Involvement of apoptosis in meat quality attributes using the callipyge lamb model: 2. heat shock protein 27 and meat toughness

The objective of this study was to determine an involvement of heat shock protein (HSPs) in tenderness development of loins from callipyge lambs. Loin samples (M. longissimus thoracis) from sixteen lambs across four genotypes were collected throughout postmortem aging. More intact HSP27 in callipyge was coincided with higher levels of intact desmin and troponin T, less calpain-1 autolysis, and higher shears force values compared to other non-callipyge phenotype lambs (P<0.05). Positive correlations of anti-apoptotic activities (shown by elevated HSP27 and procaspase 3, and less cytochrome c) with increased toughness in callipyge lamb loins were also found (P<0.05). The results from the current study suggest that anti-apoptotic function of HSP would be likely involved in postmortem proteolytic systems and subsequent meat tenderization.