Meats Flashcards
What is the definition of meat? Why does it exclude poultry and fish?
- muscles of mammals; can include organs and glands
- Because “non-mammals”
How are beef classified?
By age and sex
Name the 4 types of beef.
1) Steers (M) (castrated young to gain weight quickly)
2) Bulls (M) (uncastrated, processed meats and pet foods)
3) Heifers (F) (no born calves) and Cows (F) (birth to less than one calf, less desirable)
4) Calves (F) (M) 3-8, baby beef (8-12 months)
What are veals? What is their diet?
- Young calves M, F
- 3 weeks to 3 months
- Restricted movement
- Milk-based diet or formula
How is the meat of veals?
- Milky flavour
- Pale colour
- Tender (slightly less if free-range)
Name the 2 types of sheep.
1) Lamb (< 14 months)
2) Mutton (> 14 months)
How is the meat of mutton?
- Darker, tougher meat
* Stronger flavour
Name the 3 types of pork.
1) Swine (F) (M) - slaughtered at 7-12 months
2) Pigs (<4 months)
3) Hogs (> 4 months)
What is the composition of meat?
- H2O (75%)
- Muscle
- Connective tissue
- Adipose tissue (fat)
- Bone
What is the primary source of dietary meat?
Skeletal muscle
Name 3 characteristics of skeletal muscle. What do they impact?
- Connective tissue
- Muscle fibers (cells)
- Fibrils
- -> impacts cut of meat (tender or tough)
What are muscle fibril composed of?
2 sarcomere units
What does each sarcomere contain? How are the sarcomeres shortened? What is consumed?
- 2 protein filaments:
- Actin (thin) + Myosin (thick) –> Actomyosin
• Filaments slide across each other forming actomyosin(cross-links), which shortens the sarcomere
• ATP consumed
Where is connective tissue found?
ligaments and tendons
What is the composition of connective tissue?
proteins + mucopolysaccharides
What are the 3 functions of connective tissue?
- Surrounds all living cells
- Provides structure and adhesiveness
- “Glue” that holds muscle fibers together
What are the two connective tissue proteins?
Elastin and reticulin
What forms connective tissue proteins?
Collagen
What is the most abundant protein in connective tissue?
Collagen
What does animal maturity lead to in terms of collagen?
↑ collagen content
↑ covalent cross-links between collagen strands
How does the cut affect collagen? (2)
• Cuts high in connective tissue: ↑ collagen
• Avoid cuts in muscles for movement
-> Neck, shoulders, legs, flank
What is elastin?
- Yellow and rubbery (silver skin)
- Elastic qualities duh!
- Small amounts in meats (except cuts from neck and shoulder)
What is reticulin?
- Fine mesh network
* Supports tissues (e.g. bone marrow, liver, and lymphatic system)
Why does elastin have to be removed?
because does not soften with heating
What is subcutaneous fat?
- Fat under skin
- Insulation
- Padding in abdominal cavity for sensitive organs
What is intramuscular fat?
- Fat within muscle fibers
- Creates marbling
- Seen as little, white streaks or drops
How does the animal’s age affect fat?
Colour
Young animals (white) –> Older animals (yellow)
How does the animal’s diet affect fat?
Type
High PUFA diet in swine -> Pork is also high in PUFA
How does the animal species affect fat?
Softness
Lamb (hard, brittle, dense) vs. Beef (soft)
What are landmarks to identify various meat cuts from carcass?
Bone
What is bone marrow?
Soft, fatty material in center of large bones
What colour is bone marrow in long bones? In spongy center of other bones?
1) Yellow – in long bones
2) Red – in spongy center of other bones
What gives meat its colour?
Myoglobin and Hemoglobin
-> proteins found in meat that give meat its pigment
Differentiate myoglobin and hemoglobin.
Myoglobin: Receives O2 from blood and stores it in muscles
Hemoglobin: Transports O2 throughout body
Name the 3 factors that increase myoglobin (darker red).
1) Increased exercise (higher O2 demand, more myoglobin)
2) Increased animal age (increased myoglobin, beef more than veal, mutton more than lamb)
3) Species (red meats - beef and lamb carry more red than pork)
What is the structure of hemoglobin?
4 protein polymer strands and 4 heme molecules
What are the 3 stages of myoglobin following slaughter? What does it depend on?
1) Slaughter - myoglobin - purplish-red (O2 depleted)
2) Meat Cut from carcass - oxymyoglobin - bright red (indicator of freshness)
3) Storage - metmyoglobin - brownish red (bacteria, O2, light)
- > depends on the oxidation and reduction of the iron
What happens to myoglobin when it is heated?
1) Cooking
2) Well-done meat
3) Storage
- Denatures myoglobin
Cooking, bright red
Well-done meat, grey
Storage (too long), yellow, green, faded
What does the food industry add to meat to keep from browning? What colour does it give
Nitrite, gives it its pink colour