Comparison of postmortem Proteolysis between breast and leg muscles in Chiayi native chickens

Abstract

Postmortem Proteolysis of breast (BM) and leg (LM) muscles in Chiayi native chickens at 5°C were compared. Myofibrils were purified from BM and LM samples that were randomly taken from carcasses after 0, 1, 3, 7 and 14 days of storage al 5°C. Fragmentation of myofibrils were determined, and degradation of myofibrillar proteins were analyzed by the SDS-PAGE and western blots. The results showed that myofibril fragmentation index (MFI) was significantly (p<0.05) higher in BM than in LM samples. Disappearance of titin and nebulin and appearance of the 30 kDa component were more rapidly as seen on SDS-PAGE in BM than in LM samples. Western blots labeled with a monoclonal antibody to desmin also demonstrated that desmin degraded more quickly in BM samples. Our data suggested that postmortem proteolysis occurred more rapidly in breast muscles in Chiayi native chickens.