Emulsions co-stabilized by soy protein nanoparticles and tea saponin: Physical stability, rheological properties, oxidative stability, and lipid digestion

Herein, the effects of the concentration (0.1%-1.0%, w/v) and addition sequence of tea saponin (TS) on the physical stability, oxidative stability, rheological properties, and in vitro digestion of the emulsions stabilized by heat-induced soy protein isolate nanoparticles (SPs) were investigated. The results revealed that the concentration and addition sequence of TS have significant impact on the microstructure, stability, rheological properties, and in vitro digestion of the emulsions. TS was shown to not only fill the interfacial gaps but also adsorb on the particle surfaces, contributing to interfacial wettability. With increasing TS concentration, interfacial tension decay is clearly observed. Further, TS endows the droplets with electrostatic repulsion and steric resistance, preventing their flocculation, coalescence, and oxidation. Finally, in vitro digestion experiments demonstrated that the presence of TS delayed the lipid digestion of the emulsions.

Automated summary

The concentration and addition sequence of tea saponin (TS) have significant effects on the physical stability, rheological properties, oxidative stability, and in vitro digestion of heat-induced soy protein isolate nanoparticles (SPs) stabilized emulsions. TS not only fills the interfacial gaps and enhances interfacial wettability, but also provides electrostatic repulsion and steric resistance, preventing flocculation, coalescence, and oxidation of the droplets. In addition, TS delays the lipid digestion of the emulsions.