel Cornstarch pudding with egg Thickened with starch then egg is added What types of instant starch are available to the food processor How do these differ from each other Give examples of products in which the consumer may expect to find instant starches used 0 Instant starches can be found in dry mix puddings gravies and sauces Chapter 14 1 Name the most important cereal grains used for food 0 Wheat corn rice oats rye barley and millet are the most important 2 The structures of all grains are somewhat similar Name three major parts of a grain Describe the general chemical composition of each part 0 The three parts include the bran the germ and the endosperm o The bran is the outer coating of the grain and has a high content of fiber 0 The germ is a small structure at the lower end of the kernel where the new plant grows It is rich in fat protein ash and vitamins o The endosperm is the large central portion of the kernel and constitutes about 83 of the grain Containing the most starch and protein What is the aleurone of a cereal grain Describe its general composition and indicate where it usually goes during the milling of grain o The aleurone layer comprises the square cells located just under the brand layers When milled the layer is usually removed It is 8 of the kernel 3 What is meant by enrichment of cereals and flours o Enrichment of cereals and flours is a white flour where specified B vitamins such as thiamin riboflavin niacin have been added Along with the addition of folic acid and iron 4 Compare the general nutritional value of refined unenriched enriched and wholegrain cereal products 0 Whole grain Contains more of the necessary added nutrients except riboflavin and does not contain folic acid 0 Enriched Contains more riboflavin and folic acid than whole grains however less in other required added nutrients o Unenriched Contains less to no nutrients needed 5 Indicate which grains are commonly used to make the following products Briefly describe the processes involved in preparing the grain Uncooked breakfast cereals Corn wheat corn barley Prepared breakfast cereals Oats Flour Rye wheat buckwheat Meal Hominy Grits Corn Pasta Triticale 6 What are the main purposes for cooking cereals 0 To improve palatability and digestibility 7 Suggest appropriate methods for cooking each of the following cereal products Explain why these methods are appropriate Granular cereals such as farina and corn meal You should avoid lumps by adding cereal to cold water and briefly stirring or pour into boiling water and stir enough onto to separate the grains Rice Cooked until it is tender and has fully absorbed all the water Macaroni or spaghetti Should be cooked until al dente Chapter 20 1 What are vegetables Give definitions 0 Vegetables are plants or parts of plants that are used as food 2 List eight classification groups of vegetables based on parts of the plant that are used as food Give examples of vegetable in each category 0 Leaf Vegetables Lettuce cabbage Brussel sprouts cactus greens spinach and water cress o VegetableFruits Tomatoes pumpkin eggplant okra peppers cucumber summer squash 0 Flowers Artichoke broccoli and cauliflower o Stems and shoots Asparagus celery fennel and kohlrabi 0 Roots Carrots celery root ginger jicama and parsnip o Tubers Potatoes radish Rutabaga sweet potato and turnips o Bulbs Garlic Leek onion and shallot 0 Seeds Corn and peas 3 Describe characteristics of mealy potatoes and waxy potatoes 0 Mealy potatoes separate easily into fluffy particles that feel dry 0 Waxy potatoes are more compact and moist or almost soggy and does not separate into fluffy particles 4 For what uses is each type of potato best suited Why 0 Mealy potatoes are best used for baking mashing drying and roasting o Waxy potatoes are best used for boiling or in salads or dishes such as scalloped potatoes 5 Explain why the green pigmentation that sometimes develops on potatoes exposed to light should not be eaten o It is the formation of solanine a bitter alkaline substance that is toxic if consumed in relatively large amounts 6 Indicate which types of vegetables can be characterized generally as follows High in water content Vegetable fruits flowers stems leafs High in starch Bulb roots and tubers seeds High in protein None High in fiber Good sources of vitamin A and C Leaf veggies vegetable fruits flowers tubers Low in kilocalories All categories besides bulb root and tubers 7 List at least three plant polysaccharides that are components of dietary fiber 0 Cellulose resistant starch pectin betaglucans and oligosaccharides 8 The color of fruits and vegetables is due to their certain pigments List five groups of plant pigments Describe the color for each group 0 Chlorophyll Green pigments o Carotenoids Yellow and orange sometimes pink or red 0 Anthocyanin s Red purple and blue 0 Betalains Purplish red some are yellow 0 Anthoxanthins Creamy white to colorless 10 11 12 13 14 15 16 17 18 19 20 21 Flavor varies from one vegetable to another and many substances contribute to the characteristic flavors List two different families of vegetables that are considered to be strong flavored and indicate what types of compounds are responsible for these flavors 0 Strong flavors Cabbage and cabbage family caused by the decomposition of sulfur Describe the usual characteristics of fresh vegetables of good quality 0 Should be firm crisp and bright in color Suggest important factors to consider in purchasing fresh vegetables You should consider size shape gloss color absence of defects and freshness What advantages result from the use of grades on fresh fruits and vegetables 0 It provides a common language for wholesale trading and aids in establishing prices based on quality What factor most limits the use of grades on fresh fruits and vegetables 0 Quality may change between the time of grading and the time of purchase List three USDA grades that may be used on canned and frozen vegetables Discuss the value to the consumer of grading these products 0 Grades include US Grade A or fancy US Grade B or Choice or US Grade C or Standard They are graded based on color uniformity of size shape tenderness or degree of ripeness Suggest appropriate methods for storing various types of fresh vegetables to retain quality 0 Leafy greens store best in highhumidity locations however excess moisture can cause spoilage Several kinds of roots tubers and winter squash are typically not refrigerated Potatoes are generally not stored in a fridge and tomatoes are best at room temperature Several vegetables such as leafy lettuce cucumbers asparagus celery beets carrots peas and broccoli should be stored in the refrigerator Describe some advances in biotechnology that can be used to improve some characteristics of vegetables and fruits Give examples 0 Gives increased tolerance to herbicides used to kill weeds and to avoid pests thus reducing the need for pesticides Why is it important to cleanse fresh fruits vegetables thoroughly as a first step in their preparations 0 Washing is important to remove soil sand and pesticide residue that can lead to illness Describe eight appropriate methods for cooking vegetables 0 Cooking methods include broiling grilling roasting baking panfrying deepfat frying saut ing boiling steaming pressure cooking and microwave Explain why frozen vegetables require less time for cooking than similar fresh vegetables 0 Frozen vegetables require less time to cook than fresh vegetables because they are already blanched before freezing Outline a satisfactory method for cooking dried beans and explain why this procedure would be appropriate 0 Beans should be soaked before cooking to rehydrate and make proteins more available List and describe several different legumes o Dried beans peas and lentils 22 Describe various types of vegetarian diets o Semivegetarian Eats dairy products eggs chicken and fish but no other animal flesh o Pescovegetarian Eats dairy products eggs and fish but no animal flesh o Lactoovovegetarian Eats dairy products and eggs but no animal flesh o Lactovegetarian Eats dairy products but no animal flesh or eggs 0 Ovovegetarian Eats eggs but no other dairy and no animal flesh 0 Vegan Eats no animal products of any type 23 What flavor problem has limited the use of soybeans in the United States in past years How has it been solved 0 They have been said to be quotpaintyquot or quotbeanyquot 24 Describe several soy products that are available for use in manufactured foods 0 Soy beans soy milk tofu and soy sauce 25 What is tofu How might it be used in food preparation 0 Tofu is soy cheese or bean curd It can be used to extend fish and chicken dishes crumbled in salads create an attractive cheese cake Chapter 21 1 What is a fruit 0 A fruit is produced from a flower and can be fleshy pulpy and often juicy 2 Define a pome and a drupe Give examples of each 0 Pomes are apples and pears o Drupes are fruits with a stone or pit which incloses the seed 3 What is the usual percentage of water found in fruits What is the usual percentage of carbohydrates found in fruits What type of carbohydrate usually predominates in ripe fruits 0 Usually contains around 85 water 0 Carbohydrates are mainly sugar 0 Coconut and avocado have a large amount of fat 0 Trace amounts of protein in fruit 4 List and be able to recognize fruits that are good sources of vitamin C 0 Citrus fruits are high in vitamin C strawberries and cantaloupe are also significant sources when in season also guava and kewi 5 Describe common characteristics of fruit flavor and list four types of chemical substances that contribute to that flavor of fruits 0 Fruit flavors include tart fragrant and sweet Chemical compounds such as esters aldehydes alcohols and organic acids 6 What pigments are often present in fruits o Chlorophyll Green 0 Carotenoids Yellow and orange 0 Anthocyanins Red purple orange 0 Betalains Purplered 10 11 12 13 14 15 o Anthoxanthias Creamy white and colorless Explain why pigment content should be considered when mixing various fruit juices to make a fruit drink 0 Mixing the wrong colored fruit juices can produce unattractive results because the metals can combine changing the original pigments Describe the major changes that occur during ripening of fruit 0 Ethylene gas naturally promotes ripening Decrease in firmness and loss of pigment chlorophyll may occur Describe the usual characteristics of fruits of good quality and suggest appropriate storage conditions to maintain quality 0 Proper stage of ripeness good color freedom of insect damage What factors are generally monitored during controlledatmosphere storage of fruits and vegetables Why is this type of storage effective for some fruits 0 Most fresh fruits should be kept refrigerated Berries should be kept spread out avocados and bananas should be left at room temp Explain what is involved in modifiedatmosphere packaging o This modifies the oxygen carbon dioxide and water vapor levels in the air surrounding a product What contributes to the stability of the hazy cloud characteristic of orange To what treatment may the juice be subjected during processing to maintain cloud formation Explain why this treatment is effective 0 Haze is a complex mixture of cellular organelles color bodies oil droplets flavonoids and cell wall fragments that include pectic substances cellulose and hemicellulose What special processing that involves enzyme action may be used to produce a sparkling clear fruit juice Describe and explain 0 The process clarification uses the enzyme pectinases to produce a clear fruitjuice Why are some fruits treated with sulfur before drying Describe some effects of this process on nutritive value 0 Sulfur aids in the preservation of vitamins A and C but effects thiamin Describe several additional methods for cooking fruits o Glazing o Saut ing o Broiling Grilling HNF 300 F14 Exam 3 Chapters 10 22 23 24 Review Chapter 10 Summary Fats are present in many foods and play a variety of roles in food preparation and nutrition Fat present naturally is often referred to as invisible fat whereas fats that are added to foods are called visible fats To reduce the risk of heart disease saturated fat intake of 10 or less of kilocalories is recommended Solid fats including tropical oils are high in saturated fats therefore should be limited in consumption Fats provide essential fatty acids and carry the fat soluble vitamins and therefore in moderation are important to the diet Fats contribute flavor color texture tenderness and moistness to foods Fats are an effective method of heat transfer and are one phase of emulsions Fats are insoluble in water Fats that are solid at room temperature are called fats and those liquid at room temperature are called oils The melting point of fat is influenced by the type of fatty acids form of the fatty acids cis or Trans and length of the carbon atoms Fats demonstrate plasticity because of a unique combination of liquid and solid crystals that allows the fat to be molded or pressed into various shapes Hydrogenation changes liquid oils into solid fats such as shortening or margarine by adding hydrogen Other methods of processing oils to produce the desirable characteristics of hydrogenation fats being used to reduce transfatty acids produced during hydrogenation Interesterification and fractionalization are two such methods Oils are obtained from fruits seeds and nuts generally by pressing Winterized oils or salad oils have been processed to remove the triglyceride molecules that crystalize or become cloudy under refrigeration Butter is the fat of cream that is separated from the other milk constituents by agitation or churning Butter is a waterinoil emulsion Lard is the fat rendered from the fatty tissues of the hog Although lard is used less widely than in the past it is still preferred by some for pie crusts and biscuits due to its shortening ability and for the flavor it provides in Mexican cuisine Fat may deteriorate in flavor due to rancidity resulting from hydrolysis or oxidation A special type of oxidative deterioration flavor reversion involves a change in edible fats characterized by the development of an undesirable flavor Fats can be protected against rancidity to some degree by controlling the storage conditions and by using antioxidants Panfrying and deep frying are two methods of cooking that utilize fat as the cooking medium Fats selected for deepfat frying must highly stable have a high smoke point and have a neutral or desirable flavor Fats that become excessively dark foam or smoke at a normal temperature for deepfat frying should be discarded Fats that are well maintained by routine straining and filtering will last longer Several factors influence the amount of fat absorbed by foods when cooked by deep fat frying The amount of fat can be reduced when cooking through the careful selection of low fat foods cooking methods and recipes Food processors are using a variety of ingredients to replace or partially replace fat in food products Fat replaces must be GRAS or must be approved by the FDA as food additives Fat replacements may be fat based carbohydrate based or protein based Emulsions are found naturally in many foods or may be formed during processing or preparation The term emulsion is applied to a system consisting of one liquid dispersed in another liquid with which it is immiscible Temporary emulsions separate on standing Permanent emulsions such as mayonnaise can be held or stored without separation There are many types of salad dressings that can be purchased commercially or made in the home Mayonnaise French dressing and salad dressing all must meet standards of identity to be labeled with these names in the marketplace Chapter 22 Salads include a wide array of dishes including mixtures of meat fish poultry cheese nuts seeds and eggs as well as all kinds of vegetables and fruits Salads may be served before the main course or as a dessert Salads can contribute to the goal of consuming more fruits and vegetables A variety of ingredients may be used to prepare salads Leafy greens vegetables fruits pasta grains legumes meat poultry fish and eggs are all used to create salads Sanitary food handling practices are important in salad preparation to reduce the risk of foodborne illness Most salads should be prepared shortly before the salad is to be served When preparing salad plants wash thoroughly and remove inedible portions Storage of the vegetables in the refrigerator after washing will provide an opportunity for the vegetables to crisp Salad ingredients may be marinated to improve flavor The length of time that salad ingredients are marinated varies with the type of ingredient Excess marinade is drained off during final preparation of the salad Many types of salad dressings are available Dressing may be placed on some salads in advance and others are added just before service or are provided on the table for individuals to serve themselves Salads should be attractively arranged with a consideration for color and shape Garnishes provide decoration but are also edible constituents that form part of the salad Salads should be properly refrigerated and maintained cold to prevent to prevent foodborne illness Special attention is needed to control the temperature of salads at summer picnics Any salad composed of high protein neutral pH and high moisture foods will spoil readily if temperature abused Gelatin is a highly efficient gelling agent It may be used in various salads and desserts as a foam stabilizer or thickener or to control crystal size in some candies Gelatin is obtained by the hydrolysis of collagen The chief sources of commercial gelatin are animal hides skins and bones Gelatin is a protein food derived from animal sources yet it is a protein of low biological value A gel is a special kind of structure that might be described as something between a solid and a liquid Gels occur in a variety of food products including most starchthickened puddings and pie fillings eggs custards fruitjellies and gelatin molds Gels are composed on mainly fluid but they behave much like rigid solids Gels contain long thin chain like molecules called polymers that are joined or crosslinked at random spots to produce a three dimensional structure something like a pile of brush Gels may vary from being soft to fairly rigid Temperature concentration degree of acidity and presence of salts sugar and enzymes influence the strength of the gelatin gel When preparing gelatins with canned fruits the juice should be drained and then used as part of the measured liquid Generally solid ingredients should be added to a gelatin mixture after the gelatin has partially set or the ingredients will float rather than being evenly dispersed Aspics are usually a beef flavored gelatin mixture although fish poultry and tomato aspics may also be prepared A gelatin dispersion can be beaten to form a foam It will increase two to three times its original volume Bavarian creams include fruit pulp and whipped cream Spanish creams are prepared with a soft egg custard whipped egg whites and gelatin Chapter 23 The annual per capita consumption of milk has decreased Yogurt and cheese consumption has increased Milk is rich in calcium and provides a dependable source of riboflavin vitamin A vitamin D when fortified and protein Milk is composed of water carbohydrate protein fat and ash minerals Casein and whey are the two primary types of protein in milk The milk fat is composed of primarily triglycerides but also phospholipids and sterols The fat in milk is dispersed in milk serum thus milk is an emulsion The chief carbohydrate is lactose Some individuals may be lactose intolerant and may find dairy products such as yogurt aged cheese and lactose reduced milks to be better tolerated The white appearance of milk is due to the reflection of light by colloidally dispersed casein micelles and calcium phosphate salts Carotenes and riboflavin are two yellowish pigments that are also contribute color to milk The flavor of milk is bland and slightly sweet with a mild aroma Off flavors may be produced when milk is exposed to light Fresh milk has a nearly neutral pH Raw milk gradually increases in acidity on storage because of lactic acid producing bacteria The grade A pasteurized milk ordinance provides regulations to protect the milk supply Sanitary codes generally determine the grading of milk If a manufacturer of dairy products uses the USDA grade or quality approved shield on product labels the plant must operate under continuous inspection of USDA agents Pasteurization is required by law for all Grade A fluid milk and milk products that enter interstate commerce for retail sale The pasteurization process involves heating raw milk to a sufficiently high temperature for a specified length of time to destroy pathogenic bacteria Homogenization consists of pumping milk or cream under pressure through tiny openings to increase the dispersion of fat and prevent the cream from separating on standing Milk is commonly fortified with vitamins A and D The fortification with vitamin D is optional but vitamin A fortification is required in low fat and nonfat milks 0 Milk is marketed as fluid milk reduced fat fluid milk concentrated fluid milk dry milk cultured milk products filled or imitation milks and cream 0 Heat acid enzymes phenolic compounds salt and freezing have an effect in milk and milk products 0 Several changes may occur when heating milk Whey proteins coagulate calcium is less dispersed and may precipitate fat gobules coalesce surface films may form and the sugars and proteins may brown 0 Casein is highly sensitive to precipitate on the addition of acid This curdling is desirable when making products such as buttermilk yogurt sour cream and some cheeses o A number of enzymes from plant animal and microbial sources are capable of clotting or curdling milk Chymosin or rennin is such an enzyme The enzyme bromelin found in fresh pineapple also clots milk but later digests the clot o Phenolic compounds found in plants may cause curdling of milk when cooked Sodium chloride also promotes coagulation of casein 0 Fat globules tend to coalesce when milk or cream has been frozen The dispersion of protein and calcium phosphate is also disturbed by freezing 0 Milk products such as cream evaporated milk and nonfat dry milk may be whipped to create a foam Cream that is cold and higher in fat than 30 will whip most successfully Sugar should be added after the cream is stiff o Fluid milk should be stored at 41 degrees or below immediately after purchase The milk container should be closed to prevent absorption of other food odors Milk should be protected from light to retain riboflavin Nonfat dry milk should be stored in moisture proof packages at room temperature or cooler Evaporated milk should be turned periodically to retard the settling of milk solids 0 Cheese is a concentrated dairy food defined as the fresh or matured product obtained by draining the whey after coagulation of casein Cheese manufacture usually involves 1 curd formation with a starter culture andor a coagulating enzyme 2 curd cutting to drain the whey 3 curd heating 4 draining knitting or stretching salting and pressing 5 curing or ripening The changes in cheese during ripening affect flavor and texture and improve cooking quality 0 Various types of organisms produce distinctive flavors aromas and textures in cheeses The mottled green appearance of some cheeses is due to the type of mold used Swiss cheese owes it large holes to special gas forming organisms 0 Cheese may be classified by the amount of moisture and the kind and extent of ripening USDA grade standards have been developed for some varieties of cheese 0 Cold pack or club cheese process cheese and process cheese foods are made by grinding and mixing together additional samples of natural cheese Additional ingredients and processes are allowed depending on the type of process cheese 0 All cheese should be stored cold although the flavor of many cheese is best when served at room temperature Freezing is generally not recommended 0 When cooking with cheese finely dividing the cheese by grating will facilitate melting without overheating The overheating of cheese results in the separation of the fat and the development of a tough rubbery curd Chapter 24 Eggs function in several roles in food preparation because of the ability to emulsify foam form gels coagulate and clarify liquids Essentially all of the fat and cholesterol can be found in the yolk The white is higher in water The major protein in the egg white is ovalbumin Lipoproteins are the major proteins in the yolk The lipoproteins are responsible for the emulsifying properties of egg yolks The lipids in egg yolk include triglycerides phospholipids and cholesterol The predominant yellow pigment of the yolk is xanthophyll No difference in nutritional value in noted between infertile and fertile eggs The eggshell is porous and allows for the exchange of gases and loss of moisture from the egg Eggshells may be brown or white depending on the breed of the chicken The natural cuticle may be replaced with a light oil coat after washing to reduce loss of moisture The egg white consists of thin and thick portions Chalazae are two strands if thickened white that anchor the yolk in the center of the egg As eggs age the proportion of thin white increases the chalazae disintegrate the yolk absorbs water from the white the air cell increases in size and alkalinity increases USDA grades for eggs are based on their candled appearance Grades AA and A eggs have larger portions of thick white that stands up around a firm high yolk Eggs are sorted into six weight classes Recipes are generally formulated on the basis of the large size Adjustments in recipes can be made for different sizes of eggs The FDA and the USDA share federal responsibilities for egg safety Since the mid1980s S enteritids has been frequently implicated in foodborne illness Unbroken shell eggs may contain the bacterium or the eggs may be infected as contamination on the shell exterior moves through the shell pores into the interior In 2000 the FDA finalized regulations to require safe food handling instructions on cartons and to specify refrigeration temperature during storage and sale Raw eggs should not be consumed Pasteurized eggs should be used in recipes such as Caesar dressing Casseroles and other dishes containing eggs should be cooked to 160 degrees F When serving high risk populations the use of pasteurized egg products is recommended Egg processing plants usually do egg breaking separation and pasteurization in preparation for liquid refrigeration products frozen eggs or dried eggs Pasteurization is required by the federal government for all processed eggs The functional properties of raw egg whites are not altered by freezing and thawing However frozen egg yolks become viscous and gummy on thawing unless they are mixed with sugar salt or syrup before freezing Drying is a satisfactory method for the preservation of eggs A variety of egg substitutes are available in the marketplace to offer a low cholesterol egg substitute Coagulation occurs not instantly but gradually Egg yolk protein requires a slightly higher temperature for coagulation compared to egg whites Diluted egg mixtures require a higher temperature for coagulation The use of low or moderate temperature for coagulation The use of low or moderate temperatures for egg cookery is recommended to avoid toughness and greater shrinkage of egg proteins Overcooked yolks may develop a green color Factors influencing the coagulation of egg proteins include 1 rate of heating 2 sugar in the mixture or 3 acid in the mixture Egg whites coagulate with mechanical beating First egg whites become foamy then soft moist peaks form Stiff peaks form with continued beating but overbeating will result in a dry lumpy foam The foam produced from thin whites is fluffier and has less body than one created from thick viscous whites Thick whites produce a more stable foam Eggs whip more easily and quickly at room temperature Whole eggs and egg yolks may also be beaten but produce less volume than egg white foam include 1 type of beater used 2 type of bowl used 3 or added substances such as fat salt acid and sugar Cream of tartar and sugar stabilize egg white foams but sugar should not be added until later in the whipping process Poached hard cooked or soft cooked in the shell fried scrambled shirred omelets crepes custards meringues and many other egg dishes may be prepared Microwave ovens may be used to prepare scrambled fried poached and other egg dishes However microwave ovens are not recommended for hard or soft cooked eggs in the shell because the shell can burst
Are you sure you want to buy this material for
You're already Subscribed!
Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'