Comprehensive analysis of ozone water rinsing on the water-holding capacity of grass carp surimi gel

The water-holding capacity (WHC) in surimi gel is a key factor that influences the quality and economic value of surimi-based products. This study investigated the effect of ozone water rinsing (1, 3, 5, 7, and 10 mg/L) on the WHC, gel microstructure, capillary pressure and protein-water interactions of grass carp surimi gel. Ozonation had entrapped water molecules within the gel matrix. The treatments improved gel strength and produced a homogenous microstructure of gels with smaller pore size. The contact angles in 1-10 mg/L ozone water treatments were significantly lower than that of the non-ozonated control. The gels of the 5 and 7 mg/L ozone water treatments had significantly higher capillary pressure and lower oxygen-deuterium peak area responses after hydrogen-deuterium exchange than that of other treatments and control. The ozone water-rinsed surimi gel had better WHC due to the oxidation modifications that promoted the cross-linking of myofibrillar proteins and the formation of a more hydrophilic gel network, which allowed the gel to immobilize more water molecules.