Protein interactions and rheological properties of heat-induced gels containing soy and water-soluble mealworm (Tenebrio molitor larvae) protein mixtures

Abstract

This study investigates the protein interactions, rheological properties, and gel characteristics of complex protein gels prepared using varying ratios of soy protein isolate (SPI) and water-soluble mealworm protein (WS-MP). After heat treatment, the particle size increased for all ratios, and the absolute zeta potential exhibited a decreasing trend with higher WS-MP ratios. A comparison of SDS-PAGE profiles before and after heating indicated that disappeared bands may be associated with gelation. Furthermore, as the WS-MP ratio increased, the dominant molecular forces within the gels shifted from hydrophobic interactions and disulfide (SS) bonds to ionic and SS bonds. The SS content decreased as the WS-MP ratio increased. The surface hydrophobicity displayed an initial decrease followed by increased gels. Rheological analysis revealed that gel elasticity decreased as the WS-MP ratio increased, although no significant difference in gel elasticity was observed when the WS-MP ratio exceeded 50%. Heat-induced gels with different SPI:WS-MP ratios exhibited different color and turbidity characteristics. Heat-induced gels comprising the SPI:WS-MP mixture exhibited lower hardness and gumminess than single SPI and WS-MP heat-induced gels. Furthermore, the water holding capacity and the uniformity of gel microstructure exhibited a decreasing trend with an increasing WS-MP ratio. In conclusion, the results suggest that WS-MP can enhance the texture of SPI gels, with the optimal ratio depending on the desired gel properties.