NUTR 211 - Final Learning Objectives

Describe "warmed over flavor" in poultry and its cause

"Warmer over flavor": - cause: lipid oxidation of unsaturated fatty acids - more prominent in dark meats ( because it contains more fatty acids to oxidize ) - more myoglobin in dark meat ( it is made up of iron and zinc- iron is a metal and another thing that can trigger lipid oxidation in fat) - Warmed-over flavor is an unpleasant characteristic usually associated with meat which has been cooked and then refrigerated. The deterioration of meat flavor is most noticeable upon reheating.

Describe the purpose of aging meat; differentiate between wet and dry aging

Aging meat: - holding meat for period of time - usually only in beef - increases tenderness, improves flavor and juiciness, better browning - enzymes Dry Aging: - hang carcass under refrigeration - 2 to 4 weeks - 34 to 38 F - 70% humidity Wet Aging: - packaging in vacuum bag under refrigeration; less shrink and trim loss

Describe the role of aging in cheese production; explain the impact of temperature and humidity on aging

when the cheese ages, the flavor intensifies due to the enzyme activity and moisture loss higher temperature: fast ripen higher humidity: more mold growth, low moisture loss for color

Describe how eggs are sized; define each egg size

- Egg size is related to the age of the hen - as the hen gets olde, she lays larger eggs - Eggs are sorted at the grading station based on weight, not circumference, and packaged accordingly into the following sizes. - Pee-Wee: 15 ounces - Small: 18 ounces - Medium: 21 ounces - Large: 24 ounces - X-Large: 27 ounces - Jumbo: 30 ounces * trend - all sizes differentiate by 3 ounces*

Explain food safety recommendations for storing fish and mollusks (shellfish)

- Finfish: use within a day or two of purchase; refrigerate tightly wrapped (reduce exposure to oxygen) - Live shellfish: use day bought; don't store in plastic bag; need air circulation; don't store in water -Target temperature: 145 F - Never leave seafood or other perishable food out of the refrigerator for more than 2 hours or for more than 1 hour if exposed to temperatures above 90°F.

Describe sensory outcomes from over mixing and under mixing a muffin batter (textbook reading) - not being tested on

- Overmixing batter can lead to tough muffins -Overmixing batter can inhibit that, ending with dense muffins instead of fluffy. This happens when you mix for too long. It can destroy air bubbles that are necessary for a light and airy texture - Overmixed muffins will have peaked, smooth-textured tops and long, tunnel-shaped air pockets in the interior, and will be tough in texture. - Undermixing An under- mixed muffin will have poor volume (because baking powder that has not been moistened remains inactive), some specks of dry flour, and will be crumbly.

Describe in detail the muffin method of mixing quick breads (textbook reading) - not being tested on

- The blending-method, also known as the muffin-method, combines the wet ingredients in one bowl and dry ingredients in a second bowl before mixing together. In addition to muffins, this method is used for preparing pancakes, crepes, and waffles.

Describe factors that affect the melting point of fats (melting points of individual fatty acids - chain length degree of unsaturation, position on glycerol, cisversus trans)

- The melting point of fats (ex: triglycerides) is influenced by the types of fatty acids and their relative positions on the glycerol backbone Factors that affect the melting point of fats: - Melting point increases, with and increase in carbon length of fatty acid - Melting point decreases ,with and increase in double bonds - Trans fatty acid higher melting point than cis counterpart - High melting point = solid at room temp = relatively high percent saturated fatty acids / trans fatty acids - Low melting point = liquid at room temp = relatively high percent unsaturated fatty acid

Explain FDA-approved methods of reducing pathogens in poultry

- chill carcass in chlorinated water - drip carcass in trisodium phsphate (TSP) as an antimicrobial agent - irradiate (exposure to radiation) to treat uncooked poultry to reduce pathogenic bacteria

Explain how poultry is classified for the market and describe the most common chicken classes (broiler/fryer, roaster, Cornish game hen - see class handout)

- classified primarily to age and weight; some by gender - age affects tenderness (connective tissue) and fat content Common chicken market classes: - broiler/fryer: <13 weeks (although most sold in retail markets are 6-8 weeks old), most commonly found chicken in conventional supermarkets - roaster: 3-5 months, > 7 pounds - cornish game hens: different breed cross, 5-6, <2 or equal to 2 pounds - mature chickens: > 20 months; best for moist-heat preparation/stewing; lots of flavor due to increasing collagen

Describe colloidal systems; describe a foam

- colloidal system: ( two phase system : one substance of a certain size) dispersed in another - the two substances can be solid, liquid or gas - all colloidal systems have a continuous phase and a discontinuous (dispersed) phase - a foam is a colloidal system where a gas is dispersed ( discontinuous phase) in a liquid ( continuous phase)

Describe what causes the "fishy" smell of some fish

- when fish are killed, bacteria and fish enzymes convert TMAO into trimethylamine (TMA), which gives off the characteristic "fishy" odor. - TMA on the surface of the fish can be rinsed off with tap water

Name foaming agents in milk, cream and eggs

-Milk: milk proteins; trap air, fat, and liquid. -Cream: fat -eggs: egg whites and egg proteins -gelatin

Describe how the following factors affect the stability of cream foams: fat content, age, temperature, sugar

-fat content: fat stabilizes (forms film around air). More fat = more stable -temperature: saturated fat must be solid, so best to use cold cream -age: older cream has undergone evaporation, more viscous, more stable. -sugar: enhances viscosity and stability since its hygroscopic, so it binds to water.

Differentiate between types of wheat flour based on protein content; identify appropriate uses for each type of wheat flour; describe the effects of using whole wheat flour on the sensory characteristics of the end product in baking

Bread Flour: 12-14% gluten, used in production of yeast breads All-Purpose Flour: 11% gluten, less protein than bread flour, blend of hard and soft, breads, cakes, pastry Pastry Flour: 9% gluten, soft wheat, pastries, cakes, rich yeast doughs, quick breads Cake Flour: 8%, fine grain, smooth textured cakes, bleached to improve color and baking quality Soft Wheat: - less protein, more starch, less gluten development - better for cakes, pastry - more tender product is more desired Hard Wheat: - more protein, less starch, more gluten development - better for yeast breads Whole Wheat Flour (graham flour): - whole wheat kernel - bran cuts gluten strands (negatively impacts volume) - refrigerate/ freeze to prevent oxidative rancidity - not much leavening will occur - increased intensity of flavour, aftertaste and also pungent flavour of bread

Identify the two primary milk proteins; explain the effect of acid and heat on each

Caesin Protein: - found in micellular proteins - large, complex molecules of various forms of casein and calcium, phosphate, and citrate - micellular proteins are colloidally dispersed in milk, gives characteristic "whiteness" of milk - casein is sensitive to acid - isoelectric point of casein 4.6 at this pH, casein micelle aggregate - heating - Casein proteins are heat-stable, but will denature below pH 4.6. Whey Protein: - 100% whey protein denatures and precipitates at 158 F - whey proteins scorch easily - heat will cause whey proteins to denature -

Describe labeling of eggs (cage-free, free-range, etc.)

Cage- Free: - cage-free hens are able to walk, spread their wings and lay their eggs in nests, vital natural behaviors denied to hens confined in cages. Most cage-free hens live in very large flocks that can consist of many thousands of hens who never go outside. Free- Range/ pasture raised: - Free-range, another USDA term, means that the eggs come from hens that have some sort of access to the outdoors. - are produced by hens raised outdoors or with access to outdoors. In addition to the feed provided, these hens may also eat wild plants and insects. Omega-3 FA enriched: - add flax, EPA & DHA rich algae to hen ration/food High vitamin E eggs: - add high vitamin E foods to hens

Describe the connective tissue proteins (collagen and elastin) in animal muscle meats; compare/contrast collagen and elastin's response to heat and moisture

Collagen: - most abundant muscle tissue - more collagen is found in areas with a higher concentration of connective tissue ( areas of more movement/exercise in the animals body) Elastin: - found primarily in the neck, shoulders, rump of land mammals (ex: beef, pork, sheep) - aka silver skin Response to heat and moisture: Collagen: - When heated with moisture, hydrolyzed into gelatin, which increases tenderness in less tender cuts of meat Elastin: - changes minimally when exposed to heat - when heated it becomes rubbery, shrinks, and becomes tougher) - cut out or mechanically tenderize to enhance tenderness

Explain the rationale for recommended temperature differences between cream foams and egg white foams

Cream foams : - At higher temperature, the liquid phase viscosity decreases, which can potentially have a detrimental effect on foam formation. Egg white foams: - egg proteins have lowest surface tension at room temperature, so that will enhance stability and volume

Define emulsion and emulsifier; differentiate between an oil-in-water and a water-in-oil emulsion and give an example of each; describe the two phases of an emulsion; describe what the interface of an emulsion is and how emulsifiers affect it

Emulsion: - Two phases of an emulsion -Dispersed or discontinuous phase (ex in butter water is dispersed) -Dispersion or continuous phase (what is doing the suspending / in butter, the fat is the dispersion) Emulsifier: - Emulsifiers act as stabilizers - Stabilizers helps keep one phase dispersed in the other by acting as surfactants at the interface - Surfactants: wetting agents that reduce surface tension, which makes easier to mix phases Emulsifiers: - Amphiphilic: attracted to both water and fat - hydrophilic/polar: "water-loving" - lipophilic/nonpolar: "lipid-loving" Oil- in water: - When an emulsion is "oil-in-water," oil is the dispersed phase that is distributed into the continuous phase, water. Water- in-oil: - Water-in-oil (W/O) emulsions consist of an aqueous phase dispersed, in the form of small droplets, into a continuous oil phase Two phases of emulsion: - dispersed or discontinous phase - dispersion or continuous phase Interface: the boundary between the discontinuous and continuous phase

Explain differences between the coagulation of milk for cheese curd using acid or enzymes; describe differences between these cheeses and their nutritive value based on method of coagulation

Enzyme assisted: we add lactic acid producing bacteria which consumes lactose and creates lactic acid that lowers the pH Rennin will act in acidic pH with casein to create a rougher curd, calcium remains ACID: no enzymes: lose calcium in whey higher moisture, soft, demineralized

Identify factors that affect the coagulation temperature of proteins in eggs; describe specific cooking applications where these changes would be desirable

Factors that affect coagulation temperature of proteins in eggs: - heat: protein denaturation Cooking application: frying eggs - mechanical (beating or chipping) Ex: baking and wanting to reach stiff peaks - to form meringues - sugar (rises temperature for coagulation) Ex: when you want eggs to foam and form stiff peaks (less stable) - acids (decrease temperature when coagulation is achieved ) Ex: decrease pH and will cause foam to be more stable, acts as a stabilizer to stabilize cross-linking of proteins - alkali (high alkalinity can induce gelling of egg white) Adding ingredients can change coagulation temperature of egg proteins: - sugar increases coagulation temperature - salt/acid decreases coagulation temperature

Describe how the composition of the muscle and connective tissue proteins in fish differ from meat and poultry

Fish composition of muscle and connective tissue: Structure: - less collagen than red meat and poultry Amino Acids: - less hydroxyproline ( means more amino acids) in connective tissue of fish - fish will hydrolyze at a lower temperature in comparison to meat because it contains (140 F) less hydroxyproline Muscle Structure: - shorter myofibrils; this is why most fish flakes

Differentiate between factors that affect cream foam stability compared to milk foam stability

Foam: -milk foams are produced with steam, since heat unfolds proteins around air bubbles -higher fat content will destabilize foam since the fat will melt and aggregate. -low fat milk for more stable foams Stability: -whisking breaks links between proteins, denatures structure and forms film around air cells -egg proteins conalbumin and ovalbumin help form foam films, ovamucin enhances viscosity and stability -egg whites reduce surface tension, enhancing stability

Explain FDA guidelines for using pasteurized milk in the production of cheese in the United States

Fresh and soft cheese: FDA requires using pasteurized milkHard cheeses: FDA requires cheeses that are made with raw milk to be aged a min 60 days

Describe labeling terminology for poultry labeling based on holding/chilling temperatures; describe requirements for labeling based on percent water retained

Fresh vs Frozen: - Fresh: never below 26 F - Hard-Chilled: held below 26 F but above 0 F - Frozen: held at 0 F or below Percent water retained: - result of washing carcass, chilling, post- slaughter processing - The permitted labeling variation is 20 percent from the declared amount within the retained water statement.

Compare the general nutrient profile of fluid milk and cheese

General profile of fluid milk vs cheese: - Cheese has a similar nutrient profile to milk, but in a concentrated form - calcium content depends on method of coagulation - higher sodium - easier to digest - less lactose

Distinguish between hard and soft meringues; describe problems that can occur when making meringues and possible solutions

Hard Meringues: - cooked at a lower temperature but for a longer time Soft Meringues: - lower percentage of sugar, cooked at a higher temperature for a lower period of time Problems that occur when making meringues: - Shrinking: prevent by overlapping onto pie crust - Weeping (syneresis): caused by under beating or meringue con cold filling - Breading: caused by undissolved sugar and overcooking Solutions: - Don't use packages egg whites - Use eggs at room temperature - Don't add yolk to egg whites - Do not over beat - can be checked through stiff peaks

Describe the process and purpose of homogenization; describe changes to milk as a result of homogenization

Homogenization: - mechanical process that prevents the separation of water and fat that prevents creaming - prevents creaming from happening - forces milk through small openings and breaks up the fat globules Changes to milk as a result of homogenization: - whiter - coagulates easier - greater foaming capacity - more prone to rancidity

Describe inspection and grading of eggs; identify egg quality grades and characteristics of grade AA egg versus those of inferior quality

Inspection: - the process of evaluating the quality of food products as well as the methods, equipment, and environment where the food is stored and prepared fro public consumption Inspection of eggs: - egg shells are inspected for cleanliness, texture, lack of cracks, and shape - small probes tap an egg multiple times and record the sound thats made - a high pitched eggshell is intact, while a thump indicates a crack Grading: - There are three consumer grades for eggs: Grade AA, A, B - Grading is determined by the interior quality of the egg and the appearance and condition of the egg shell - Eggs of any quality grade may differ in weight (size) Grade AA: - the freshest and highest quality eggs will receive - albumin is thick and firm - yolks are high, round, and practically free from defects - clean from unbroken shells Grade A: Very high quality eggs Grade B: Eggs usually used for breaking stock (liquid eggs) and baking, depending on the number of defects * Grade A and AA are best for frying and poaching where appearance is important, and for any purpose*

Describe the nutrient profile of dairy milk; compare the general nutrient profile of fluid milk and cheese; contrast differences between dairy milk and non-dairy alternatives

Nutrient profile of dairy milk: - 87%: water - 13%: milk solids, fat, milk solids non-fat, protein, lactose, minerals, casein, whey proteins General profile of fluid milk vs cheese: - Cheese has a similar nutrient profile to milk, but in a concentrated form - calcium content depends on method of coagulation - higher sodium - easier to digest - less lactose than milk Differences between dairy and non-dairy alternatives: - Non-Dairy milk alternatives can be substituted in most recipes if the purpose of the dairy milk is as a source of liquid - If the protein component of milk is required, then most non-dairy alternatives are not equivalent substitutes

Describe the source, how it's produced, and general fatty acid composition (saturated, unsaturated, trans fat, etc.) of the following fats: lard, butter, vegetable oils, vegetable shortening

Lard (swine fat) : Source: swine How its produced: - fat must be extracted by rendering - commercially prepared, lard is processed (to improve texture), deodorized and has added antioxidants - For baked goods, lard has excellent shortening power Fatty acid composition: saturated fat Butter: Source: comes from cream of milk Composition: 80% milk fat, 16% water, 4% milk solids - milk is an oil-in-water emulsion = butter is a water-in-oil emulsion How its produced: phospholipids surround fat globules in milk agitation breaks phospholipid membranes = fat globules coalesce butter - churning cream until the fats separate from the liquid (buttermilk) and the butter is in a semi-solid state. Fatty acid composition: saturated Vegetable Oils: Source: - source of cooking and salad oils, margarine, and shortening - Vegetable oils primarily from soybeans, rapeseed, sunflower seed, corn, cottonseed, avocado, palm kernel, olive How its produced: - Mechanical: cold-pressed vs hot-pressed - Chemical: uses solvents to extract pressed seeds to increase yield Fatty Acid Composition: saturated fatty acids, monounsaturated fatty acids Vegetable Shortening: Role: - Increase solidity and increase pliability than un-hydrogenated oils - Neutral flavor, high smoke point (good for frying), tenderize cakes/pastry by shortening gluten strands Source: - typically made from hydrogenated and partially hydrogenated vegetable oils, such as corn, cottonseed or soybean. How its produced: - hydrogenating (adding hydrogen to) vegetable oil, such as soybean or cottonseed oil Fatty acid composition: - saturated - polyunsaturated - monounsaturated

Differentiate between mechanical and chemical extraction of vegetable oils

Mechanical Extraction: - Cold-pressed vs. Hot-pressed - pressing alone does not remove all the oil from the seed Chemical Extraction: - uses solvents to extract pressed seeds to increase yield - uses a solvent to remove the remaining oil that mechanical press cannot

Explain the basis for milk grades; describe the process and goals of pasteurization; explain the time and temperature requirements for LTLT, HTST, and UHT pasteurization

Milk grades: - grading of milk is ranked on bacterial count; indication of sanitary conditions at time of milking - Grade A most common - For milk to be transported across state lines (interstate commerce), it must be grade A certified - Raw milk is illegal to sell across state lines Milk Grades: - Grade A and Grade B - Grade A: milk produced under sufficiently sanitary conditions to qualify for fluid consumption - Grade B: this milk does not meet fluid grade standards and can only be used in cheese, butter, and nonfat dry milk Process and goals of pasteurization: - pasteurization kills all pathogenic bacteria - it inactivates spoilage enzymes that reduce shelf life - does not mean sterilization LTLT: (long temperature, long time) - Time: 30 min - Temperature: 145 F HTST: (high temperature, short time) - Time: 15 sec - Temperature: 161 F UHT: (higher heat, shorter time) - Time: 0.01 sec - Temperature: 212 F UHT: (ultra high temperature) - for aseptic packaging 280-302 F, 2-6 seconds

Define myoglobin and its effect on meat color; explain how exercise, age, gender, and species affect the amount of myoglobin in meat; differentiate between myoglobin, oxymyoglobin and metmyoglobin

Myoglobin: - color of muslce meats comes primarily from myoglobin (90%) - myoglobin and hemoglobin shave a similar strucutre - most hemoglobin removed with blood myoglobin increases with exercise - myoglobin differs on species of the animal -is the heme iron containing protein that gives meat its color, and it is a great source of dietary iron. Myoglobin stores oxygen in muscle cells and is similar to hemoglobin that stores oxygen in blood cells. Oxymyoglobin: - bright red - Exposed to oxygen, myoglobin oxygenated, becomes oxymyoglobin (bright red) metmyoglobin: - brown - Further oxidized, oxymyoglobin becomes metmyoglobin (brown) Effect of myoglobin on meat color: - Myoglobin changes with oxidation and changes perception - The more myoglobin content meat contains the darker red it will appear in color Exercise, age, gender, and species effect on amount of myoglobin in meat: - myoglobin increases with age - myoglobin increases with exercise - myoglobin is higher in beef and lamb in comparison to poultry

Name common non-wheat grain-based flours and non-grain flours used in baking (textbook reading) - not being tested on

Non grain flours: - Almond Flour - Arrowroot Flour - Cassava Flour - Chickpea Flour Non wheat grain based flours: - Amaranth Flour - Buckwheat Flour - Flaxseed Flour - Quinoa Flour

Explain the process of oxidative rancidity of a fat; describe consumer and commercial methods to prevent oxidative rancidity, including their mechanism of prevention

Oxidative rancidity: known as autoxidation, occurs when oxygen is absorbed from the environment. In the presence of oxygen and/or ultraviolet (UV) radiation, most lipids will break down and degrade, forming several other compounds. - Oxidative rancidity is a reaction of fatty acids with oxygen. More specifically it is the reaction of double bonds in unsaturated fatty acids with oxygen - a reaction of the triglycerides with oxygen Preventing oxidative rancidity: - The first way to prevent rancidity is to eliminate oxygen. Think of vacuum packaging a product. - Prevent using unsaturated fatty acids, saturated ones won't oxidize. Mechanism: Oxidative rancidity is a chemical reaction catalyzed by heat, ultraviolet light, heavy metals and oxygen. Many of these factors are obviously present during the extrusion process. Oxidative rancidity is best controlled by the addition of antioxidants and 'oxygen scavengers'.

Describe the role of salt in cheese making

PURPOSE: dehydrate the curds control microbial growth and rate of ripening add flavor

Define plasticity as it relates to fats; identify how plasticity of fat influences performance; describe the function of plastic fats in food preparation ("creaming")

Plasticity: - The ability of a solid fat to be molded or shaped How plasticity (of fat) influences performance: - The type and size of fat crystals influence consistency and performance of fat - Consistency of fat determined by: 1.) ratio of solid: liquid fat, fatty acid composition, temperature of fat - performance of fat impacted by consistency; 1.) spreadability, 2.) creaming Function of plastic fats in preparation: - aids in aeration of batters and doughs which contributes to leavening and "lightness: in baked products - (Plastic fat "creamed" with sugar) - (Sugar crystals cut into solid fat and create air cells) - (Air cells expand when batter/dough heated) Examples of plastic fats: butter, lard, ans shortening

Describe the differences between a pour batter, a drop batter, and a dough (textbook reading) - not being tested on

Pour Batter: - Pour batters have a fluid consistency and are pourable. Unlike a drop batter, pour batters run when dropped from a spoon. Typically, pour batters have a one-to-one liquid-to-flour ratio. Drop Batter: - batter of such consistency as to drop from a bowl or spoon without running usually made in a proportion of two parts flour to one part liquid compare pour batter Dough: - mixture of flour and liquid with other ingredients, such as leavening agents, shortening, sugar, salt, eggs, and various flavourings, used to make baked products. A similar mixture, in more liquefied form, is known as batter. Doughs are thick and plastic and may be shaped, kneaded, and rolled.

Describe the process of hydrogenation and its purpose in the food industry; contrast hydrogenated and partially hydrogenated shortening

Process of hydrogenation: - hydrogen gas bubbled through vegetable oil in presence of nickel catalyst under pressure and heat Purpose in the food Industry (for vegetable oils) : - Increases stability to heat by increasing melting point - Increases shelf life of mono and polyunsaturated fats - Alters texture - Increases saturation of fat, increases melting point Hydrogenated shortening: - partial hydrogenation creates trans-fats Partially hydrogenated shortening: - while fully hydrogenated, the oil returns to a "zero trans-fat" level.

Describe the purpose of energy in creating a foam; describe the role of surface tension in creating foams

Purpose of energy in creating foam: 1.) overcome surface tension in the liquid phase - liquid have a low surface tension to form foams or have added foaming agents 2.) stretch liquid into thin films around air bubbles ( gas phase) - low surface tension increases foam stability, as does the addition of solids that can provide rigidity to the film

Explain practices for the safe storage of eggs and techniques to prevent food borne illness when cooking with eggs

Safe storage: - refrigerator temperatures ( <40F) - Don't wash, keep in carton for moisture - Don't store in refrigerator door - Storage for 4-5 weeks after pack date Food Safety with eggs: - Salmonella Enteritidis - internal contamination: in ovary of hen - external contamination: fecal contamination - Eggs: source of > 73% salmonella outbreaks - listeria monocytogenes Mechanisms to promote safe egg consumption: - use egg separator - refrigerator storage - avoid raw egg consumption - pasteurized eggs - cooking temperature Techniques to prevent food borne illness when cooking:

Describe inspection and grading of red meats, poultry, and fish; differentiate between quality and yield grades in red meats

Red Meat Inspection and Grading: - Grading: voluntary; USDA administers, meat packer/processor pays for quality and yield / quality grades of red meats: prime, select, choice, standard and commercial, utility, cutter, canner - Inspection: meat inspectors identify meats as : healthy ( no disease), sound (clean, sanitary), wholesome (not adulterated), properly labeled (it is what is says it is). Detection and destruction of diseased meat and or contaminated meat. Minimization of microbiological contamination of meat. Poultry Inspection and Grading: - Inspection: Examination, trimming, washing, and chilling - Grading: The US consumer grades for poultry are Grades A,B, C. Grading involves evaluating poultry in terms of the standards to determine the grade. Fish Inspection and Grading: - Inspection: fish should be clean and free from all deterioration and spoilage, the fish should not have any foreign odors or smell of deterioration or spoilage - Grading: fish is graded by size (which can be done by hand or my a mechanical grader), after size color of the fish is graded Quality in Red Meats: - for tenderness, juiciness, and flavor - amount of marbling, color, and maturity - Ex: prime, choice, select, standard and commercial, and utility, cutter, canner Yield Grades in Red Meats: - amount of usable lean meat on the carcass Shellfish: - Live shellfish: use day bought; don't store in plastic bag; need air circulation; don't store in water

Describe the role of gluten in wheat (and rye and barley) flour mixtures; describe the two proteins responsible for gluten formation in wheat flours; identify the third component necessary for gluten formation in wheat flour mixtures

Role of Gluten in Wheat: - Water soluble and insoluble fractions in flour - gluten is not naturally found in nature, we make it with two water insoluble proteins - water is needed for the formation of a gluten matrix - gives ability to expand with inner pressure from leavening gasses (once matrix has already been formed) - if not leavening gasses will just be released into the atmosphere -contributes to the firming of flour mixtures - ability to rise related to amount of gluten in flour - when heated proteins coagulate Role of Gluten in Rye : - only have prolamins (secalin), you do not have glutenins - 100% rye bread will give you a very dense consistency because your crumb is totally made from a starch matrix, not gluten Role of Gluten in Barley : - only have prolamins (hordein), you do not have glutenins Two proteins responsible for gluten formation: - Water insoluble proteins 1.) gliadin 2.) glutenin - gliadin + glutenin + water = gluten matrix Third component necessary for gluten formation: 3.) Water - it is necessary to form the gluten, if not it is just gliadin and glutenin in its solid state

Describe the role of hydration and physical manipulation (e.g. stirring, beating, kneading) in formation of the gluten matrix

Role of Hydration: - Gluten thrives on hydration. While dough is in the mixer, water molecules are binding to the polar sites on the gluten proteins. When these proteins have enough water, they provide elastic and extensible (leavening) properties. In other words, the better hydrated gluten is, the better it will function in your baked goods. Physical Manipulation: - will be used to manipulate the structure of the gluten matrix due to the amount of hydration that was present Kneading: - stretching and folding the dough forms pockets that are stretched when gases expand

Explain the role of connective tissue in the structure of meat muscle; describe factors that affect the amount of connective tissue in meat (age, muscles used for movement); name techniques for tenderizing meat; describe cooking methods more conducive to producing a tender product based on amount of connective tissue in the cut

Role of connective tissue: - binds individual cell and bundles of cells together - more development in muscles used for movement - directly determines tenderness of meat Factors that affect the amount of connective tissue: - exercise + movement - muscle position in the carcass - animal age Techniques for tenderizing meat: - When heated with moisture, hydrolyzed into gelatin, which increases tenderness in less tender cuts of meat - Mechanical: grinding or cubing to break up connective tissue - Acids: break down surfaces of meat; contribute to flavor - Enzymatic: proteases that hydrolyze surface proteins (enzymes from papaya, pineapple, etc.) Cooking methods more conductive to produce a tender product: - Dry heat methods of cooking are suitable for tender cuts of meat or less tender cuts which have been marinated. Dry heat methods include roasting, oven broiling, grilling, pan-broiling, panfrying and stir—frying. Factors that affect real of perceived tenderness: - Myofibrillar proteins - Collagen proteins - Fat and marbling: more marbling, sensory perception of greater tendernes

Summarize safe storage and handling of muscle meats including proper thawing and cooking temperatures

Safe storage and handling of muscle meats: Safe storage: - Store fresh muscle meats refrigerated below 40F or frozen - Minimum safe cooking temperatures for red meats Handling: - Ground beef (and red meat products that have been punctured , mechanically tenderized) - 160 F for home cooks - fresh whole breed, veal, lamb, pork, and ham: 145 F with 3 minute rest - cook poultry to 165 F ( if stuffed - not recommended- stuffing must be cooked to 165) Red Meat: - temperature: 28 to 32 F - meat should be stored in the coldest part of the refrigerator - as storage temperatures approach 40F perishability increases - rapid growth of bacteria begins at about 50 F Fish: - target temperature: 45 F - should be used within 2 days after purchase otherwise wrap it tightly in plastic, foil, or moisture-proof paper and store it in the freezer Poultry: - Refrigerated poultry at <40 F for up to three days - Frozen for 6-12 months is raw; 4 months if leftover cooked Proper thawing: - When thawing frozen food, it's best to plan ahead and thaw in the refrigerator where it will remain at a safe, constant temperature — at 40 °F or below. There are three safe ways to thaw food: in the refrigerator, in cold water, and in the microwave. - refrigerator thawing, cold water thawing, microwave thawing, cooking without thawing

Define smoke-point of fats/oils

Smoke Point: The smoke point, also referred to as the burning point, is the temperature at which an oil or fat begins to produce a continuous bluish smoke that becomes clearly visible, dependent upon specific and defined conditions.

Contrast what provides stability in a cream foam versus an egg white foam; describe factors that enhance or interfere with stable egg white foam formation

Stability in cream foam: -fat content: fat stabilizes (forms film around air). More fat = more stable -temperature: saturated fat must be solid, so best to use cold cream -age: older cream has undergone evaporation, more viscous, more stable. -sugar: enhances viscosity and stability since its hygroscopic, so it binds to water. Stability in egg white foam - over whipping results in dry foam, not stable - if room temperature decreases, surface tension will increase in volume and stability Factors that enhance or interfere: -sugar: enhances stability bc hygroscopic -fluid: enhances volume, but reduces stability because proteins are diluted -salt: increases surface tension, decreasing stability -acid: enhances stability by destabilizing egg proteins, helping them unfold earlier. Also neutralizes negative charge on proteins so they can bond more together

Define standards of identity for various milk products (see handout on Canvas)

Standards of identity: defines food products, their names, and ingredients that must be used in production in order to call a food by a specified name Standards of identity for various milk products: - Fluid Milk - Specialty Milks - Canned Milks - Sweetened condensed miilk - Dry milk - Cultured milk products - creams Fluid Milk: - whole milk - reduced-fat/low fat - fat free/ nonfat Specialty milks: - imitation milk - filled milk - organic milk Canned milks: - evaporated milk - sweetened condensed milk Dry Milk: - non-fat dried milk Cultured milk products: - Buttermilk - Yogurt - Acdophilius milk - Sour Cream - Creme fraiche Creams: - half and half - light cream - light whipping cream - heavy cream

Identify and describe the structure of eggs (the five primary parts: composition, nutrient profile, defense mechanisms, etc.)

Structure of eggs: - Yolk - Albumin Shell membrane - Air Cells (creates separation of shell membranes and temperature change ) - Shell Yolk: - rich in phospholipids (lipoproteins), fat-soluble vitamins, cholesterol , iron Color of yolk depends on hens diet - eggs are rich in choline - yolk is surrounded by vitelline membrane - an egg yolk is a naturally occurring oil in water emulsion - It makes up about 33% of the liquid weight of the egg and is formed in the ovary Shell: - color of egg shell does not determine the value or quality of food - The eggs outer covering, accounts for about 9 to 12 % of its total weight depending on egg size Eggs have a porous shell - they have a porous shell to exchange moisture and gases What is the shell covered in? - The shell is covered in bloom which prevents excessive lost and protects contents - protects eggs from any bacteria getting in Inner membrane: - contracts which leaves air space in large end Albumin (egg white): - accounts for most of an egg's liquid weight, about 67%. This is produced by the oviduct and consists of four alternating layers of thick and thin consistencies. - primarily water and protein -Vitamin b12, riboflavin, biotin, selenium, iodide, zinc Air Space: - this is the empty space between the white and shell at the large end of the egg which is barely existent in newly laid egg. Chalaza: This is the ropey strands of egg white at both sides of the egg, which anchor the yolk in place in the center of the thick white. Germinal Disc: - This is the entrance of the latebra, the channel leading to the center of the yolk - this is where a females genetic material is found Vitteline Membrane: It is the covering that protects the yolk from breaking Defense mechanisms of eggs: The physical defense against bacteria invasion is accomplished by eggshell, together with the cuticle and membranes. The chemical defense consists of proteins that exhibit antimicrobial activity and are mainly present in albumen and to a lesser extent in yolk and shell. Shell membranes: - the thin membrane on the inside of an eggshell. Its prime constituent is protein and it has a two layered, reticulated structures. The exterior is rough, while the interior structure is dense.a

Differentiate between "trimmable" fat and "marbling"

Trimmable fat: - subcutaneous fat (fat found under the skin) Marbling: - intramuscular fat ( fat cells deposited between mammals) - marbling is most associated with red meats - visible intramuscular fat between the muscle fiber bundles - marbling is thought to be correlated to tenderness of red meat but not strongl y - marbling does not contribute to juiceiness

Describe factors that affect emulsion stability

What affects emulsion stability? - surfactants: wetting agents that reduce surface tension, which makes easier to mix phases - surface tension:: attractive-properties at surface of a liquid Stability of emulsions: Things you can do to decrease the stability of an emulsion: - excessive agitation - long storage times (permanent emulsions) - extreme temperatures

Name the prolamins in wheat, rye, barley, and oats; describe the significance of these proteins for health of susceptible individuals

Wheat: Gliadin Rye: Secalin Barley:Hordein Oats: Avenin Significant: Prolamins are what people who have celiac disease of gluten insensitive react to. Prolamins are not all the same. *a person is not intolerant of allergic to the gluten as a whole, but more precisely to one of the proteins. Some people respond well to avenin, but at times it can be exposed to cross contamination in the industry*

Describe processes to remove whey from cheese curd

Whey is separated from the curds REMOVE MORE WHEY: cutting to increase surface area COOKING / Heating to evaporate the whey - Acidifying (souring) milk helps to separate the curds and whey and control the growth of undesirable bacteria in cheese.

Explain the cause of the green layer that can occur around the egg yolk of a hard-cooked egg; identify methods to prevent the formation of this sensory outcome

Why does green layer occur? The green ring around the yolk of a hard cooked egg happens because hydrogen in the egg white combines with sulfur in the yolk. The cause is most often related to boiling the eggs too hard for too long. The green ring can also be caused by a high amount of iron in the cooking water. How to eliminate: - Eliminate the ring by avoiding overcooking and by cooling the eggs quickly after cooking. Run cold water over the just-cooked eggs or place them in a bowl or container of ice water until they have completely cooled. Then refrigerate the eggs in their shells until you're ready to use them. - Iron in egg yolk can form ferrous sulfide in presence of high temperature/long cook time = green ring around yolk

Explain why milk is an emulsion; describe the phenomenon of "creaming" as it pertains to milk

Why is milk an emulsion: - Milk is an emulsion in which milk fat is dispersed in water. Emulsions are colloids in which both dispersed phase and dispersion medium are liquids. So, milk is an emulsion in which liquid is dispersed in water. - liquid in oil dispersion "creaming" as it pertains to milk: - a natural process that occurs during the storage of raw whole milk. Due to the differences in densities between fat globules and the plasma phase of milk, fat globules tend to accumulate as a cream layer on top of the milk. However, natural creaming of fat highly depends on the storage temperature of milk. - the process by which cream rises to the top of un-homogenized milk

Describe factors that affect the cooking quality of cheeses

temperature: lower temp is better, prevents toughening and oil separation time: shorter the better acid: coagulation, separation alcohol: less curdling decreases boiling point