Study on in Vitro Digestion Characteristics of Pickering and Traditional Whole Nutrient Emulsion

In order to verify the effect of emulsifiers on the digestion of whole nutrient emulsion in vitro, three whole nutrient emulsions respectively containing octenyl succinic acid starch (OS), Zein, and phospholipids (PL) were prepared through shear and high-pressure homogenization. The pH-stat method was used to simulate the in vitro digestion process of whole nutrient emulsion, and the effects of OS, Zein Pickering emulsifier and PL traditional emulsifier on the digestion characteristics of whole nutrient emulsion were studied. The particle size distribution, zeta potential, microstructure, and lipid digestibility of whole nutrient emulsion during digestion were measured. The results showed that during the simulated digestion process, the particle sizes of the three emulsions showed a trend of first increasing and then decreasing, and the absolute values of zeta potential showed a trend of first decreasing and then increasing. After digestion, the potential values of OS emulsion, Zein emulsion, and PL emulsion were −14.53, −19.90, and −18.80 mV, respectively. The oil drops of Zein emulsion were most hydrolyzed by lipase and the final free fatty acid release rates of Zein emulsion, OS emulsion, and PL emulsion were 20.54%, 17.21%, and 14.29%, respectively. Pickering whole nutrient emulsion had a higher in vitro lipid digestion rate than traditional whole nutrient emulsion, which was conducive to the digestion and absorption of whole nutrient emulsion lipids and helped to improve the bioavailability of lipid soluble bioactive components in emulsion.