Effect of Smilax china L. starch on the gel properties and interactions of calcium sulfate-induced soy protein isolate gel.

Hydrocolloids have been widely used in the food industry as gelling agents, stabilizers and food thickeners to improve the viscosity, texture and stability of foods. Normally, individual polysaccharides or proteins do not form an excellent solid gel. Therefore, composite gels have received extensive attention. In this study, the effects of Smilax china L. starch (SCS) on the gel properties and interactions of CaSO4-induced soy protein isolate (SPI) gel was investigated. The gel properties of SCS-SPI gel system were analyzed by dynamic rheological, gel strength and water holding capacity. Synchronously, the interaction and microstructure of SCS-SPI gel system were evaluated by protein solubility and scanning electron microscope. Finally, the gel mechanism of the gel system was established. Viscosity, elasticity, gel strength and water holding capacity were obviously increased and microstructure become more compact of gel system and with the concentration increased of SCS. Furthermore, the result of protein solubility showed that hydrophobic, hydrogen bond and disulfide bond interaction play an important role on maintaining the gel system.