Histatin 5 affected the tenderness of braised beef by regulating calpain-2 activity in semimembranosus muscle during aging post-slaughter.

Abstract

This study aimed to determine whether histatin 5 affects the tenderness of beef and any associated mechanism. The results showed that histatin 5 (0-2.5 μM) concentration had different effects on the activity of calpain-2 in beef semimembranosus muscle, under different concentrations of Ca2+ in the incubation solution. At 0 mM or 40 mM Ca2+ in the incubation solution, 1 μM of histatin 5 induced autolysis, increased proteolytic activity of calpain-2, resulting in increased degradation of myofibrillar desmin in the muscle. Compared with the control group, incubation with 1 μM histatin 5 combined with 40 mM Ca2+ for 24 h had no effect on cooking loss or the thermal shrinkage rate of braising beef, but increased myofibrillar fragmentation in beef during incubation, which reduced the shear force and hardness of braising beef. This study provides a potentially new approach for improving the tenderness of braised beef.