Internal/external Aqueous-Phase Gelation Treatment of Soybean Lipophilic Protein W/O/W Emulsions: Improvement in Microstructure, Interfacial Properties, Physicochemical Stability, and Digestion Characteristics

This study aimed to examine the effects of gelation on the stability and functionality of soybean lipophilic protein (LP)-stabilized W/O/W emulsions by gelating the internal and external aqueous phases separately. Xanthan gum, gum arabic, methylcellulose, and pectin were used to gel the internal/external aqueous phase of W/O/W emulsions. The measurements of particle size, zeta potential, emulsifying properties, interfacial tension, microstructure, physicochemical stability, and digestion characteristics revealed that the internal/external aqueous-phase gelation effectively reduced the interfacial tension of emulsions, the external aqueous-phase gelation improved the interfacial protein adsorption rate of emulsion (more than 78%), and the internal aqueous-phase gelation improved the encapsulation efficiency of emulsion (more than 90%) and internal aqueous-phase retention (more than 85%). Meanwhile, both gelation treatments improved the digestion performance of emulsions, achieved the sustained release of entrapped materials, and improved their bioavailability. Briefly, the internal/external aqueous-phase gelation enhances W/O/W emulsion stability. This study enriched the means to improve the stability of W/O/W emulsions, which benefited the application and innovation of W/O/W emulsions in food processing.