Application of soybean isolate protein (SPI) and soy hull polysaccharide (SHP) complex in fermentation products

We investigated the stability of a soy protein isolate (SPI)/soy hull polysaccharide (SHP) composite and its effect on the quality of fermented products. Sonication contributed to a more stable SPI/SHP composite. Increasing SHP concentrations increased the viscoelasticity of the emulsions and decreased turbiscan stability index (TSI) values, indicating that SHP improved the emulsification and stability of the composite emulsions. The fermented products with SHP had an increased ability to bind to water. Hardness, gelling, chewiness, sourness, and astringency increased with polysaccharide addition. Additionally, SHP promoted acid production by lactic acid bacteria during storage. All groups had viscoelastic behavior (G' ˃ G″, tan δ < 1), with viscosity increasing and subsequently decreasing. TSI values were significantly lower in the treated groups than in the control group. The results revealed that SHP improved the sensory quality and storage stability of fermented products.