基于多糖的零反式、低饱和超分子凝胶油脂构建及稳定性机制研究

A new strategy to produce solid fats containing zero-trans and low-saturated fatty acids in order to substitute traditional fats is to produce oleogels by vegetable oil supramolecular oleogelation. At present, more researches focused on small-molecule gelators or surfactants, which are prohibited or limited by GB 2760. It is of great significance to use food-grade polymers such as polysaccharides, which have unique interface characteristics and are renewable resources to structure oil rich in unsaturated fatty acids; however, instabilities of the interface layer and oil oxidation during the preparation of the oleogel are the outstanding problems. In this project, O/W emulsion, foam system and oleogel will be produced based on the interaction of amphoteric polysaccharides, hydrophilic polysaccharides and polyphenols, respectively. The structure and interaction force of nano- and micro-liquid crystal network during the construction of oleogel will be explored, and to illuminate supramolecular self-assembly behavior of the oleogel. The effects of interface layer structure of polysaccharide-polyphenol on oxidation stability of the oleogel will be clarified. The release rule of free fatty acids and carrying nutrients in vitro digestion of the oleogel will also be evaluated. This research will reveal the internal relationship of supramolecular aggregation, structure and oxidation stability of the oleogel. The predictable and controllable technical system for structural and physical properties of the oleogel based on food-grade polymer polysaccharides and liquid unsaturated oils will be established, and will provide the theoretical basis and practical guidance for industrial customization of the functional fat products with zero-trans and low-saturated fatty acids.

植物油的超分子凝胶化是构造零反式、低饱和脂肪酸固态脂肪以替代传统脂肪的新策略，目前研究较多采用GB2760标准中禁止或限量使用的小分子凝胶因子或表面活性剂，而食品级聚合物如多糖具有独特的界面特性，为可再生资源，将其用于富含不饱和脂肪酸凝胶油脂的构建具有重要意义，但存在界面层失稳及油脂氧化的突出问题。本项目基于双亲多糖-亲水多糖、多糖-多酚的相互作用，构建含水油脂乳化体系/气泡体系及凝胶油脂，探索凝胶油脂构建过程中的纳米、微观液晶网络结构及相互作用力，阐明凝胶油脂的超分子自组装行为，明晰多糖-多酚界面层结构对油脂氧化稳定性的影响，探讨凝胶油脂体外消化过程中游离脂肪酸和载运营养素的释放规律，揭示超分子聚集方式与凝胶油脂结构及稳定性间的内在联系，建立基于食品聚合物多糖和液态不饱和油脂构建凝胶油脂结构与物性的可预测、可调控技术体系，为零反式、低饱和功能性脂肪产品的工业化定制提供理论基础和实践指导。

植物油的超分子凝胶化是构造零反式、低饱和脂肪酸固态脂肪以替代传统脂肪的新策略，食品级聚合物如多糖具有独特的界面特性，为可再生资源，将其用于富含不饱和脂肪酸凝胶油脂的构建具有重要意义，本课题基于双亲性多糖-非双亲性多糖和蛋白质-多糖的相互作用，构建了乳化体系及凝胶油脂体系，探索了聚合物基凝胶油脂的构建方法，研究发现以双亲性多糖、蛋白质作为主要的乳化剂，配合增稠多糖可制备得到凝胶强度高、网络结构紧密、持油能力好的凝胶油脂，制备得到的凝胶油脂均具有时间依赖性和结构回复行为，并且在很广的温度范围（5~80°C）内保持稳定；研究了凝胶油脂构建过程中的纳米、微观液晶网络结构及相互作用力，阐明了凝胶油脂的超分子自组装行为，探讨了聚合物基凝胶油脂的凝胶机制，发现多糖或蛋白质的分子内或分子间氢键贡献了凝胶油脂中相对有序的网络结构以将液油束缚，凝胶油脂的凝胶强度和持油能力与相应乳状液的机械强度和干物质的网络结构相关联，高浓度、相对分子量大的乳化剂能够形成更紧密的网络结构和更坚固的真空干燥物质，以及具有更高机械强度和更好持油能力的凝胶油脂；探索了生物聚合物基凝胶油脂的氧化稳定性，比较了烘箱干燥与真空干燥对于凝胶油脂的影响，贮藏过程中凝胶油脂并未发生明显的二次氧化，与烘箱干燥相比，真空干燥具有明显优势，且有利于形成更稳定的结构；探究了采用生物聚合物基凝胶油脂用于烘焙产品的制备，凝胶油脂制备得到的烘焙产品中所含饱和脂肪酸含量低，且不含反式脂肪酸，凝胶油脂烘焙产品的硬度、弹性均可达到市售起酥油和人造奶油水平，其整体可接受度与人造奶油和起酥油无显著差异。最终建立了基于食品聚合物多糖和液态不饱和油脂构建凝胶油脂结构与物性的可预测、可调控技术体系，为零反式、低饱和功能性脂肪产品的工业化定制提供理论基础和实践指导。