皂苷（Saponin）作为广泛存在于天然植物界中的一大类糖苷近年来受到广泛关注。在分子结构上，天然皂苷是以三萜或甾体苷元的疏水基为支架并附着亲水性糖链所构成，从而表现出高界面活性。天然皂苷分子结构的多样性不仅使其具有生物活性和独特的物理化性质，促进其在食品、化妆品以及其他领域中的广泛应用。本研究结合近年来对天然皂苷结构特性、自组装和界面特性的研究，试图探究皂苷结构如何影响其在水相、气-水界面、油-水界面和固-液界面的组装行为，以及其对食品胶体功能特性的影响。自组装和界面结构可能因植物来源和分子结构而不同：具有三萜结构的皂苷最有助于形成粘弹性界面膜，产生稳定的食品胶体；而甾烷类皂苷更倾向于具有特殊的生理活性。其中天然皂皮皂苷表现最为优异，已被证实可形成稳定的胶束、纳米乳液、乳液凝胶和泡沫等用于生物活性物质的输送，目前已被包括中国、美国和欧盟等多数国家批准用于食品。

As a large class of glycosides, saponins are widely distributed in natural plant kingdom, has received extensive attention in recent years. In terms of molecular structure, natural saponins are composed of hydrophobic aglycone backbones of triterpenoids or steroidal glycosides (hydrophobic scaffolds) attached with hydrophilic sugar chains, resulting in a high surface activity. The structural diversity of natural saponins not only makes them possessing biological activity and unique physicochemical properties, but also promotes a wide range of applications in foods, cosmetics and other fields. Based on the recent research on the structural characteristics, self-assembly and interface properties of natural saponins, this study attempts to explore the effect of the structure on the assembly behavior at aqueous phase, and air-water interfaces, oil-water interfaces and solid-liquid interfaces, and on the functional characteristics of food colloids. Moreover, the self-assembly and interfacial structures may vary with the plant source and molecular structure: Saponins with a triterpenoid structure most likely form viscoelastic interfacial membranes, resulting in stable food colloids; while saponins with a steroid structure tend to possess special physiological activities. Among them, natural Quillaja saponins perform at their best. They have been proven capable of forming stable micelles, nanoemulsions, emulsion gels and foams for the delivery of bioactive substances, and gained approval for food applications in most ocountries such as China, the United States and the European Union.

国家自然科学基金资助项目（31801461）；广东省天然产物绿色加工与产品安全重点实验室开放基金（KL-2018-09）；河南工业大学高层次人才科研启动基金（2018BS083）