Low-Level Pressure Coupled Two-Stage Heat Treatment Improves Gel Properties and Water Migration of Aristichthys...

This study investigated the mechanism of the effect of low-level pressure coupled two-stage heat treatment (OPH treatment) on the gel properties and water migration of Aristichthys nobilis surimi based on myosin, and compared it with optimal single ultra-high pressure treatment (OP treatment) and traditional two-stage heat treatment (H treatment). The results showed that OPH treatment increased gel strength by 83.51% and 49.87% compared to H and OP treatments, respectively. The water-holding capacity (WHC) was 8.97% higher than in H-treated samples, and showed no significant difference from OP-treated surimi gels. Whiteness also improved by 1.22% and 10.26% relative to H and OP treatments. Compared with OP and H treatment, OPH treatment induced structural changes in myosin, leading to a reduction in α-helix content, an increase in β-sheet content, and exposure of internal hydrophobic groups. These changes enhanced hydrophobic interactions and disulfide bond formation, reduced the absolute zeta potential value, modified particle size, and promoted myosin aggregation, resulting in a more compact gel network structure. The compact structure retained more water molecules, which improved gel properties. The results confirmed that OPH treatment improved the gel properties to the greatest extent, and it could play an important role in improving the gel properties of surimi.