Post-mortemproteolysis and tenderisation are more rapid and extensive in female duck breast muscle

Postmortem role of calpain in Chinese and Wuzong goose muscles

The purpose of this study was to compare postmortem proteolysis and tenderization between Chinese and Wuzong goose breast muscles. Four months old Chinese (CG, n = 15) and Wuzong (WZ, n = 15) goose carcasses were vacuum-packaged 10 to 15 min postmortem and stored at 5°C. Breast (Pectoralis major) samples from each carcass were sampled at 0 (∼10 min postmortem), 1, 3, and 7 D of storage. Our results showed that the decrease in pH and calpain-1 activity was not different in CG and WG samples. However, the decrease in calpain-11 activity, desmin content, and shear force were more rapid (P < 0.05) in WZ than in CG samples. Our results indicate that postmortem proteolysis and tenderization of goose breast muscle were more extensive in WZ than in CG goose muscle.

The Effect of µ/m-Calpain on Protein Degradation of Chicken Breast Meat

This study was designed to determine the effects of µ/m-calpain on the degradation of cytoskeletal proteins in pectoralis major. Four chickens were slaughtered and the breasts were removed and stored for 12 hr at 4 °C. Each sample was divided into three groups and respectively immersed in control reagent, calpain inhibitor, and caspase inhibitor at 4 °C. The samples were used to evaluate troponin-T and desmin degradation, calpain activity, and myofibril ultrastructure at 12 hr, day 1, day 3, and day 7. Casein zymography revealed that µ-calpain could not be detected in all samples after 12 hr postmortem. The calpain inhibitor inhibited µ/m-calpain activity and reduced troponin-T and desmin degradation during 7 day postmortem. The caspase inhibitor inhibited µ/m-calpain activity and, troponin-T and desmin degradation before day 3 postmortem. The findings suggest that, µ/m-calpain had an effect on cytoskeletal protein degradation after 12 hr postmortem.

Differential protein profiles in duck meat during the early postmortem storage period

The present study was designed to investigate proteomic differences in duck breast muscle during the early postmortem storage period. The meat quality was evaluated at 0 hr and 24 hr postmortem at 4°C in Pekin ducks, black Muscovy ducks and Mule ducks. Differentially expressed proteins were detected by two-dimensional gel electrophoresis (2-DE) and matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF/TOF MS) at 0 hr and 24 hr postmortem in the three duck breeds. The results showed that 53 proteins spots were differentially expressed at 0 hr and 24 hr postmortem at 4°C in Pekin ducks, 75 spots in black Muscovy ducks, and 72 spots in Mule ducks. A total of 30 (10 spots for each breed) were selected for identification by mass spectrometry. Seven proteins were identified in Pekin ducks, eight in black Muscovy ducks and seven in Mule ducks. Moreover, the above results obtained by 2-DE and MALDI-TOF/TOF MS were confirmed by western blotting. To our knowledge, this study is the first to provide insights into the protein profiles of ducks during postmortem storage and provides a better understanding of the biochemical processes that contribute to duck meat quality.