1National Surimi Manufacturers Association, Abashiri, Hokkaido 093-0057, 2National Research Institute of Fisheries Science, Yokohama, Kanagawa 236-8648, 3Abe Jyuro Co.Ltd., Abashiri, Hokkaido 093-0004, Japan
Frozen surimis from walleye pollack, which contained 8% sorbitol and 8% sorbitol plus either 0.2% sodium polyphosphate or 3.0% NaCl, were ground with 3% NaCl (final concentration) and also with 0-0.25% K2CO3 to make the pH value between 6.8-8.7. The salt ground meat was preheated at 25°C for 8h, and subsequently heated at 90°C for 30m. The breaking strength (BS) and breaking strain (bs) of the heated gel were measured as a function of preheating time. The pH-dependence of the gel forming ability and the effect of polyphosphate salt on it were investigated from the time-dependent change in the measurements. The rate of increase in BS also with gel stiffness (Gs=BS/bs) was found to be the highest among the heated gels at around pH 7.5-7.8 when the frozen surimi with polyphosphate salt was applied, whereas the rate of increasing rate of BS and Gs of the heated gel from two lots of frozen surimi without polyphosphate salt was highest at around pH7.6-8.5. These results indicated that the most profitable pH condition for the heat-induced formation of gel from frozen surimi varied between the lots with and without adding polyphosphate salt.