Final Flashcards
What is the composition of meat?
- Water: 75%
- Protein: 15-20%
- Fat: 5-40%
- Carbohydrates: 0%
- Excellent source of phosphorous, niacin/riboflavin
- Good source of thiamin, iron
What are the type of proteins in meat?
- Myofibrillar (myosil; thick filaments, actin; thin filaments)
- Function: contractile
- Found in muscle/flesh of meat (sarcoplasm of fibres) - Sarcoplasmic/Chromoproteins (myoglobin; flesh, hemoglobin; blood)
- Function: transport oxygen - Mitochondrial (enzymes)
- Function: chemical reactions - Connection (collagen, elastic)
- Functions: structural, holding muscle to bone
- Found in connective tissue
What happens when you add heat to the meat proteins?
- Heating causes denaturation of myofibrillar proteins
- Overheating = overcoagulation = tough meat
- Proteins shrink due to excessive H bonds, squeeze out water = dry meat
- Collagen can be hydrolyzed into gelatin by various cooking methods
- Elastin is not affected by normal cooking procedures
What are the factors of tenderness in meat?
- Length of aging
- Rigor mortis = after slaughter, muscles are in contracted state = tough
- If held under specific period of time under 1-2 C, muscles will loosen
- Proteolytic enzymes in meat break bonds holding muscles in contracted state
- If meat is hung during aging, gravity stretches muscles
- Tenderness increases as aging time increases - Age of animal
- Amount of connective tissue increases with age of animal
- Meat from young pork/lamb animals is more tender - Species of meat
- Beef, pork, and chicken vary in amount of connective tissue/muscle - Specific muscle in animal
- Exercise makes muscle fibres expand = more connective tissue = larger diameter of muscle fibres = more tough
- Most tender cut is the tenderloin - Method of cooking
- Moist heat cooking methods increase tenderness
What is marbling and what does it do?
- Fine white streaks of fat in lean parts of a cut of meat
- Trace, slight, small, or modest
- Enhances flavour and juiciness = greater perception of tenderness
What are the beef grades?
- Canada Prime: slightly abundant marbling or higher
- Canada AAA: small marbling or higher
- Canada AA: slight marbling but less than small
- Canada A: trace marbling but less than small
What are the tender cuts of meat?
Along vertebrate
- Rib steak/roast
- Rib wholesale cut
- Rib bone - Wing steak
- Loin wholesale cut
- Rib bone - Sirloin steak/roast
- Sirloin wholesale cut
- Wedge or hip - T-bone
- Loin wholesale cut
- ½ vertebra (small tenderloin piece) - Porterhouse
- Loin wholesale cut
- ½ vertebra (bigger tenderloin piece)
What are dry heat cooking methods?
- High temperature (> or = 160 C), short period of time, no water
Methods vary depending on cut:
- Broiling, frying, pan-broiling, BBQ, deep fat frying = thin cuts (sirloin steak, rib steak)
- Baking, roasting = thicker cuts (rib roast, sirloin roast)
What are dry heat cooking methods used for?
Used for tender cuts of meat
- Beef: less exercised areas (rib, loin, sirloin wholesale cuts) = less connective tissue = smaller diameter of muscle fibres
- Pork and lamb: young animals = less connective tissue = small diameter muscle fibres
- Chicken and fish: little connective tissue, small and short muscle fibres = dry heat methods preserve distinctive flavour
Discuss overcooking in dry heat methods.
- Overcooking occurs more readily with dry heat methods
- Too high a temperature or too long cooking time
- Very easy to overcook tender meats
- Overcooked fish is dry, tough, and have very high concentration of fish flavour
- Note: coating in flour also provides physical barrier against overcoagulation
Is cooking in the microwave a dry heat method?
- Cooking in microwave is not a dry heat method because water in meat turns into steam
- Stoves have vent to allow steam to evaporate, microwave does not = moist environment
What are the less tender cuts?
- Blade steak/roast
- Chuck wholesale cut
- Shoulder blade or rib - Round steak/roast
- Hip wholesale cut
- Leg bone - Brisket
- Brisket wholesale cut
- Boneless - Stewing beef
- Shank wholesale cut
- Boneless - Ground beef
- Chuck (neck) wholesale cut
- Boneless
What are moist heat cooking methods?
- Low temperatures (< or = 100 C), longer cooking times, use of water
- Allow hydrolysis of collagen connective tissue protein into gelatin (more tender) = increased tenderness
Methods vary depending on cut:
- Braising of ribs, steaks, chops = thin cuts (blade steak, round steak)
- Pot roasting = larger cuts
- Stewing = small pieces of meat
- Pressure cooking
What are moist heating cooking methods used for?
- Used for less tender cuts of beef (chuck, shank, brisket, plate, hip, flank wholesale cuts) which received more exercise
- Veal is from very young male (bull) calves that have high proportion of connective tissue to muscle/flesh because of less time for muscle development = less tender
- Grain fed weighs more than milk fed
What are ways to tenderize less tender cuts of meat other than moist cooking?
- Acid (beer, wine, lemon juice, tomato juice)
- Added to raw meat
- Marinating meat: place raw meat in seasoned liquid (marinade) which contains acid to add flavour and tenderize meat
- Increases water holding capacity of actin and myosin = increase in juiciness
- Cooking that meat in acid hydrolyzes collagen connective tissue into gelatin = increase in tenderness
- If you add acid to partially cooked meat, acid hydrolyzes collagen into gelatin = increase in tenderness but not juiciness - Mechanical action (chopping, grinding, pounding)
- Breaks up large diameter muscle fibres and connective tissue
- Increases surface area, allowing for areas for heat/moisture to hydrolyze collagen into gelatin - Proteolytic enzymes (papain from papayas, ficin from figs, bromelain from pineapple)
- Hydrolyzes peptide bonds between amino acids (breaking linkage) in muscle fibres
- Affects collagen and elastin both
- Amount of enzyme and length of time must be controlled
- Otherwise meat becomes mushy in texture due to myosin and actin being completely hydrolyzed
What is Maillard browning?
- Nonenzymatic browning reaction on the surface of meat or baked products
- If you coat the meat in flour, it is dextrin browning reaction
- Occurs in high heat, low moisture conditions (dry heat cooking methods)
- Reaction occurs between amino acids (protein) + reducing sugar + dry heat conditions = melanoids (brown coloured pigments)
- Reducing sugar is glucose in meat or fructose, lactose or galactose in baked products
- NOT sucrose (white sugar) as it can be further broken down
Discuss meat colour.
Chromoproteins: myoglobin (80-90% of meat colour), hemoglobin (10-20% of meat colour)
- Myoglobin is the colour of raw meat = purplish colour
- Globin: protein
- Heme: nonprotein, ring structure, conjugated double bonds, never changes
- Central Fe atom: found in heme, exists in reduced (2+) or oxidized (3+) state
- Water: replaced by oxygen or nitric acid - Oxygenation: addition of 2 O2 atoms to myoglobin to form oxymyoglobin
- Water molecule is replaced with oxygen
- Colour changes from purple-red to bright-red - When oxygen is depleted, myoglobin forms metmyoglobin instead (brown-ish ed)
- Occurs when meat is covered in wrap that is not permeable to oxygen, coating meat in flour/marinade, or stacking meat - When reducing substances (chemicals in meat) are depleted, iron atom is oxidized
- Occurs when meat is stored in higher temperatures or when microorganisms grow and multiply (odour, slime)
- Colour changes to grey-brown - When you cook meat, you denature the globin protein and central iron atom moves to oxidized state from the heat
- Denatured globin hemichrome forms
- Internal colour of meat is brown or grey-brown
Discuss Salmon colour.
- Salmon contains a pigment called astaxanthin (carotenoid)
- Very stable during cooking (becomes more opaque, slight fading)
- Dry-heat methods are used to allow Maillard browning to occur
What is cured meat? What is in the mixture?
- Occurs to pork, beef, chicken (bacon, ham, corned beef, pastrami, sausages)
- Often vacuum packaged = anaerobic conditions = preserve
Involves applying a curing mixture to fresh meat in the form of liquid or dry rub/mixture
- Salt
- Sodium nitrite
- Produces nitric oxide, converted to nitrosamines (carcinogenic) during cooking at high temperatures
- Limit consumption, cook at moderate temperatures - Seasoning/flavouring
Discuss cured meat colour.
- Covering raw meat with curing mixture excludes oxygen = myoglobin/oxymyoglobin converted to metmyoglobin
- Water molecule attached to metmyoglobin is replaced by nitric oxide produced by sodium nitrite = nitric oxide myoglobin forms = red/pink colour
- When cured meat is cooked, nitrosyl hemochrome is formed = intense pink in the interior
- Globin portion is denatured but nitric oxide is still attached
What are the cooking losses in meat?
- Evaporation of water
- Occurs more with dry heat methods (>100 C)
- Lower in rare than well-done meat - Drip loss (fat, fat-soluble vitamins, pigments, protein)
- Higher with moist heat
- Retained in sauce/gravy - Nutrients
- Higher with larger surface area
- Greater loss of B-vitamins (especially thiamin)
- More common in dry heat cooking methods due to increase in temperature
What is the composition of baked products?
- Endosperm
- Starch granules
- 70-75% protein
- 20% B-vitamins - Aleurone cells
- Most of the protein and B-vitamins are found here (combination of endosperm and bran) - Bran
- 20% protein
- >60% B-vitamins
- Fibre (hemicellulose, cellulose) - Scutellum
- Germ
- 8% protein
- 30% of B-vitamins
- Saturated fats
What are the types of flour? Discuss milling.
Milling: conversion of wheat grain into white flours by separating bran and germ from endosperm and reducing size of endosperm into flour size particles.
- White flours
- Only endosperm
- All purpose flour: 10.5% protein
- Cake & pastry flour: 9.7% protein
- Bread flour: 11.8% protein - Whole wheat flours
- Bran, germ, and endosperm
- 13% protein
What is gluten and what does it do? How does it form?
- Complex protein created from proteins gliadin (plasticity) and glutenin (elasticity) found in wheat, rye, and oat flours
- Hydration (water added) and manipulation (mixing, kneading)
Gives visco-elastic properties to batters and dough:
- Allows them to hold small air cells
- Allows a dough to be kneaded and rolled
- Allows batters and doughs to expand