Food, Folklore, & Health
Food, Folklore, & Health FST 010
Popular in Course
Popular in Food Science & Technology
This 5 page Class Notes was uploaded by Orlando Ondricka on Tuesday September 8, 2015. The Class Notes belongs to FST 010 at University of California - Davis taught by Staff in Fall. Since its upload, it has received 30 views. For similar materials see /class/191767/fst-010-university-of-california-davis in Food Science & Technology at University of California - Davis.
Reviews for Food, Folklore, & Health
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: 09/08/15
Lecture 6 Main topics FOOD SAFETY cont Intoxications Bacterial intoxications Examples Botulism is a rare but deadly disease Caused by toxin produced by Clostn39dium botulinum bacteria It is a neurotoxin if untreated can cause paralysis and respiratory failure which can be destroyed by high temperatures SEAFOOD POISONING Paralytic shellfish poisoning caused by of saxitoxins produced by dinoflagellates These can grow to large numbers leading to quotred tidesquot Shell sh that have caused this disease include mussels clams scallops among others In cases of severe poisoning muscle paralysis and respiratory failure occur may result in death Saxitoxins are heat stable Pufferfish Poisoning Fugu Poisoning Toxicity is due to Tetrodotoxin there is no antidote available Treatment is supportive to maintain respiration OTHERS Mushroom Poisoning The mushroom Death cap produces amatoxins the most hazardous of the mushroom toxins A single mushroom can kill an adult Protection of Food Supply FDA All foods except meat and poultry USDA Meat and Poultry products Smell Taste amp Flavor Olfactory receptors in the nasal passages can detect volatiles Basic Tastes Sweetness Saltiness Bitterness Sourness Umami Astringency Pungency see McGee p 270272 Food as energy source Energyyielding nutrients Carbohydrates 4 Caloriesg Lipids 9 Calories g Proteins 4 Caloriesg Lecture 7 Main topics CARBOHYDRATES Simple Sugars Monosaccharides eX Glucose Fructose Galactose Disaccharides eX Sucrose Lactose Maltose Glucose also called dextrose Fructose also called levulose SUCROSE glucose fructose LACTOSE glucose galactose MALTOSE glucose glucose Glycosidic bond Linkage between 2 monosaccharide units Sweetness Simple sugars differ in sweetness taste intensity Sucrose is used as the reference sugar RELATIVE SWEETNESS is a measure of how sweet a specific substance is in relation to sucrose Sucrose 100 Lactose 20 Glucose 70 Fructose 120 Common Sweeteners Natural Sweeteners Sugar table sugar Hone Maple Syrup Corn Syrup High Fructose Corn Syrup Sugar table sugar refined sugar gt 999 Sucrose Disaccharide GlucoseFructose Only taste is sweetness Commercial sources sugarcane sugar beets Molasses from sugar cane Contain substances other than simple sugars Various grades amp darkness of color such as blackstrap molasses Brown sugar Most is produced by the addition of molasses to refined white sugar Has a more complex flavor than white su a It is hygroscopic holds moisture and makes things stay moist Sucrose Hydrolysis by invertase Sucrose gtGlucose Fructose Honey main sugars glucose and fructose Maple syrup 23 sugars and 13 water main sugar is sucrose Alternative Sweeteners Sugar alcohols are reducedcalorie sweeteners Nutritive Sweeteners High Intensity Sweeteners also called Nonnutritive Artificial or Synthetic Sweeteners Sugar alcohols eX sorbitol mannitol xylitol etc Commercially prepared by hydrogenation of simple sugars Xylitol is as sweet as sucrose it is noncariogenic High Intensity Sweeteners Taste sweet but without the added calories Approved by the FDA saccharin aspartame acesulfame K sucralose and neotame Lecture 8 Main topics Aspartame warning on label Phenylketonurics contain phenylalanine Carbohydrates cont Oligosaccharides contain 3 1O sugar units Example Fructooligosaccharides FOS Glucose Fructosen Fructose FOS are not digested by intestinal enzymes used as ingredients of some functional foods PREBIOTICS stimulate the growth of some microbes in the gut resulting in health benefits Functional Food food that may provide a health benefit beyond basic nutrition Prebiotic is a type of functional food Polysaccharides gt 10 units see McGee p 804 STARCH composed only of glucose units two types of chains Amylose linear and Amylopectin branched Deposited in starch granules insoluble in water see McGee p457 Starch Gelatinization and Starch Retrogradation see McGee p458 Stale bread and starch retrogradation Reheating reverses staling see McGee p542 Corn starch and production of Sweeteners corn syrup and high fructose corn syrup Starch hydrolysis by acid or enzymes such as amylases see McGee p677 Partial hydrolysis produces maltose and maltodextrins Complete hydrolysis produces only glucose Ordinary corn syrup can be treated with enzymes isomerase to produce high fructose corn syrup HFCS HFCS sweeter than glucose and cheaper than sucrose DIETARY FIBER Plant food components that cannot be broken down by our digestive enzymes Constituted mainly of plant cell wall material Mostly of polysaccharides Cellulose hemicelluloses pectins gums and mucilages CELLULOSE long straight polymers of glucose linked by glycosidic betabonds which are not broken down by intestinal enzymes That is why cellulose is part of the dietary fiber PECTINS Form a cement in the plant cell wall and between walls In foods pectins are used as gelling agent thickener In the making ofjams and jellies pectins are released during boiling of fruits Pectin sugar acid are required to form a pectic gel see McGee p296 Carbohydrates other functions Some sugars are also precursors of color and flavor compounds Ex Caramel is produced when table sugar is heated at high temperatures Summary Carbohydrates some functions Supply energy some are dietary fiber components In Foods sweeteners moisture retention thickeners stabilizers gelling agents precursors of color and flavor Lecture 9 Main topics LIPIDS Include Fats Oils and other compounds cholesterol phospholipids waxes etc Fats are semisolids at room temperature Common sources are meat and dairy products ils are liquid at room temperature Ex cooking oils Lipids many roles Energy source 9 kcalg Energy storage they make up most of our fuel reserves Same for animals example in foods Marbling of meat USDA grading is based on fat distribution see McGee p 1368 Transport of fat soluble vitamins A D E K Major roles of fatsoluble vitamins Vit A vision Vit E antioxidant Vit D bone health Vit K blood clotting Supply essential fatty acids In foods sensory appeal texture flavor flavorful volatile compounds dissolve in fat heat transfer Lipids used as cooking medium Heat transfer with hot oilfat is called frying Basic structure of most lipids TRIGLYCERIDE TG Triacylglycerol TG are the most abundant lipids in the body and in foods TRIGLYCERIDE contain 3 FATTY ACIDS linked to a molecule of glycerol Fatty Acids chain of carbon atoms with a carboxyl group acid at one end Foods contain a mixture of fatty acids these differ in chain length generally from 4 C to 24 C atoms Most food fatty acids have an even number of C Fatty Acids differ in saturation Saturated Fat Unsaturated contain double bonds Monounsaturated one double bond Polyunsaturated 2 2 double bonds Essential Faty Acids Must come from foods Body needs but cannot synthesize them Two essential fatty acids Linoleic acid 18 C and 2 double bonds and alphaIinolenic acid 18 C and 3 double bonds Omega number indicates the position of a double bond counting from the methyl end on end of the fatty acid Linoleic acid is an m 6 fatty acid alphaLinolenic acid is an m 3 fatty acid Saturated Fatty Acids have a straight chain Double bond creates a kink in the chain see McGee p 799 Hydrogenation of oils addition of hydrogen to an unsaturated fatty acid Used to convert liquid oils into more solid fats Partial hydrogenation results in a mixture of products saturated and unsaturated fatty acids with cis and trans double bonds 39 H H trans CC I I clt5 H Hydrogenation increases shelf life and stability of fats during deepfrying It also allows production of fats with desired texture cis Major cause of lipid deterioration is OXIDATION Unsaturated fatty acids are susceptible to oxidation which leads to the formation of rancid odors To prevent oxidation appropriate packaging storage at low temperatures and in the dark use of antioxidants SMOKE POINT is the temperature at which lipids break down and produce visible fumes see McGee p 802 Lecture 10 Main topics Lipids cont Oil Refining removes undesired compounds Refined oil has higher smoke point than the correspondent unrefined source Trans Fat 0g on the label food contains less than 05 g of trans fats per serving Mayonnaise an emulsion a dispersion made with 2 immiscible liquids see McGee p626 Emulsifiers stabilize emulsions prevent droplets from aggregating Lecithin is a common emulsifier egg yolks contain lecithin see McGee p 802 PROTEINS Polymers formed by different building blocks amino acids Each protein has its own sequence of amino acids Proteins vary in size shape Proteins have many different biological functions Some Protein Functions in the body Structural bone skin hair nails MotorMechanical muscles Enzymes Antibodies Hormones ex insulin Transport ex hemoglobin Others Energy Amino Acids protein building blocks There are 20 amino acids commonly found in proteins Some are called essential amino acids these must be obtained from foods They cannot be made by the body or are made in insufficient amount to meet our needs One of the nonessential amino acids is glutamic acid lts sodium salt is monosodium glutamate or MSG see McGee p806 Peptide bonds join amino acids Dipeptide 2 amino acids Tripeptide 3 amino acids Oligopeptide a few amino acids Polypeptide many amino acids Polypeptide chains are linear see McGee p 806 Protein Structure 4 levels of organization primary secondary tertiary and quaternary structures Primary structure is the linear sequence of amino acids that forms the polypeptide chain It determines the folding of the protein and its final shape Even a single amino acid makes a difference ex sickle cell disease is an example of an inherited variation in the amino acid sequence Two major classes of proteins Globular are soluble in water most enzymes are globular proteins Fibrous insoluble in water they have structural roles ex collagen Collagen consists of 3 polypeptide chains that form a strong structure see McGee p 598 Foods and Protein Cooking Effect of heat and protein denaturation loss of 3dimensional structure of a protein see McGee p 808
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'