Research on the preparation of soy protein isolate and whey protein isolate composite nanoparticles and their characteristics in high internal phase Pickering emulsions

This study investigated the role of thermal drive in the formation of soy protein isolate and whey protein isolate (SPI–WPI) complexes, as well as the stability effect of SPI–WPI complexes on high internal phase Pickering emulsions (HIPPEs). The shift in the peaks in the infrared spectrum and the change in fluorescence intensity indicated the interaction between these two proteins, which implies that SPI–WPI is not two dispersed groups of particles. Maximum emulsification activity (10.65 m²/g) and the absolute value of potential (37.87 mV) were achieved at an SPI to WPI mass ratio of 7:3. As the concentration and pH of the SPI–WPI complex increased, the droplets become evenly uniform and compact. It is predicted that the high concentration conditions are more favorable for the formation of a gel network structure. This research provides an effective strategy for HIPPEs stabilization using complex proteins.