基于“口腔摩擦学”研究微粒化蛋白质/多糖复合物脂质口感的形成机制

The mechanism of the fat-related mouthfeel formed by microparticulated protein/polysaccharide complex based on "oral tribology".With the increasing demand for low-fat foods, the development of high-quality fat substitutes has become an important issue in food research. Microparticulated protein/polysaccharide complex is a viable fat substitute. Clarifying the mechanism of its fat-related mouthfeel and controlling its particle structure is the key to improve its fat replacement effect. Oral tribology is considered an important mechanism behind oral sensory, which is closely related to fat-related mouthfeel. The oral tribological behavior is directly affected by the structure and morphology of food particles. The project is to control of the morphology and structure of the particles, by controlling the thermodynamic parameters and molecular interactions within the particles. The surface properties of the particles, such as surface energy, hydrophilicity, functional groups will be analyzed to evaluate the adhesion effect between particles and friction surfaces, as well as between the particles, and understand the formation mechanism of the lubricating film. The friction curve and the transition of its lubrication state of the particles will be further analyzed. Finally, by analyzing the relationship between morphology, surface properties and tribological properties, as well as sensory evaluation, the mechanism of fat-related mouthfeel formed by the particles can be elucidated, and the relationship between particle morphology and fat-related mouthfeel ca be established. This project will provide important data for the precise control of the fat-related mouthfeel of the particles and provide a theoretical basis for developing high quality fat substitutes.

随着消费者对低脂食品的需求日益强烈，优质脂肪替代物的开发成为食品研发中一项重要课题。微粒化蛋白质/多糖复合物作为一种可行的脂肪替代物，明确其脂质口感的形成机制，调控其颗粒结构，是改善其脂肪替代效果的关键。口腔摩擦是口腔感官的重要机理，直接影响食物的脂质口感。因而本项目将以口腔摩擦为依据，以颗粒组装热力学、动力学及分子间相互作用为手段，调控颗粒的组成、结构和形貌特征，通过表征颗粒表面能、亲疏水性、功能基团等表面性质，明确颗粒与摩擦表面、颗粒与颗粒之间的黏附作用及润滑膜的形成模式，分析摩擦曲线与颗粒润滑状态的转化关系；并结合口腔感官评价，最终得出颗粒形貌结构、表面性质和摩擦特性之间的关联，阐明颗粒脂质口感的形成机制，建立颗粒形貌结构与脂质口感之间的关系。本项目将为精准调控颗粒的脂质口感提供重要数据，为开发优质脂肪替代物提供理论基础。

脂肪是构成食品的重要成分，过量的脂肪摄入会导致肥胖的发生，并引发心血管疾病和其它慢性疾病，但脂肪的缺失会严重影响食品的口感，使得消费者对其的接受度降低。因此，能够模拟脂肪口感的脂肪替代物的开发成为现代食品领域的重要课题。蛋白质和离子型多糖可以在静电力的驱动下形成具有“核壳”结构的复合颗粒，可用作脂肪替代物。目前对于复合颗粒脂肪替代效果的研究主要集中在感官评价，对其脂质口感形成的机制缺乏深入探讨。乳清分离蛋白（WPI）和具有不同类型电荷的阴离子多糖黄原胶（XG）、阳离子多糖壳聚糖（CS）作为基础原料制备复合颗粒，探究了影响复合颗粒形成的因素、复合颗粒的形貌特性及口腔摩擦行为，分析了其脂质口感形成的机制。研究结果证明75 ℃热处理的WPI/CS复合体系能形成以WPI为核、CS为壳，具有“核壳”结构的复合颗粒，95 ℃热处理的WPI/CS复合体系能形成“核壳”结构残缺的复合颗粒。在夹带速度小于20 mm/s的范围内，复合颗粒在水相中能产生类似“滚珠轴承”的润滑效果，同时多糖的聚合物刷效应有效的降低了边界摩擦系数，其中蛋白质含量为1%的75 ℃热处理的WPI/CS复合颗粒体系的润滑性能最好。