The Mechanism of Improved Thermal Stability of Protein-enriched O/W Emulsions by Soy Protein Particles with Anti-aggregation Property

Growing interest in nutritional and functional foods has motivated the design of protein-enriched products in food industry, which, however, is greatly challenged by undesirable aggregation and gelation of proteins induced by heating from pasteurization process. In this study, we reported the preparation of heat-stable soy protein particles (SPPs) by a simple preheat process (100 °C for 30 min) at pH 6.2 and 0.5% (w/v) protein concentration. As a proof-of-concept, the thermal stability of high-protein emulsions prepared by SPPs compared to native soy proteins (SPs) were investigated. Results showed that high-protein emulsions stabilized by SPPs exhibited appreciable heat stability whereas SPs gelled when both samples were tested at an identical concentration (10%, w/v). In addition, the emulsions prepared by SPPs demonstrated lower values of storage modulus and viscosity in relationship with stabilized size by heat treatment as well as more stable coated protein layer, in contrast to those prepared by SPs presenting macroscopic aggregation and instable coated protein layer. The results would provide valuable information in terms of the development of heat-stable, high-protein, and well-dispersed food emulsions that may find numerous applications in food industry.