EFFECTS OF ENDOGENOUS PROTEASES EFFECTORS ON THE DEGRADATION OF TROPONIN-T AND DESMIN OF CHICKEN BRISKET MUSCLE DURING POSTMORTEM AGING1

摘要

IntroductionA number of investigations have indicated that consumers considered tenderness as the most important eating quality characteristics of meat. In practice, storage of meat, especially, beef, lamb and pork for a given time is a prerequisite for the development of tenderness. To date, it has been extensively studied and well established that postmortem degradation of myofibrillar proteins has close relationship with the structural destruction and improved tenderness of meat during refrigerated storage. However, currently, the mechanism underlying postmortem myofibrillar protein degradation is still an unresolved question. Ji et al. (2006) reported that meat postmortem tenderization and myofibrillar protein degradation was caused by the elevated concentration of free calcium in muscle fiber sarcoplasm. While, others believed that meat tenderizing process is mainly enzymatic in nature (Ouali et al., 2006). The most studied proteolytic systems include calpains, cathepsins and proteasome, among which the role of calpains especially, -calpain are highlighted in meat aging, whereas, this statement has never been definitely proven and far from being fully understood. Hence, it is justifiable that, in addition to the proteases cited above, other proteases should not be excluded and are possibly involved in meat postmortem aging.