大豆蛋白纳米颗粒皮克林稳定剂的结构特征及其结构化乳液缓释输送载体的构建

To deepen the knowledge about the structure-function relationships of soy proteins, as well as find their novel functionalities, is still an important subject in the food science and colloid fields nowdays, which is very important for extending the application of these proteins in food formulations. Recently the applicant found that soy protein isolate (SPI) shows a novel Pickering stabilization towards the emulsions. Based on the principles of protein-protein interaction and particle-stabilized emulsions, the present project is undertaken to further elaborate a kind of SPI nanoparticle Pickering stabilizers, and unravel the formation mechanism of gel-like Pickering emulsions and their potential to be applied as delivery systems for lipid-soluble bioactives. First, the preparation, structural characteristics and structure-activity relationships, as well as emulsifying and interfacial properties of SPI nanoparticle Pickering stabilizers, formed through thermal aggregation, enzymatic cross-linking and other processes, were investigated. Then, the formation process and mechanism of gel-like SPI Pickering emulsions were studied, by means of modulation of particle concentration, oil fraction or environmental parameters. Last, the encapsulation and controlled-release properties of these structured Pickering emulsions were characterized. The results and novel findings of this project will be of great importance not only to provide an effective solution strategy for the development of novel SPI products and functional foods, but also to enrich the colloidal chemistry theory of protein-stabilized emulsions.

深化大豆蛋白质的结构与功能相关性的科学认知，挖掘其新功能，仍是目前食品科学及胶体研究领域的一项重要课题，对拓宽其工业应用范畴至关重要。申请人新近发现，大豆分离蛋白(SPI)具有一种新型的皮克林乳化机制。本项目拟进一步从蛋白质相互作用原理及颗粒"皮克林"稳定理论出发，构建一类SPI纳米颗粒皮克林稳定剂，揭示相关结构化乳液的形成途径及其作为活性物质包埋输送载体的可能性。首先，表征热絮凝、酶交联及与其他物质复合等手段制备的SPI纳米颗粒的结构特征、构效关系，以及乳化与界面性质；其次，通过调控颗粒浓度、油相比例或环境因素，研究结构化SPI皮克林乳液的形成规律，进而从胶体化学角度揭示其胶凝机理；最后，探索此类乳液作为活性物质包埋缓释输送载体的实现途径及活性物质释出规律。研究结果不仅为研发功能性SPI及新型功能性食品提供一种有效的技术解决方案，而且对丰富目前有关蛋白稳定乳液的胶体化学理论具有重要意义。

食品级皮克林乳液的构建及表征是目前食品胶体领域的一个研究热点。研发食品级皮克林乳液的关键是找到适合于食品体系的皮克林稳定剂，而文献中报道中的性能优越的食品级皮克林稳定剂的种类仍非常稀少。本项目旨在揭示大豆蛋白在作为食品级皮克林稳定剂方面的实现途径及机理，以及相关皮克林乳液体系在研发新型功能性食品方面的潜在应用前景。基于此，本项目主要探索了多种物化方式使大豆蛋白（包括大豆分离蛋白及大豆球蛋白）转化为有效皮克林稳定剂的技术途径，进而研究了相应皮克林稳定剂的结构特征及构效关系，以及界面与乳化相关机理；借鉴物化胶体领域的研究方法，探索了结构化大豆蛋白颗粒稳定的皮克林乳液的形成规律，并揭示了相关胶凝机理；还验证了大豆蛋白皮克林乳液作为脂溶、热敏活性物质（以β-胡萝卜素作为代表活性物质）有效包埋级释输送载体的可能性，并研究了相关包埋缓释输送功能的调控机制。相关研究取得了系列重要的研究成果，包括：(1) 确证采用简单的加热处理即可使大豆分离蛋白及大豆球蛋白转化为一类性能优越的食品级皮克林稳定剂；(2) 一定的静电屏蔽作用可显著地改善大豆蛋白皮克林稳定剂的乳化效率及界面排列；(3) 采用微射流均质乳化技术可容易地获得一类流变性能及微结构可控的大豆蛋白皮克林乳液凝胶；(4) 大豆蛋白颗粒稳定的皮克林乳液凝胶作为一类具有潜在肠道靶向缓释功能的包埋输送载体。相关研究结果已发表于国际主流SCI期刊（如J. Agric. Food Chem., Food Hydrocolloids）共24篇（按最新影响因子计，总影响因子达108），获得1项教育部高等学校优秀成果奖自然科学奖二等奖。相关SCI论文已被国内外学者引用达304次，其中他人引用为252次。相关成果不仅对于研发高性能的食品级皮克林稳定剂（及食品皮克林乳液体系）具有重要的理论与实践借鉴意义，而且对于丰富蛋白质的乳化稳定机制的认识也有较为重要的学术价值。