Effect of Non-sodium Salt Substitution on the Properties and Flavor of Coix Starch-Myofibrillar Protein Composite Gel

To investigate the effect of calcium, magnesium and potassium salts on the properties of coix seed starch-myofibrillar protein (CSS-MP) composite gel with low sodium content.

Based on the results of previous research, the effects of partial substitution of NaCl by CaCl₂, MgCl₂ or KCl on the gel strength, water holding capacity (WHC), rheological properties, surface hydrophobicity, sulfhydryl group content, gel microstructure and sensory evaluation of CSS-MP composite gel were investigated.

The texture and rheological properties of the CaCl₂ substitution group were better than those of the control group (3% NaCl), and the WHC and whiteness of the KCl substitution group were not significantly different from those of the control group, but the gel strength was decreased by MgCl₂ or KCl substitution. The total sulfhydryl content of the CaCl₂ and MgCl₂ replacement groups was significantly lower than that of the control group, and the surface hydrophobicity of the CaCl₂ replacement group was significantly higher than that of the other three groups. The addition of MgCl₂ promoted the formation of hydrogen bonds, enhanced the hydrophobic interaction, while CaCl₂ substitution had the opposite effect. In terms of sensory properties, the substitution of 1.0% CaCl₂ and 0.5% MgCl₂ could attain a saltiness perception similar to 3% NaCl. However, the comprehensive sensory score showed that the substitution of the three chlorine salts caused no significant difference in sensory properties of CSS-MP composite gel.

Calcium, magnesium and potassium salts can improve the properties of CSS-MP composite gel in different degrees. The results of this study lay a theoretical foundation for the development of low-sodium composite surimi gel products.