Involvement of μ/m-calpain in the proteolysis and meat quality changes during postmortem storage of chicken breast muscle.

The objective of this study was to investigate the role of calpain isotypes, especially poultry-specific μ/m-calpain in the proteolysis and meat quality changes of chicken breast muscle during postmortem storage. Calpain activity was detected by casein zymography, while the degradation of titin, desmin and Troponin-T was analyzed by sodium dodecyl sulfate - polyacrylamide gel electrophoresis and western blot. Meat quality indicators such as water holding capacity and tenderness were also studied. The correlation analysis between calpain activity, proteolysis and the changes in meat quality indicators indicated that there were strong correlations for μ-calpain during the first 12 h of storage, while such strong correlations for μ/m-calpain were only found in samples stored from 12 h to 7 days. Our study suggested that μ-calpain played a major role in meat quality changes while μ/m-calpain could also be involved but played a limited role in the proteolysis and meat quality changes during 12 h to 7 days postmortem storage of chicken breast muscle.