Physicochemical and Oxidative Stability of a Soybean Oleosome-based Emulsion and Its in Vitro Digestive Fate As Affected by (-)-epigallocatechin-3-gallate

Oleosomes, which are pre-emulsified oil bodies found naturally in plants, have excellent stability, therefore making their use more popular in the food industries. However, the mechanism of EGCG in regulating the physicochemical and oxidative stability, and digestion of oleosome emulsions is not yet clear. In this study, the effect of EGCG on the properties of soybean oleosome emulsions (SOE) was examined at different pH values (5.0, 7.0, and 9.0). EGCG was significantly more effective in maintaining the stability of SOE at pH 5.0 and 7.0 over the 14 days of storage, but less effective at pH 9.0. Furthermore, lipid oxidation of SOE at pH 7.0 was successfully retarded by incorporating EGCG, but not at pH 5.0 and 9.0. The in vitro gastrointestinal results suggested that EGCG retarded the digestion rate of SOE based on a 20% reduction in free fatty acid release. The results of this study will help food technologists to design slow-digestive oleosome-based products that will satisfy health-conscious consumers' demand for healthier food choices.