Meat PDST Home Economics Classification Carcass beef veal

Meat © PDST Home Economics

Classification Carcass = beef, veal, mutton, lamb, pork, ham, bacon. Poultry = chicken, turkey, duck, goose. Game = deer, rabbit, grouse, pheasant. Offal = liver, kidney, heart, tongue, tripe, sweetbread, brain.

Structure of Meat Muscle fibres, like hallow tubes, size depends on use the muscle gets, short fibres = tender meat. Fibres contain nutrients and extractives. Fibres held together with connective tissue (collagen) tough, becomes tender when cooked. Fat cells are spread between the fibres and cover the outside of the meat.

Tough v Tender Tough meat has long fibres and a lot of connective tissue, tender meat has short fibres and little connective tissue Causes: Activity, Age, hanging Tough meat is cheap and needs long slow cooking or some tenderising if fast cooking is to be used Tender meat is expensive and can be cooked quickly e. g. grilling, frying, roasting Ways to tenderise meat: beating, mincing, enzymes, marinating, long slow cooking e. g. stews and casseroles

Hanging After animal is killed muscles stiffen (rigor mortis) When meat is hung enzymes cause glycogen stored in liver and muscle cells changes to lactic acid The lactic acid tenderises the meat The lactic acid also helps preserve the meat giving it a longer shelf life

Nutritive Value Protein, 20 -25%, HBV, collegen, elastin, myosin, actin, globulin Fat, 10 -30%, saturated, chicken least, pork most Carbohydrate, 0%, needs to be served with food rich in carbohydrate

Nutritive Value Vitamins = B Group: B 1, B 2, Niacin, Folic Acid, B 6, B 12 - for nerves, blood and energy. Minerals = easily absorbed haem iron, phosphorus, calcium, sulphur. Water = 50 -70%

Dietetic Value Popular, expensive nutritious. Protein, for growth and repair, important for children, adolescents, pregnant women. The saturated fat content means meat should be reduced in diet of those with high cholesterol, heart disease. Obese people should choose chicken, turkey and lean meat to avoid fat. Good source of iron esp. for teenage girls and pregnant women. Good source of B vitamins especially B 12 for red blood cells.

Choosing Meat/ Storing Fresh Meat Choosing Clean hygienic shop. Same person shouldn’t handle money and meat. Pleasant smell, good colour, moist and firm. Raw and cooked meat separated. If prepacked check use by date and use quickly. Storing Remove plastic wrapping unless vacuum packed. Put on clean plate, cover loosely. Bottom shelf of fridge Use within 2 days, offal and mince use on day bought. Cured meat fat goes rancid store in wrapper and use inside a week once opened.

Effects of Heat or Cooking on Meat Protein denatures @ 4065°C, over cooking toughens it. Meat shrinks due to loss of juices and melted fat. Collagen changes to gelatine, meat tenderises. Red to brown because oxymyoglobin changes to haemochrome @ 65°C. Water soluble minerals & vitamin B dissolve into cooking liquid. Microbes destroyed.

Meat Processing Freezing: boned, trimmed, blast frozen – 30°C, fast frozen, sealed in moisture proof package, loss of extractive and soluble nutrients in drip, fat can go rancid if stored badly, freezer burn if exposed to air. Vacuum Packing: boned, wrapped in strong polythene, all air removed, often done with cured meat, needs refrigeration, has a use by date, once opened use quickly.

Meat Processing Curing: bacon and ham most common, cooled to 4°C, injected with brine, soaked in brine 4 days, hung in cold room 4/5 days, smoked or green, main change is to colour & flavour. Canning: e. g. corned beef, tongue, stew, similar to moist cooking, loss of B vitamins especially thiamine, meat tenderised and cooked. Dehydration: Packet meals, soup etc contain freeze dried meat. Once rehydrated use quickly, loss of Vitamin B and meat can become tough.

Meat Products Sausages: 1. fresh(25%fat), 2. cooked e. g. frankfurter, 3. dried e. g. salami (45%fat) Burgers Meat extractives: paste, cubes, powder used in gravy, stew, soup, as drink Pâtés: 65% fat, seasoned paste of meat, game, liver +wine/sherry Cold cooked meat e. g. corned beef Gelatine: soak in water to form gel, on heating gel becomes liquid = sol, on cooling sol becomes solid i. e. gelatinisation

Offal: Edible Internal Organs Lambs liver: protein, Vitamin A, D, B, Iron. Kidney: protein, iron, Vitamin B Heart: protein, Vitamin B Brain: Protein Sweetbread: protein Tongue: protein, calcium, Vitamin B Tripe: protein, calcium, Vitamin B Needs to be absolutely fresh and eaten on day of purchase Wash well in salted water and cook thoroughly

Poultry: Nutritive Value ü Protein: 20 -25%, HBV ü Carbohydrate: 0% ü Fat: white meat 1 -4%, Dark meat 7%, skin 14%, duck/goose 10%. ü Vitamin: B 1, B 2, Niacin less than red meat. ü Minerals: small amount calcium, less iron than red meat e. g. 0. 8 mg: 2 mg /100 g. ü Water: 50%-70%

Poultry: Choosing & Storing Choosing Fresh smell Pinkish-white colour, darker legs Flesh firm Available whole, jointed, coated, precooked, boned and rolled, poultry products = nuggets, burger, sausages, kievs rissoles Storing Remove wrapping, place on clean plate, cover loosely, bottom shelf of fridge. Defrost frozen poultry in fridge overnight because of danger of salmonella