蛋白质颗粒的界面组装、大变形流变及对乳液风味控释的影响研究

The interfacial behavior of protein particles is a key factor affecting the stability and functional performance of protein-stabilized emulsions, which could be applied as a potential strategy to control the release of flavor compounds in emulsions. In this project, based on the dominated role of the interfacial properties on emulsion functionality, the assembly of protein particles at oil-water interface was first tuned by the use of natural small molecules, which can modify the properties of particle surfaces. Then, the particle-laden fluid interfaces with different structural properties were constructed by using these protein particles, with the aim to improve the stability of protein emulsion systems and control their flavor release. The detailed works were described as follows: ①Fabrication and surface modification of protein particles were carried out, and then the interactions between particles and natural small molecules were measured. ②Dynamic assembly, large-deformation rheology and interactions of protein particles at the interface were studied by combining drop shape analysis tensiometry, Langmuir-Blodgett technique, large-amplitude dilatation/shear rheology, as well as multi-scale interface imaging spectroscopy. The aim of this part is to analyze the nonlinear rheological response of protein particle-laden interfaces in terms of interfacial microstructure and particle-particle interactions. ③Storage and drying stabilities of these protein particle-based emulsions were evaluated. Subsequently, the interfacial diffusion/binding and release kinetics of volatile flavor compounds in emulsions were monitored in a simulated oral environment. This project would establish the relation between the interfacial properties of protein particles and emulsion stability as well as functional flavor release, which could provide a promising strategy to develop novel protein emulsion-based delivery systems with controlled flavor release for healthy foods.

蛋白质颗粒的界面活性及界面组装决定着蛋白乳液的稳定性及功能性表现，有望为解决蛋白乳液风味的可控释放问题提供新思路。本项目从界面结构操控乳液功能的学术角度入手，探索通过表面修饰调控蛋白颗粒的油-水界面组装行为，构建不同结构特性的颗粒界面层，以实现蛋白乳液稳定性改善及风味释放的有效调控。研究内容包括：（1）蛋白颗粒的制备、天然小分子表面修饰及相互作用；（2）蛋白颗粒界面的大变形流变、微观结构及界面颗粒相互作用；系统表征蛋白颗粒的油-水界面组装动力学，重点利用大变形界面流变耦合多尺度界面成像光谱技术建立颗粒界面的非线性机械响应、微结构与界面颗粒相互作用之间的关联；（3）蛋白颗粒乳液的稳定性及风味物质在模拟口腔环境下的跨界面扩散、结合及释放动力学。本项目将揭示蛋白颗粒的界面组装及界面结构对乳液稳定及风味释放特性的操控机制，为现代健康食品研发新型的蛋白乳液基风味控释材料提供理论指导和技术解决方案。

食品级纳微结构单元的界面活性及界面组装决定着多相食品胶体材料的稳定性及功能性表现。本项目通过利用食品蛋白（肽）、天然两亲小分子的自组装和相互作用，构筑纳米胶体颗粒、纳米纤维等多类型结构单元，进一步利用这些结构单元在体相及界面的多维组装构建具备优越稳定性、环境响应能力等先进特性的乳液/乳液凝胶、泡沫等复杂结构化食品软材料，以实现其在风味与活性包埋/控释、脂肪替代、摩擦润滑等食品、药品及化妆品领域应用。主要研究内容包括：（1）食物蛋白（肽）纳米颗粒、纳米纤维的自组装、结构表征及相互作用；（2）纳米结构单元的界面组装行为及纳米皮克林乳液、乳液凝胶等胶体体系的制备、表征与性能调控；（3）多相食品软材料的界面稳定性机制及其与油脂结构化、活性物包埋与控释等宏观功能特性之间的内在关联。研究结果明确了胶体颗粒、纤维等界面组装行为及界面结构对多相胶体稳定及功能特性的影响机制，揭示界面结构操控与设计（Engineered interface）在研发多功能胶体材料上的重要性，建立了多相食品软材料的界面稳定性机制及其宏观功能特性之间的关联性，可为现代健康食品的研发提供重要技术解决方案。