Inhibitory effect of microwave heating on cathepsin l-induced degradation of myofibrillar protein gel

Abstract

This work was aimed to compare the effect of microwave (MW) heating on the cathepsin L (Cat L)-induced degradation of myofibrillar protein (MP) gels with that of water bath (WB) heating. First, Cat L from silver carp was purified and determined to be 45 kDa. The gel strength of the MW-heated MP gels were significantly higher than those of the WB-heated when Cat L was added (P < 0.05). The gel electrophoresis pattern and scanning electron microscopy analysis indicated that MW heating inhibited the Cat l-induced hydrolysis of MP gels. In addition, the number of sulfhydryl groups and surface hydrophobicity of MW-heated gels were lower than those of WB-heated gels when Cat L was added. These results indicated that MW heating could effectively weaken the degradation of Cat L on MP gels by manipulating disulfide bonds and hydrophobic amino acids, resulting in good gel properties and a compact protein network.