Thermal gelation of salted paste from scallop striated adductor muscle

Abstract

: Salted muscle paste containing 60–100 mg protein/g paste and 0.5 M NaCl at pH 7.0 was prepared from fresh scallop striated adductor muscle and its heat-induced gelling characteristics were examined in order to produce invertebrate kamaboko-like foods. The heating of the paste to 90°C formed a weak gel. The setting effect on the gelation of the paste was introduced by incubation at 25°C for up to 4 h and was greatly strengthened by the addition of 10 mM Ca2+ due to the activation of an endogenous transglutaminase that preferentially cross-linked myosin heavy chains, but not actin and paramyosin. As a result, the texture of the gel produced by a two-step heating method was almost the same as that of a commercial fish kamaboko. It was also observed that the thermal gelation profile of scallop muscle paste was similar to that of fish myosin, rather than that of actomyosin, by means of a dynamic rheological measurement. Paramyosin also contributed to a characteristic increase in the G′ (storage modulus) value over the thermal gelation process and raised the G′′ (loss modulus) value around 65°C. The G′′ increase resulted in a slightly rigid texture of heated scallop gel. Isolated paramyosin demonstrated a characteristic thermal gelation profile showing a two-step increase in G′ and G′′ values, independent of Ca2+ concentration. The higher NaCl and protein concentrations were required to produce stronger and more elastic gels.