Chap 8 Flashcards
(37 cards)
Industry - Eggs are used for
Foaming(6-8times volume,soufflé, meringue,sponge cake, use fresh eggs for thicker white, based on temperature, type of bowl, addition of salt, acid, sugar), thickening, emulsifying (egg yolk contains lecithin), leavening, colouring, glazing, coating, binding (meatballs, muffins, battered foods).
EGGS- Structure
Yolk- 1/3weight, proteins, nourish the chick, colour depends on hen’s diet (beta-carotene)
Albumen: 58% weight, water and protein
Chalaza: anchors egg yolk to center of white
Shell: calcium carbonate shell, 12% weight, not solid, contains thousands of tiny pores for gas exchange
Air cell: pocket of air, when egg is laid, the content contracts and 2 shell membranes separate. Provides air to breath for chick. (fresher egg smaller circle)
Shell membrane: Between egg white and shell, protects from bacterial invasion
NV - Eggs
Proteins:7g, mostly ovalbumine(54%,denatures easily become white). Avidine(0,05%, binds the vitamin b, raw egg white only)
Fat: Mostly triglyceride 55%(MUPA), cholesterol 5%
Vitamins: a,d,e,k, b2,b9,b5,biotin
Minerals: selenium,iodine, iron(not bioavailable), zinc, copper, choline
Pigments - EGGS
Carotenoids: lycopene, lutein, xanthophyll, zeaxanthin
Eggs - Cooking methods
Moist heat: Microwave, boiling, coddling, poaching, custard
Dry heat: scrambled, fried,omelets,baking
Safety tips for Eggs
- internal contamination is rare, look out for external contamination, more common during handling and preparation, salmonella on the outside
- Listeria monocytogene can grow in fridge
Egg replacers, why and how
Vegan, cholesterol protein restricted diet, egg allergy.
1tbspChia seeds + 1/3cup water, 1/4cup silken tofu, 1/2banana.
Definition - Milk
White yellowish liquid secreted from the mammary gland to serve as nutrition for the newborn
NV of Milk
Water(88%)
Vit B2(riboflavin), A, D, calcium (P, K, Mg, S), proteins,
fat (contributes to mouthfeel, flavour, chemical properties/stability of product). Mostly saturated(66%).
Carbohydrate: lactose, transformed into lactic acid by lactase. Lactose intolerant ppl don’t have lactase. worse for milk than fermented products. (7million canada)
Fat found both in EGGS and MILK
triglycerides, phosphoglycerolipids, cholesterol
Levels of fat MILK
Skim milk, buttermilk, 1%milk, whole milk.
Proteins in MILK
Casein:80%protein in milk.composite of a,b,g,y casein. Precipitated by enzymes or acids. Added to food to improve NV.
Whey:Lactalbumin, lactoglobulin. Liquid portion after cheese making. Isolated and used as emulsifiers or improve NV. Improves mouthfeel, flavor, moisture retention.
Milk allergy
3-5%, related to B-lactoglobulin, symptoms: vomiting, abdominal pain, nausea, skin rash, headache
MILK- Canada food guide recommends
1cup milk, 1cup fortified soy milk, 1/2 canned evaporated milk, 3/4cup yogurt/kefir, 50g cheese. 2 portions a day. Milk alternatives: soy milk and pea enough proteins, soy and hemp interesting alternatives. MILK: 20-30% calcium, b12, vit d daily value.
Production process : Pasteurization
Regular: Heating milk below its boiling point for a short amount of time to reduce foodborne illnesses. kills 100% pathogenic, 95%non-pathogenic. To ensure adequacy, food processors measure alkaline phosphatase activity, an enzyme found in milk.
Ultra: higher temp for shorter time, 15 seconds. extend shelf lime
Ultra high temperature (UHT): 2 seconds,sterile packaging techniques, can be stored unrefrigerated 3 months.
Production process: Homogenization
Breaks up fat globules into smaller globules that do not clump together and are permanently dispersed in an emulsion. Coagulates quicker in presence of heat (pudding, white sauce, cocoa)
Cheese making, steps
Milk selection, coagulation (rennins), curd treatment, curing and ripening.
Coagulation - Milk products
Acid: decreasing ph= more compact, solid. 50% Ca lost in whey, not aged too acidic
1. Inoculate milk with bacterial starter culture (4-16hours) Lactose converted to lactic acid.
2. add acid.
Enzyme: Tougher, different bacteria, enzymes, yeast, mold will affect texture, flavor, color.
1. Chymosin: digestive enzyme originally found in stomach lining of milk-fed calves. AKA rennins/rennet. Cuts K-casein.
2. Enzymes from GMO bacteria
3. Enzymes derived from vegetables and bacteria= coagulants.
Curding - Milk products
Curd is treated to remove more whey.
- Cutting: Increase surface area, then strained. low moisture varieties= smaller curds
- Heating: Increase evaporation for a firmer texture and destroys microorganisms. 3. Salting: Dehydrates, controls bacterial growth, flavour, texture, appearance
- Knitting: Curds are melted into a solid mass(optional)
- Pressing: Curds are pressed into a mass (optional).
Curing and Ripening - Milk products
Curing: Aging of cheese in controlled conditions of temperature and humidity.
Ripening: Chemical and physical changes during curing, glycolysis, lipolysis, proteolysis. 4 weeks to 2 years. Salts, bacterias, mold are manipulated to vary texture, flavor, aroma.
NV of Cheese
Protein: complete
Carbohydrate: lactose drained off in whey, little!
Fat: Saturated, responsible for flavor, satiety, texture.
Cholesterol = 25 mg per ounce
Vitamins: fat soluble (a,d). Water soluble are drained off.
Minerals: Ca, P, Z
Properties of cheese during Cooking
Shreddability= increase surface area, melts faster.
Meltability=higher fat, moisture content, higher meltability
Oiling off= high fat, lots of oils with heat
Blistering= aged cheese, large blister. unaged cheese, small blisters
Browning= excess sugars, amino acids, lactose = too much browning
Stretchability= higher level of calcium phosphate, tougher grainy texture. protein aging = softer texture
Storage for CHEESE
Dry: packaged dry, parmesan
Refrigeration: most cheeses, waxes reduce mold,
Frozen: based on water content. hard cheese:2 months
soft cheese:5months gouda, swiss
Poultry - Type of chicken
Chickens:
Broilers/fryers: M,F, slaughtered at 7 weeks, 3-5lbs
Roasters: M,F, slaughtered at 10-12 weeks, 6-8lbs,most common
Capons: M, slaughtered at less than 4months, castrated young=less testosterone=more fat more tender, 12-14lbs
Mature chickens: M,F, slaughtered at 10 months, after their breeding capacities, need slow cooking methods to tenderize.
