基于界面分子的大豆蛋白乳状液酶解消化机理研究

Soy-protein emulsion plays a key role in building various foods, affects the digestion and absorption of foods, and even leads to physical health problems, the key to solve which is to clear changes of interfacial molecules and the mechanism of enzymatic digestion of emulsion. In this study soy protein isolate, as the main raw material, will be used to be prepared of emulsion with lipid, and the action, structure and configuration changes and their common nature of interfacial molecules (soy protein, mainly) in the system will be explored. By designing emulsions with digestive enzyme to take place hydrolysis reaction, we will research the interaction, conformational conversion，relocation and re-aggregation of interfacial molecules, as well as emulsion instability and characteristics of hydrolysis products during the reaction process, and analyze the mechanism of the enzymatic digestion of soy protein and lipid in interface environment. Through in vitro digestion test there will be changes revealed of soy protein emulsion in each analog gastrointestinal environment, and the mechanism generalized of in vitro enzymatic digestion. On this basis, controllable digestion-based soy-protein emulsion will be constructed to discuss the relationship of interface proteolytic digestion with the stability of the microspheres in emulsion and to illustrate the targeting release mechanism of the lipid molecule. This program implementation is expected to lay the theoretical foundation for further studying in vivo effective use and the relative safety of soy-protein foods.

大豆蛋白乳状液在构建各类食品中起着关键作用，影响食品消化吸收，甚至引发人体健康问题，而解决该问题的关键是明确界面分子变化规律与乳状液酶解消化机理。本研究以大豆分离蛋白为主要原料与油脂制备大豆蛋白乳状液，探讨乳状液中界面分子(主要是大豆蛋白)作用、结构及构象的变化规律与共性；设计乳状液与消化酶进行水解反应，研究酶解过程中界面分子相互作用、构象转换、重定位与再聚集，以及乳状液失稳、酶解产物特性，剖析大豆蛋白及油脂在界面环境下酶解机制；通过体外消化试验，揭示大豆蛋白乳状液在各模拟消化道环境下的变化规律，归纳其体外酶解消化机制；在此基础上，构建基于可控消化的大豆蛋白乳状液，探讨界面蛋白酶解消化与乳状液微球稳定性的关系，进而阐明油脂分子定点释放机理。本项目的实施有望为大豆蛋白类食品的体内有效利用与食品相对安全的深入研究奠定理论基础。

大豆蛋白乳状液在构建各类食品中起着关键作用，影响食品消化吸收，甚至引发人体健康问题，而解决该问题的关键是明确界面分子变化规律与乳状液酶解消化机理。本研究以大豆分离蛋白为主要原料与油脂制备大豆蛋白乳状液，设计乳状液与消化酶进行水解反应，并通过体外消化试验，探讨界面蛋白酶解消化机理，结果为：“乳化体系失稳-界面膜破坏-脂肪游离-蛋白再聚集-界面膜形成-油滴被包覆-乳化体系再次形成”是一动态消化过程。大豆蛋白质乳状液界面分子酶解反应与乳状液失稳及油脂分子释放是一个动态平衡关系。对于O/W型与W/O型乳液，二者在酶解消化过程中，最大的区别是前者不存在乳液体相的转变过程，而后者在胃阶段中后期已转化成O/W或W/O/W的过程，这明显地延缓了酶对乳液的作用。本项目的成果有望为大豆蛋白类食品的体内有效利用与食品相对安全的深入研究奠定理论基础。