what are the importance of rigor mortis in meat processing
tenderness of meat
title: Rigor mortis text: fibers. Rigor mortis then spreads to the other muscles, including the internal organs, within the next four to six hours. The onset of rigor mortis is affected by the individual's age, sex, physical condition, and muscular build. Rigor mortis may not be perceivable in many infant and child corpses due to their smaller muscle mass. Rigor mortis is very important in meat technology. The onset of rigor mortis and its resolution partially determine the tenderness of meat. If the post-slaughter meat is immediately chilled to 15 °C (59 °F), a phenomenon known as cold shortening occurs, whereby the muscle sarcomeres title: Meat text: kg, is believed to increase the water-holding capacity and tenderness of the flesh when cooked. "Rigor mortis" sets in a few hours after death as ATP is used up, causing actin and myosin to combine into rigid actomyosin and lowering the meat's water-holding capacity, causing it to lose water ("weep"). In muscles that enter "rigor" in a contracted position, actin and myosin filaments overlap and cross-bond, resulting in meat that is tough on cooking – hence again the need to prevent pre-slaughter stress in the animal. Over time, the muscle proteins denature in varying degree, with the exception of the title: Rigor mortis text: shrink to a third of their original length. Cold shortening is caused by the release of stored calcium ions from the sarcoplasmic reticulum of muscle fibers, in response to the cold stimulus. The calcium ions trigger powerful muscle contraction aided by ATP molecules. To prevent cold shortening, a process known as electrical stimulation is carried out, especially in beef carcasses, immediately after slaughter and skinning. In this process, the carcass is stimulated with alternating current, causing it to contract and relax, which depletes the ATP reserve from the carcass and prevents cold shortening. The degree of rigor mortis may be title: Rigor mortis text: Rigor mortis Rigor mortis (Latin: "rigor" "stiffness", "mortis" "of death") or postmortem rigidity, the third stage of death, is one of the recognizable signs of death, caused by chemical changes in the muscles post mortem, which cause the limbs of the corpse to stiffen. In humans, rigor mortis can occur as soon as 4 hours post mortem. After death, respiration in an organism ceases, depleting the source of oxygen used in the making of adenosine triphosphate (ATP). ATP is required to cause separation of the actin-myosin cross-bridges during relaxation of muscle. When oxygen is no longer present, the body may title: Meat text: collagen and elastin of connective tissue, and "rigor mortis" resolves. Because of these changes, the meat is tender and pliable when cooked just after death or after the resolution of "rigor", but tough when cooked during "rigor." As the muscle pigment myoglobin denatures, its iron oxidates, which may cause a brown discoloration near the surface of the meat. Ongoing proteolysis also contributes to conditioning. Hypoxanthine, a breakdown product of ATP, contributes to the meat's flavor and odor, as do other products of the decomposition of muscle fat and protein. When meat is industrially processed in preparation of consumption, it may