Postmortem Degradation of Calpain and Myofibrillar Proteins in KHAPS Black Pig Skeletal Muscles

• Main Authors: Ya-Shiou, Chang, 張雅琇
• Other Authors: Rong-Ghi R. Chou
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/96639764307592849863

碩士 === 國立嘉義大學 === 動物科學系研究所 === 98 === The objective of this study was to compare the postmortem changes in Psoas major (PM) and Longissimus dorsi (LD) muscles from KHAPS Black Pigs (50 % Meishan and 50 % Duroc). Psoas major and Longissimus dorsi of gilts were removed from the carcasses, vacuum-packed and stored at 5°C. Muscle samples were randomly taken after 0.5, 1, 2, 3, 7 and 14 days of storage. The at-death samples were taken within 3-h postmortem. The results showed that postmortem pH were significant lower (P<0.05) in LD than in PM samples. Western blot indicated that desmin degradation, 30 kDa degradation component accumulation and µ-calpain autolysis were more rapidly in LD than in PM samples (P<0.05). Casein zymography also showed that µ-calpain autolysis was faster in LD than in PM samples (P<0.05). Our results suggest that postmortem changes in calpain and myofibrillar proteins may be affected by different part of porcine skeletal muscle. Pearson correlation coefficients indicated that µ-calpain activity was positively correlated with amount of µ-calpain 80 kDa subunit in both LD and PM samples. µ-calpain activity was correlated positively with desmin amount and negatively with the amount of the 30 kDa degradation component in LD samples, instead of PM samples. Our results suggest that µ-calpain might play a dominant role in dictating postmortem proteolysis in LD muiscle and an essential role in PM muscle.