Effects of calcium and zinc ions injection on caspase‐3 activation and tenderness in post‐mortem beef skeletal muscles.

Summary: This study was designed to investigate the effects of Ca2+ and Zn2+ ions injection on post‐mortem tenderness and caspase activation by examining the expression of caspase‐3 and cytochrome c in post‐mortem beef skeletal muscles treated with Ca2+ and Zn2+. Results showed that Ca2+ ions injection accelerated post‐mortem tenderisation of beef skeletal muscles, whereas Zn2+ retarded the process. In the Ca2+‐injected samples, the level of caspase‐3 precursor decreased markedly without the production of activated caspase‐3, whereas the level of cytochrome c was increased markedly. So, Ca2+ possibly promoted caspases activation upstream of cytochrome c release, but inactivated caspase activity by calpain and/or fast depletion of ATP; whereas Zn2+ blocked the activation of procaspase‐3 with no visible change in the level of cytochrome c, and the block possibly resulted from its direct inhibition on caspase‐3 enzyme. [ABSTRACT FROM AUTHOR]