蛋清蛋白皮克林乳液稳定剂的可控制备技术及作用机理研究

Pickering emulsion is stabilized by solid particles adsorbed onto the oil/water two-phase interface. With good stability and controlled release properties, it has broad applications in food industry. Pickering emulsion stabilizer made from natural resources proteins presents enormous potential in application, however the preparation of protein stabilizer cannot be controllable yet and and its functional mechanism in emulsion is not clear. In this project egg white protein was used as raw material to induce the formation of microgel particles by acid heating, dry heating and pulsed electric field, etc. The formation mechanisms, molecular evolution mechanisms of microgel particles and the relationship between induction parameters and particle features were studied. Then the microgel particles based on multi features were applied to the preparation of three kinds of stabilizer typical Pickering emulsion (nanoemulsion, semi-solid emulsions, oil glue). The functional mechanism of microgel particles in different emulsion systems and correlation between particle features and emulsion characteristics was investigated. And the pertinence of induction mode, microgel particles features and emulsion was analysed to build an “induction parameters - microgel features - emulsion characteristics” model. Thus the preparation of Pickering emulsion stabilizer applied in various emulsion systems was finally controllable, to provide theoretic support for the applications of protein stabilizers in food processing.

皮克林（Pickering）乳液是一种由吸附到两相界面的固体颗粒稳定的乳浊液，具有良好的稳定性和控释性，在食品工业中具有广阔应用前景。以蛋白质为原料制备Pickering稳定剂具有巨大的应用潜力，然而目前蛋白类稳定剂制备方法尚缺乏可控性，其在乳液中的作用机理也不明确。本项目以蛋清蛋白为原料，采用酸热、干热、脉冲电场等不同诱导方式制备微凝胶颗粒，确定颗粒的形成机理与演化分子机制，分析诱导参数与颗粒特征的相关性；进而以多特征微凝胶颗粒为稳定剂制备3类典型Pickering乳液（纳米乳液、半固体乳液、油胶），阐明微凝胶颗粒在不同乳液体系中的作用机理，研究颗粒特征与乳液特性的相关性；综合分析诱导方式、微凝胶颗粒特征、乳液特性之间的关联，构建耦合式“诱导参数-微凝胶特征-乳液特性”模型，最终实现针对不同乳液体系的Pickering稳定剂的可控制备，为拓展蛋白类稳定剂在食品加工中的应用提供理论支持。

采用酸热诱导、干热改性、微波改性和糖接枝的方法调控蛋清蛋白微凝胶颗粒的形态和尺度，制备了系列具有典型纤维状、球状和团聚装的蛋清蛋白胶粒。研究了不同蛋清蛋白微凝胶颗粒的理化性质、界面吸附性能和乳化特性，明确了蛋清蛋白微凝胶颗粒特征与其乳化性能之间的关联。将制备的蛋清蛋白微凝胶颗粒用于纳米乳液、高内相乳液和油凝胶制备，并探索了在实际食品体系中的应用特性，发现不同颗粒构建的应用体系在物性特征上存在较大差异，与颗粒自身尺寸、形态及蛋白分子间相互作用强弱有着密切关联。项目最终验证了制备的蛋清蛋白微凝胶颗粒在营养素递送、脂肪替代和体系增稠方面的应用效果，为拓展蛋白类胶体颗粒在食品体系中的应用提供了理论指导。