基于脂肪结晶的皮克林乳液界面调控其功能输送特性的机制研究

The research and development of functional foods have become the focus of food science, food industry and general public. This project intends to introduce fat crystal into the Pickering emulsion delivery system, and proposes a new idea of regulating the delivery characteristics of Pickering emulsion by introducing the controllability of fat crystal in the gastrointestinal tract. In order to grasp the intrinsic control mechanism of functional components delivery of fat crystal-stabilized Pickering emulsion with interfacial layer as the research goal, the effects of fat crystal structure on the interface properties of the Pickering emulsion were investigated. Modern analytical methods were used to study the structural changes and nutrient release of the Pickering emulsion in the gastrointestinal tract. The effects of fat crystal structure on the functional components delivery characteristics of the emulsion were investigated. The relationship between the fat crystal structure, the interface properties of the emulsion and the digestion behavior was discussed to find the key interface characteristics and intrinsic mechanism of functional components delivery of fat crystal-stabilized Pickering emulsion with interfacial layer, to establish and the relevant model and to realize the rational design of the interface and effective control of nutrient delivery of Pickering emulsion. The research results of this project provide scientific basis for the accurate and stable nutrient delivery of fat crystal-stabilized Pickering emulsion, and guide the design of healthy delivery products more accurately and effectively.

功能性食品的研发已经成为当今食品基础科学、食品工业及普通大众的关注热点。本项目拟将结晶脂肪引入皮克林乳液输送系统，提出通过引入结晶脂肪在胃肠道消化的可控性，从而调控其皮克林乳液功能输送特性的新思路。以掌握脂肪结晶皮克林乳液界面调控其功能输送特性的内在机制为研究目标，系统地考察脂肪结晶结构对其乳液界面性质的影响。借助现代分析手段及方法研究肪结晶皮克林乳液在消化过程中结构变化规律及营养素释放规律，探讨脂肪结晶结构对其乳液的功能输送特性的影响。关联脂肪结晶结构、乳液界面性质与消化行为的关系，找到脂肪结晶皮克林乳液界面调控功能输送特性的关键性界面特征和内在作用机制，建立相关模型，实现对功能性脂肪结晶皮克林乳液界面的合理设计和营养素输送的有效调控。本项目的研究成果为脂肪结晶皮克林乳液准确稳定输送营养素提供科学依据，更精确有效地指导功能性食品的设计加工。

功能性食品的研发已经成为当今食品基础科学、食品工业及普通大众的关注热点。本项目将结晶脂肪引入皮克林乳液输送系统，提出了利用结晶脂肪在胃肠道消化的可控特性调控其皮克林乳液功能输送特性的新思路，以全氢化植物油等高熔点脂质为研究对象，通过调整加工条件、乳化剂种类（小分子非离子型、蛋白型）和浓度成功地构建了一系列具有不同结晶结构的脂肪结晶颗粒及其皮克林乳液，并系统地考察了脂肪结晶结构对颗粒界面自组装行为及其乳液界面性质的影响，掌握了脂肪结晶皮克林乳液在消化过程中结构变化规律及营养素释放规律，探讨了脂肪结晶结构对其乳液的功能输送特性的影响并建立了相关模型。.研究结果表明，超声功率的增加会使得脂质结晶颗粒（SLNs）平均粒径增大以及β型和球状晶体增多，超声时间的增加会使得SLNs平均粒径显著减小但形态晶型无显著性变化。与蛋白型乳化剂相比，小分子乳化剂形成的SLNs平均粒径较小、电位值较低且亲水性较强，但所制成的乳液平均粒径较大、界面膜和界面结晶层较厚；随乳化剂浓度增大，添加小分子乳化剂的SLNs中α晶型逐渐减少伴随β晶型逐渐增多、形态由宽板状逐渐变为小短板状，所制成的乳液平均粒径逐渐减小、乳液液滴的界面膜和界面结晶层厚度增加；而添加蛋白型乳化剂的SLNs随着乳化剂浓度增大粒径较为稳定、接触角逐渐减小、晶型保持α型不变、形态从大球状变为小球状，所制成的乳液液滴界面膜和界面结晶层厚度先逐渐增加后稳定。处理温度的升高使得小分子乳化剂稳定的SLNs转变为不规则棒状的β型晶体，而蛋白稳定的SLNs仍然以α型球状为主。蛋白稳定的SLNs形成的乳液稳定性强于小分子乳化剂SLNs稳定的乳液。SLNs在界面上堆积地越疏松、形态上的差异越大，所形成的界面膜越厚，并且，SLNs在界面上的堆积程度受其粒径、亲水性以及颗粒之间的相互作用之间的共同影响。界面膜的厚度是影响脂肪结晶皮克林乳液稳定性及功能输送行为的主要因素，界面膜越厚，脂肪酸和活性物质的释放越少。