Water - 2 thirds of lean meat is water.
Protein - Main protein is Myosin. All proteins are of High Biological Value (H.B.V.)
Mineral Elements - Most important is Iron.
Vitamins - Important source of B group vitamins - B1, B2 and B12.
Fat - Varies according to age and type of animal and the cut of meat.
Carbohydrates - Not present except in Liver.
Conversion of muscle into meat
Depends greatly on many pre-slaughter factors.
1) Loss of weight / disease in abattoir causes lack of moisture.
2) Several hours after death the carcass stiffens in RIGOR MORTIS. Tough and dark if cooked.
3) Final pH is important - 5.6 is ideal - if higher means poor quality.
4) Post slaughter. Once RIGOR MORTIS disappears, meat becomes softer and juicier.
Structure of muscle tissue in meat
Muscle fibre is made from MYOFIBRILS surrounded by fluid.
The SARCOLLEMA is a sheath that surrounds the fibre which is in parallel across cells - STRIATED MUSCLES.
The CONNECTIVE TISSUE holds the muscle bundles together.
Cuts of meat
Lamb: Leg, Shoulder, Loin, Chump, Breast, Best end of neck, Scrag and Middle.
Pork: Leg, Chump, Loin, Belly, Neck End, Hand and Spring.
Beef: Neck, Clod, Shin, Chuck and blade, Thick rib, Brisket, Fore rib, Thin rib, Sirloin, Fillet, Thin flank, Rump, Topside and silverside, Thick flank and Leg.
Storage and Handling
Stored at chill temperatures (5C or less) to slow down enzyme changes after conditioning and minimise microbial growth.
The addition of 10% carbon dioxide to a chill store will extend storage life but may cause some darkening of the meat.
If kept for too long at room temperature, meat becomes 'soggy'.
This is partly due to the breakdown of its protein by enzymes.
Putrefaction eventually sets in with production of slime and foul odours caused by Pseudomonas bacilli,