Effect of CaCl2 in frozen surimi of Alaska pollack on cross-linking of myosin heavy chain in salted paste from the same material.

Five kinds of frozen surimi containing varied concentrations of CaCl2 (0-50mmol/kg) were prepared from Alaska pollack. The surimi was ground with 3% NaCl at the temperature below 8°C for 10 min. The salted paste thus obtained was incubated at 15°C or 30°C to induce setting (SUWARI). During the incubation, breaking stress (BS), solubility of protein in a medium containing SDS-urea-2-mercaptoethanol, and subunits composition of the soluble protein by SDS-PAGE were measured. As a result, it was shown that the BS of the paste hardly increased and the protein in the paste remained fairly soluble with a setting at 15°C. On the other hand, at 30°C, the BS of the paste increased significantly and the protein in the paste turned into insoluble. In addition, the rate of decrease in myosin heavy chains (HC) in the pastes indicated that a cross-linking reaction of HC strongly occurred at 30°C but not at 15°C. It was further found that the highest rates of increase in BS as well as of decrease in HC were obtained with the salted paste from the surimi containing 10-20mmol CaCl2 per kg. Decrease in HC in the paste containing 10 mmol CaCl2 proceeded three times faster than that of the paste without CaCl2. These results indicate that CaCl2 in the salted paste may enhance the gel (KAMABOKO) formation by acceleration of cross-linking reaction between myosin HCs.