MEAT CONTRACTION AND RELAXATION: A REVIEW OF EFFECT ON MEAT TENDERNESS

Résumé

The demand for high-quality meat has increased. Flavor, juiciness, and tenderness are the three main attributes that influence the sensory enjoyment of meat. Tenderness has been shown to have the largest role in consumer purchasing decisions. The tenderness of a piece of meat is a result of several factors which can be considered sequentially. After an animal is slaughtered, blood circulation enough energy to contract the muscles, and also produces lactic acid. With no blood flow to carry the lactic acid away, the acid builds up in the muscle tissue. If the acid content is too high, the meat loses its water-binding ability and becomes pale and watery. If the acid is too low, the meat will be tough and dry. The lactic acid buildup also releases calcium, which causes muscle contraction. As glycogen supplies are depleted, ATP regeneration stops, and the actin and myosin remain locked in a permanent contraction called rigor mortis. Freezing the carcass too soon after death keeps the proteins all bunched stops, and muscles exhaust their oxygen supply. Muscle can no longer use oxygen to generate ATP (adenosine triphosphate) and turn to anaerobic glycolysis, a process that breaks down sugar without oxygen, to generate ATP from glycogen, sugar stored in muscle. The breakdown of glycogen produces together, resulting in very tough meat. Aging allows enzymes in the muscle cells to break down the overlapping proteins, which makes the meat tender. Without ATP, actin and myosin remain locked in a permanent contraction called rigor mortis