Effect of CaCl2 on gel forming ability and cross-linking reaction of myosin heavy chain in salt-ground meat of skipjack tuna, carp, and walleye pollack

Salt-ground meat of skipjack tuna, carp, and walleye pollack containing 0-20 mmol CaCl2/kg was incubated at 10-40°C for setting. During incubation, changes in breaking strength and the subunit composition of the myofibrillar protein of the setting gel were examined. The gel formation and the cross-linking reaction of the myosin heavy chain (HC) of the salt-ground meat were promoted by the addition of CaCl2. CaCl2 exerted its effect by increas-ing the HC polymers during setting of skipjack tuna and carp salt-ground meat. On the other hand, CaCl2 stimulated the formation of large size HC polymers in walleye pollack meat, which were components corresponding to HC polymers too large to be solubilized into SDS-urea buffer. Moreover, the degree of the stimulatory effects of CaCl2 on gel formation and the cross-linking reaction of HC of the salt-ground meat was found to be in the order of skipjack tuna>carp>walleye pollack, from largest to smallest. This order was essentially the same as for the thermal stability of the myofibrillar protein for these fish species.