金针菇多糖对大豆分离蛋白凝胶的增强作用及其结构表征

通过将金针菇多糖（Flammulina velutipes polysaccharide，FVP）添加到大豆分离蛋白（soy protein isolate，SPI）水凝胶中并进行热处理以提高SPI水凝胶强度、持水性和热稳定性。通过对二三级结构及分子间作用力的检测，进一步分析FVP-SPI水凝胶的稳定性。结果显示：热处理及添加FVP显著提高SPI水凝胶的持水能力，热变性焓ΔH提高了25.46%，水凝胶稳定性显著提高。疏水相互作用、二硫键和静电相互作用是形成热处理FVP-SPI水凝胶的主要作用力。FVP的加入提高了静电相互作用，使水凝胶中α-螺旋向β-折叠转变，SPI中色氨酸暴露于表面，疏水性增强。FVP对SPI水凝胶的增强作用为SPI水凝胶的开发应用提供一定参考。

Enhancing Effect of Flammulina velutipes Polysaccharide on Gelation Properties of Soybean Protein Isolate and Structural Characterization of Mixed Gels

Flammulina velutipes polysaccharide (FVP) was added to soy protein isolate (SPI) hydrogels and subjected to heat treatment to improve the gel strength, water-holding capacity and thermal stability. The stability of FVP-SPI hydrogels was further analyzed in terms of their secondary and tertiary structures and intermolecular forces. The results showed that heat treatment and addition of FVP significantly improved the water-holding capacity of SPI hydrogels, and increased the enthalpy change of denaturation (ΔH) by 25.46%, thereby significantly improving hydrogel stability. Hydrophobic interactions, disulfide bonds and electrostatic interactions were the major driving forces for the formation of heat-induced FVP-SPI hydrogels. The addition of FVP improved the electrostatic interactions and caused transformation of α-helix into β-sheets in the hydrogels, surface exposure of the tryptophan residues in SPI and enhanced hydrophobicity. The enhancement of SPI hydrogels by FVP provides a reference for the development and application of SPI hydrogels.