Proteolytic action of caspases 3 and 7 on the hydrolysis of bovine and porcine muscle myofibrillar proteins

The conversion of muscle into meat occurs immediately after animal slaughter and implies numerous biochemical reactions that nowadays are far to be fully understood. Research carried out during the last years has demonstrated that one of the first events occurring in postmortem muscle is the onset of cellular death or apoptosis (Ouali et al. 2006). This process is mediated by a particular group of enzymes called caspases. Triggering of this phenomenon would have important consequences for the rest of other better known processes occurring postmortem, such as the establishment of rigor mortis due to ATP depletion and the breakdown of the myofibrillar structure due to the action of several proteolytic enzyme groups. The final consequence will be the reduction of the mechanical resistance of meat, thus giving rise to tender meat (D’Alessandro et al. 2012). One of the main problems that meat industry has to face is inconsistency of the final meat tenderness, together with the impossibility to explain and predict this variability. In an effort to better understand the postmortem proteolysis of myofibrillar proteins by muscle peptidases and its relation to the development of meat tenderness, the present work had the objective to evaluate the potential action of executioner caspases 3 and 7 on the degradation of different myofibrillar proteins.