Effect of ultrasound pre-treatment modes on gelation properties of silver carp surimi

Abstract The aim of this study was to illustrate the effect of high intensity ultrasound (HIU) pre-treatment modes (HIU pre-treatment before salt-chopping (HIUBC), after salt-chopping (HIUAC) and after stuffing into polyvinylidene chloride casing (HIUAS)) on the gelation properties of silver carp surimi. HIUBC facilitated the protein dispersion and more compact microstructures formation, which was beneficial to obtaining the highest water-holding capacity (WHC) of HIUBC gels. Meanwhile, the puncture properties of HIUBC gels were significantly improved via the formation of more e-(γ-Glu)-Lys and S–S bonds. HIUAC and HIUAS promoted the formation of e-(γ-Glu)-Lys bonds, but also induced the protein degradation, as evidenced by the decreased solubility and relatively higher TCA-soluble peptides. Thus, no obvious improvement of puncture properties and WHC was observed for HIUAC or HIUAS gels. In conclusion, HIUBC was beneficial to facilitating protein dispersion, thereby improving gelation properties of surimi during heat-induced gelling process. However, HIUAC and HIUAS hardly influenced gelation properties of surimi. This might provide an effective method of HIU pre-treatment for promoting gelation properties of surimi.