Influence of gender and spawning on thermal stability and proteolytic degradation of proteins in Australian red claw crayfish (Cherax quadricarinatus) muscle stored at 2 °c

Thermal stability and proteolytic degradation of male (M), nonspawning female (F) and spawning female (SF) red claw crayfish (Cherax quadricarinatus) muscle proteins during refrigerated storage (2 °C) were investigated. The thermal transition temperatures (Tmax) of myosin and actin remained relatively constant during storage, but their enthalpies of denaturation (ΔH) increased, especially in SF samples. SF muscle proteins were more heat-stable (greater Tmax and ΔH values, P < 0.05) than M and F muscle proteins. Protein degradation occurred in all muscle groups, more rapidly in M and F muscles than in SF muscle. The diminishments of a 69-kDa component and troponin-I and the appearance of a 55-kDa polypeptide represented the most salient proteolytic changes. The results suggested that the spawning status was a more significant factor than gender in affecting the quality of red claw muscle proteins and their changes during refrigerated storage.