Gel properties of refrigerated silver carp surimi sol as affected by cold-induced sol-gel transition and shearing

Abstract

In this study, the effect of different temperatures (4 °C and 10 °C) on the physicochemical properties of surimi sol was investigated during various storage time (0–7 d). In addition, the water distribution, gel properties and microstructure of gels prepared from treated surimi sol, both with and without shearing, were analyzed. The results showed a continuous increase in the gel strength of surimi sol, indicating a sol-gel transition occurred. Notably, there was a significant decrease (P < 0.05) in protein solubility and the formation of sol network structures, suggesting protein cross-linking and aggregation after cold storage. The analysis of chemical bonds content and gel electrophoresis pointed to the involvement of disulfide bonds and hydrophobic interactions in protein cross-linking. Furthermore, the cold-induced sol-gel transition adversely affected the quality of heat-induced gel, and this deterioration was exacerbated by shearing before cooking. Compared to the unsheared group, shearing before heating resulted in a more pronounced texture and cooking loss in the sheared group, with the heat-induced gel exhibiting a more disordered and rougher surface. These findings shed light on the importance of controlling the cold storage process and shearing treatment to maintain the desired quality of heat-induced gel in surimi sol applications.