Abstract:The effects of ultra-high pressure (100~500 MPa) coupled with heat treatment (40 °C/30 min, 90 °C/20 min) on the gel properties and water migration of bighead carp (Aristichthys nobilis) surimi were studied. The changes in gel strength, water-holding capacity (WHC), whiteness, texture, microstructure, SDS-PAGE, and water migration of bighead carp surimi gel under different treatment conditions were investigated, and the correlations of these indicators with gel strength were analyzed. The results show that ultra-high pressure treatment coupled with heat treatment significantly improves the gel properties of bighead carp surimi. The gel strength and unit mass peak area of immobile water (A22) of the gel after ultra-high pressure treatment at 300 MPa/15 min followed by heat treatment (denoted as 300PH) were significantly higher than those of the other treatment groups (p<0.05). The gel strength and WHC of the 300PH sample were higher by 88.40% and 4.75%, respectively, than those of the samples subjected to traditional two-stage heat treatment. The indicators that were highly correlated with the gel strength of surimi gel were breaking force, depression depth, hardness, springiness, cohesiveness, chewiness, and A22. The unit mass peak area of bound water (A21) was moderately correlated with the gel strength of surimi gel. This indicates that 300PH formed a dense gel network structure, locked more bound water, and restricted the migration of immobile water to free water, thereby improving the properties of surimi gel. This research aims to provide data reference for industrial application of ultra-high pressure in the processing of surimi gel products and high-quality freshwater fish surimi products.
