香料醛/乳清蛋白界面反应调控乳液凝胶结构、性能及应用研究

食品组分相互作用是食品科学领域的持续研究热点。传统研究集中于组分在水相中的相互作用，再进行界面修饰，而食品常为多相体系，在油/水界面上的组分互作及原位修饰研究相对欠缺，香料中脂溶性醛类成分与水溶性蛋白质间的界面相互作用关注较少。申请人前期研究证实，油相中肉桂醛与水相中乳清蛋白的界面反应能影响其乳液及凝胶的特性，但影响机制仍不明确。酸奶是一种含脂的弱凝胶态食品体系，析水/析乳清问题严重影响其品质和货架期，基于前期研究发现，项目突破性提出利用醛与乳清蛋白间界面反应来改善酸奶稳定性。首先系统研究界面反应对乳液凝胶结构、性能的影响，利用扩散波光谱等手段，探究其对乳液凝胶的界面调控过程；进而研究醛与乳清蛋白界面相互作用，并利用冷冻断裂电镜等技术表征界面形貌演变，阐明界面调控机理；研究醛对界面反应的构效和量效作用，构建结构性能可控的乳液凝胶，从而为酸奶产品析水/析乳清的行业共性问题提供新的理论指导。

Food component interaction is keeping a research hotspot in the field of food science. Traditional research focuses on the interaction of components in the aqueous phase, then using for the interfacial modification. Food is a multi-phase system. However, the study of components interaction at the oil/water interface and simultaneously interfacial modification is relatively weak. There is less concern about the interfacial interaction between the lipophilic aldehyde in flavors and hydrophilic protein. Our previous results confirmed that the interfacial reaction between cinnamaldehyde in the oil phase and whey protein in the aqueous phase could affect the characteristics of the emulsion and gel, but the influence mechanism is still unclear. Yoghurt is a weak gel-network food system, containing fat. Water and whey separation seriously affects the quality and shelf life of yoghurt. Based on our previous findings, we proposed that the interfacial reaction between aldehyde and whey protein could be used to improve the stability of yoghurt. Firstly, the influence of interfacial reaction on the structure and properties of emulsion gels will be systematically studied. The interfacial modulation on emulsion gel is investigated by using diffusing wave spectroscopy and other techniques. Then the interfacial interaction between aldehyde and whey protein will be studied. The evolution of morphology of interfacial layer is monitored by froze fracture electron microscopy and other techniques. Subsequently, the interfacial modulation mechanism is clarified. Finally, the structure- and dose-effect of aldehyde on interfacial reaction is studied. The emulsion gels with controllable structure and properties will be constructed. The obtained knowledge will provide the new theoretical guidance to improve the separation of water/whey in yoghurt, which is the common problem in dairy industry.