Meat Types and Composition

Meat Types

• Beef comes from cattle.
  • Steers are castrated males.
  • Bulls are uncastrated males.
  • Heifers are females that have not borne a calf.
  • Cows are females that have borne calves and are less desirable.
  • Calves 3 to 8 months old are too old for veal and too young for beef.
  • Baby beef is meat from calves 8-12 months old.
  • Veal is meat from calves between 3 weeks and 3 months old, known for its milky flavor, pale color, and tenderness.
• Lamb and mutton are meat from sheep.
  • Lamb is from sheep under 14 months old.
  • Mutton is from sheep over 14 months old.

Meat Composition

• Meat is composed of water, muscle, connective tissue, adipose tissue, and bone.
• Muscle tissue is the main source of protein in animals.
  • Muscle fibers are made of myofibrils which affect meat texture.
  • Small myofibrils result in finer muscle bundles and soft consistency.
  • Myofibrils are separated into sarcomeres.
  • Actin and myosin are proteins in sarcomeres that slide past each other during muscle contraction, forming actinomyosin.
• Connective tissue holds the muscle cells together.
  • Collagen is the most abundant protein in connective tissue.
  • Collagen toughens meat but softens when exposed to moist heat.
  • Elastin and reticulin are the other two connective tissue proteins.
  • Muscles with more connective tissue, like those in the neck, shoulders, legs, and flank, are tougher.
  • Loin and rib muscles are more tender due to less exercise.
  • Older animals have more collagen, making their meat tougher.
  • Tougher cuts require slow, moist cooking to soften the collagen.
• Adipose (fatty) tissue is fat.
  • Cover fat is on the outside of meat.
  • Intramuscular fat or marbling is found within the muscle.
  • Fat content varies based on breed, age, diet, and exercise.
  • Well-marbled beef is more expensive.
  • Fat color turns yellow with age due to carotenoid pigments in the feed.

Meat Color

• Meat color comes from myoglobin and hemoglobin.
• Myoglobin changes color with oxygen exposure, turning bright red and then brownish-red.
• Cooking meat initially turns it bright red, then denatures it to grayish brown.
• Stored cooked meat can turn yellow, green, or faded.
• Nitrites are added to processed meats to prevent discoloration.
• Extractives, including creatine, creatinine, urea, and uric acid, contribute to meat flavor.

Purchasing Meat

• Government laws require meat inspection for safety.
• Yield grades and quality grades are voluntary and help consumers choose meat.
• Organic meat is from cattle raised exclusively on milk, grasses, and grains.
• Yield grade measures the amount of lean meat on the carcass.

Meat Tenderness

• Tenderness is influenced by cut, age, fat content, and treatment.
• Tender meats benefit from dry heat cooking (roasting, broiling, grilling, pan-broiling, frying).
• Tougher cuts are suitable for moist heat cooking (braising, simmering, stewing, steaming).
• Natural tenderizing factors include:
  • Cut of meat
  • Age (lower collagen content in younger animals)
  • Marbling (intramuscular fat)
  • Slaughter conditions
  • Aging
• Rigor mortis is the temporary stiffening after death.
• Aging is the ripening process that involves hanging carcasses in refrigerated environments.

Postmortem Muscle Changes

• Pre-rigor mortis:
  • ATP decreases
  • Lactic acid buildup in cells
  • pH decreases
  • Glycogen decreases
  • Muscle becomes more extensible
  • Rigor mortis sets in
• Rigor mortis: Muscle stiffens and becomes less tender.
• Post-rigor stage: Muscle relaxes and becomes more tender.
• Meat pH: After slaughter, the pH gradually decreases due to lactic acid accumulation.

Minimizing Muscle Shortening

• Hanging carcasses after slaughter stretches muscles, reducing actomyosin cross-linking.
• Pre-rigor temperature control minimizes fiber shortening, optimal temperature is 15–20 C (59-68 F).
  • Higher temperatures increase shortening.
  • Lower temperatures cause "cold shortening" due to calcium ions remaining in the sarcoplasm.

Meat Preparation

• Meat should be cleaned with paper towels and trimmed of fat before cooking.
• Doneness is determined by time/weight charts, color changes, internal temperature, and touch.
• Processed methods like curing, smoking, canning, and drying were used before refrigeration.

Changes During Heating

• Proper cooking time and temperature maximize tenderness, juiciness, and flavor.
• High temperatures for extended periods toughen, shrink, and harden meat.
• Carry-over cooking continues cooking after removal from heat, distributing heat more evenly.
• Doneness can be determined by various methods.
• Touch as a test for doneness: Pressing lightly on the center of the lean tissue can help determine if meat is rare, medium, or well done.

This quiz covers the various types of meat including beef, lamb, and mutton, along with their classifications based on age and gender. Additionally, it examines the composition of meat, focusing on muscle tissue and its characteristics. Test your knowledge on the fundamentals of meat types and their composition.