THE ROLE OF SODIUM PYROPHOSPHATE IN GEL FORMATION AND CROSS-LINKING OF MYOSIN HEAVY-CHAIN OF SALT-GROUND MEAT FROM WALLEYE POLLACK

Frozen surimi from walleye pollack was ground with 2.5% NaCl together with/without 0.3% Na-pyrophosphate (PPi) and incubated at 10-60-degrees-C, followed by heating at 90-degrees-C for 20 min. The quality of setting and setting-heating gels thus prepared was evaluated as follows: (1) At 20-degrees-C and below, addition of PPi caused an appreciable decrease in the formation of cross-linked myosin heavy chain of larger molecular size, accompanied by an increase in breaking strain without changing the breaking strength of the setting-heating gel. (2) Essentially, At 40-degrees-C and over, the cross-linking reaction of myosin heavy chain of salt-ground meat was hardly observed. The addition of PPi suppressed such reaction further and reduced the formation of cross-linked myosin heavy chain. The breaking strength of heating gel formed from the same salt-ground meat inface decreased while its breaking strain increased with PPi. These results manifested that the effect of PPi on the production of setting gel and setting-heating gels depended considerably on the temperature and period for setting of salt-ground meat.