Abstract: In this study, emulsion was prepared with medium-chain triglyceride (MCT) as oil phase, and gum arabic (GA), whey protein isolate (WPI) and Tween 80 (T80) as emulsifiers to design complex emulsion interface. The interfacial structure of emulsions was varied by controlling the sequence of adsorption of the components at the interface using layer-by-layer adsorption or mixed adsorption. The effect of interfacial structure on the rate of lipid digestion was evaluated using a simulated intestinal lipolysis model by interfacial rheology. The results showed that individual GA or WPI interface presented higher interface modulus than T80 interface along with good viscoelasticity, and the ability to resist bile salt displacement and delay lipid digestion was as follows: GA < WPI < T80. In complex emulsions, the interface dominated by T80 showed a better ability to delay lipolysis and resist of bile salt displacement than the interface composed of GA (WPI) and T80.

Key words: emulsion, lipid digestion, complex interface, interfacial structure