Breakdown of connectin during cooking of meat

Light-scattering studies on extracts of meat have confirmed the heat-induced breakdown of connectin previously observed by SDS gel electrophoresis. Because of the high subunit MW (∼10(6)) of connectin, the weight-average molecular weight of whole muscle undergoes a relatively large decrease when connectin is broken down during heating of meat. In cold-shortened muscle, breakdown of connectin by proteolysis was as rapid as in control samples, suggesting that connectin exists in an exposed environment rather than as a core to thick filaments. The breakdown of connectin during heating at 60 or 80°C for 40 min was more extensive than during ageing for 3 weeks at 2°C. Hence, the partial proteolysis of connectin during storage at 2°C is unlikely to be responsible for tenderisation induced by ageing.