Effects of the Hydrophobicity of Polysaccharides on the Properties of Surimi Gel

To process high-quality surimi products, this study investigated the effect of adding polysaccharides with five different degrees of hydrophobicity (contact angles of oligofructose, inulin, potato starch, glutinous rice starch, and wheat fiber were 19.2°, 30.2°, 39.1°, 72.8°, and 101.9°, respectively) to surimi on its gelation properties. The results showed that with the increase in the hydrophobicity of polysaccharides, the strength, hardness, elasticity, chewability and water-holding capacity of surimi gel increased first and then decreased. When adding potato starch with a contact angle of 39.1°, the values of above indicators are the highest, which increased by 26%, 14%, 1.02%, 10%, and 8% compared to the blank group without added polysaccharides, respectively. The brightness (L*) and whiteness of surimi gel decreased with the increase in the hydrophobicity of polysaccharides. In addition, the denaturation temperature and enthalpy value of myosin in surimi first increased and then decreased. Likewise, the degree of transformation of protein secondary structure in surimi gel from α-helix to β-sheet, the intensity of chemical forces (ionic bonds, hydrophobic interactions, and disulfide bonds), and the density of the network structure all increased first and then decreased. Overall, when adding polysaccharides with a contact angle of around 40° most effectively improved the gelation properties of surimi.