Class #7: Meat and Poultry Flashcards
What is a steer?
Male, castrated when young to gain weight quickly
What is a bull?
Older, uncastrated and used for breeding
What is the difference between a heifer and a cow?
Heifers have not borne a calf.
How old are calves slaughtered for veal?
3 weeks-3 months old
What are veal fed?
Milk based diet, makes their flesh pale and milky
What is muscle tissue composed of?
H2O, adipose, muscle, CT, bone and ash
What are the 3 different kinds of protein in meat?
Myofibrillar (Actin and Myosin), Structural (CT),
Scarcoplasmic (Blood)
What is the structure of skeletal muscle?
Bundles of muscle fibres (Fibrils) surrounded by connective tissue.
Describe the mechanism of muscle contraction and relaxation.
- Each fibril is composed of sacromere units, which contain filament of actin(thin) and myosin(Thick). Together they form actomyosin.
- Actin and myosin slide across each other to form actomyosin cross links, which shortens the sacromere, making the muscle contract
- ATP is needed for muscle contraction
True or False: Connective tissue is made of proteins and mucopolysaccharides.
True
True or False: Collagen is made of Glycine, Hydroxyproline and proline.
True
What are the 3 main types of connective tissue proteins?
Collagen, Elastin, Reticulin
Where is elastin found?
Silver skin on meat (yellow and rubbery), does not soften with heating
Where is reticulin found?
Small fibres of connective tissue forming mesh around muscle cells that support tissues.
True or False: Older animals need more time to hydrolyze their connective tissues to gelatin.
True. Older =more CT
What kind of adipose tissue is responsible for marbling?
Intramuscular
What is the marbling window?
Near birth, adipocytes are multiplying, but before slaughter, adipocytes are increasing in size. Marbling window is between 100d-250d. Feed cattle richer grain during this time to increase marbling.
True or False: Younger animals have yellower fat.
False. Older animals have yellower fat, younger animals have whiter fat due to carotenoids in the feed.
True or False: The type of fats the animals are fed relate to the types of fat found in their meat.
True
Where is yellow bone marrow found?
Long bones.
Why is red marrow red?
Supplied by many blood vessels, spongy centre in bones.
Where does meat primarily get its colour from?
Myoglobin, hemoglobin to a much smaller degree.
True or False: Myoglobin increases with age, therefore making the meat darker.
True
True or false: More exercised muscle needs more oxygen, giving it more myoglobin.
True
True or false: Myoglobin recieves O2 from the blood and stores it in muscles.
True
True or false. Myoglobin changes colour due to age.
False. Myoglobin contains Fe in the centre, and it’s oxidation/reduction changes the colour of myoglobin.
True or False: Reducing myoglobin give it a bright red colour.
False. Oxidizing Myoglobin forms oxymyoglobin, making it bright red.
True or False: Myoglobin in meat is purple/red.
True
What is nitrite used for in the food industry?
To maintain bright pink/red colour of meat. Myoglobin+nitrite=nitrosyl hemochrome (converts to nitric oxide to cure meat)
It also stops bacterial growth and slows rancidity.
True or false: Processed red meat is a group 1 carcinogen.
True.
Describe the proposed cancer causing mechanism of hemoglobin.
-Heme is broken down in the gut to form N-nitroso compounds
-Damages intestinal cell lining
-To heal, DNA replication is initiated
=more chances of errors, mutations
Which carcinogen is produced when meat is cooked at too high a temperature?
AA’s and creatine in meat produce acrylamide.
Why does marbled meat sell for more?
Intramuscular fat is deposited at a specific time in growth, gives better mouthfeel, moist.
What changes in the body occur with rigor mortis?
6-24h after death, body becomes stiff, oxygen in depleted, and muscles lock (toughen). Reverses in 1-2 days, meat must be hung to stretch out the muscles and relax them.
Describe aging meat.
Ripening the carcass in fridge to reverse rigor mortis. Enzymes active in the meat break down fibres to give more tender meat.
Why does pounding meat make it tender?
It cuts up the connective tissue.
True or False: Electrical stimulation of meat makes it tougher.
False. Electrical stimulation accelerates the enzymes present in meat.
How far do commercial enzyme penetrate in meat?
0.5-2mm
How do salts tenderize meat?
Retain moisture, break down CT
How much meat is sold as processed meat?
1/3
Describe curing meat.
Salts/Nitrites are added to meat, H2O pools where it’s injected to retain moisture in the long term, draws out H2O in the short term.
What temperature should you not exceed when cooking meat with dry heat?
60C, after that the CT dissolves into gelatin and becomes brown and shrunken.
True or False: You should use less tender cuts with dry heat.
False. Other way around.
How should you cut meat to ensure tenderness?
Across the grain to cut muscle fibres.
True or False: Insects are complete proteins.
True
What is a broiler/fryer? (Chicken)
M or F, slaughtered at 7 weeks (3-5 lbs)
What is a cornish game hen?
Cornish hen crossed with another chicken breed.
What is a roaster? (Chicken)
M or F, slaugtered at 10-12 weeks (6-8lbs)
What is a capon?
M, neutered and sold under 4 mo (12-14lbs)
What is a hen/tom?
Turkey, around 15 mo old (hen is 14lbs, tom is 26lbs)
What does free range mean?
The birds have access to the outdoors for some portion of the day.
What does free run mean?
Open concept barn, but all chickens raised for meat. May still be overcrowding, birds do not necessarily have access to the outdoors.
What is in ash?
Vitamins and minerals.
What is the difference between white and dark meat?
White meat has less myoglobin, dark meat is exercised more (thigh/drumstick).
Describe the processing of a ready to cook chicken.
No blood, feathers, head, feet, and it has been evicerated (Entrails removed), fat has been removed from organs and it sometimes sold with the bird.
True or False: Convenience chicken has been taken apart.
True.
What is the rule of thumb when buying chicken (amount wise)?
Buy 1/2 lb more per serving, because ready to cook poultry contains lots of inedible bone and fat.
Why shouldn’t you wash raw chicken?
Cross contamination from splashing water.
What is the gold standard for determining doneness?
Thermometer to internal temp of 165F(74C) for 15 seconds.
True or False: Braising uses small pieces of chicken.
False: Uses large chunks
True or False: When braising, you should cook the garnish separately.
True
True or false: Braising should be used for older birds.
True
True or False: Braising is done on the gas range.
False, done in oven.
When Fe in myoglobin is in the 3+ form, which pigment is present?
Metmyoglobin. (brown)
True or False: Salmonella can be asymptomatic.
True
