Effects of exogenous lipids on gelling properties of silver carp surimi gel subjected to microwave heating

Lipids are important components of surimi products because they enhance the whiteness and flavor of food. The effects of three common types of exogenous lipids on the gel properties of surimi subjected to two different heating methods were investigated in this work, using frozen silver carp (Hypophthalmichthys molitrix) surimi as the raw material. The surimi gels were prepared by two-stage water bath heating or single-stage water bath heating followed by microwave heating. We found that the quality of surimi gels was in the order of lard > chicken fat/soybean oil, which may be associated with polyunsaturated fatty acid content. The surimi gel strength was reduced with an increase in the amount of lipid added. Microwave heating significantly increased the gel strength of surimi containing exogenous lipids when compared to conventional heating. Surimi gels prepared by microwave heating showed more denser protein network microstructures by scanning electron microscopy (SEM), suggesting aggregation of protein molecules. The findings of this study provide a theoretical basis for using microwave heating to generate surimi gels with exogenous lipids.