复合界面对食品乳液中脂肪消化的影响

以中链甘油三酯为油相制备乳液，将天然高分子与小分子表面活性剂复配，构建阿拉伯胶（gum arabic，GA）或乳清分离蛋白（whey protein isolate，WPI）与吐温80（T80）的复合乳液界面。采用逐层添加或混合添加的方式，调控界面组分的吸附次序，构建不同界面结构的乳液体系。采用体外模拟小肠消化模型和界面流变技术等手段剖析乳液界面结构对脂肪消化速率的影响。结果表明：对于GA、WPI和T80形成的单一乳液体系，GA和WPI的界面弹性模量高于T80界面，黏弹性好。三者抗胆盐取代和延缓脂肪消化能力依次为GA＜WPI＜T80。在大分子GA或WPI与小分子T80形成的复合乳液体系中，由T80吸附占主导的界面，其延缓脂肪消化和界面抗胆盐取代的能力优于GA或WPI与T80共同吸附的界面结构。

Effect of Complex Interface on Lipid Digestion in Food Emulsion

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.