Effect of setting temperature on the mechanical properties of surimi gels

As is well-known, the mechanical properties of surimi gels are improved by incubation at moderate temperatures (low temperature setting: LTS) prior to high temperature treatment (high temperature setting: HTS). In this study we investigated the effect of the setting temperature on the mechanical properties of surimi gels. To this end, the temporal development of the dynamic modulus during the setting process was investigated at various temperatures. The dynamic modulus of the surimi paste increased with time at low temperature treatment (5 and 10°C). However, this trend reversed at higher temperatures (25 and 30°C). The mechanical properties of the thermal gel, which was heated to 90°C after LTS, were also investigated. In this case, the sample treated at 10°C prior to HTS showed the most rigid property. The protein extracted from both the set surimi paste and thermal gel was analyzed by sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS–PAGE). This analysis revealed a relatively high actin content in the thermal gel set at 10°C. Two important findings emerged from the study; the setting temperature at which the gel acquires its most desirable textural properties is not the commercial setting temperature, and actin appears to play an unexpected role in the gelling mechanism.