Identification of a modori-inducing proteinase in the threadfin bream: Molecular cloning, tissue distribution and proteinase leakage from viscera during ice storage

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

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.

A novel soft surimi gel with functionality prepared using alcalase for people suffering from dysphagia

In this study, effects of alcalase on physical properties, pepsin digestibility, and antioxidative activity in the heat-induced surimi gel were investigated to develop a novel gel product for people with dysphagia. The heat-induced gelation profile of surimi showed that alcalase activity was maximized at approximately 37 °C. The surimi gel attained an appropriate texture for people with dysphagia, when a combination of 0.3-0.5% alcalase and two-step heating at 37 °C and 90 °C was used. Adding alcalase effectively promoted proteolysis, resulting in softening of the gel. Furthermore, the gel with 0.5% alcalase showed improved pepsin digestibility, when heated at 37 °C and 90 °C. Its antioxidative activity was enhanced by adding 0.5% alcalase. Therefore, a combination of 0.5% alcalase and the two-step heating at 37 °C and 90 °C was useful in improving the physical and functional properties of the surimi gel for people with dysphagia.