The phytosterol emulsion stabilized with soybean seed oil bodies: physical stability, rheological properties and gastro-intestinal digestion

The effective development and utilization of phytosterols are of great practical significance for human health. Soybean seed oil bodies (SSOBs), as a natural nanometer-scale raw material with inherent properties, can be used as an effective carrier for phytosterols. In this study, a new functional phytosterol emulsions (PEs) was stabilized with SSOBs, and its physical stability, rheological properties, gastrointestinal digestion, and release behavior were systematically investigated. The results showed that 5 wt.% SSOBs used for stabilizing PEs exhibited better phytosterol encapsulation efficiency (75.51%) and a smaller droplet size (2.55 μm). PEs stabilized with 5 wt.% SSOBs showed greater stability at salt concentration of 300–400 mmol/L or pH 8.0, which belonged to the pseudoplastic fluid, a type of non-Newtonian fluid. With the extension of digestion time, the number of large droplets in PEs decreased, the protein content gradually decreased, and the release rate of free fatty acids and phytosterols continuously increased during the simulated intestinal fluid digestion stage, reaching 67.45 μmol/mL and 65.35%, respectively. Therefore, SSOBs can serve as a novel transport carrier for lipophilic bioactive substances, and provide a theoretical basis for making plantsterols a promising ingredient with widespread use in functional food or pharmaceuticals.