离子诱导裂片石莼多糖调控多酚乳液体系的稳定机制研究

Marine algae polysaccharide, a nature non-toxic, biodegradable and high active substance, has aroused the concerns of people. Ulva fasciata belongs to marine algae, has a number of specific metabolic pathways and biological activities. Our previous study found that Ulva fasciata polysaccharide can boost immune enhancement and has good effects on in vitro antioxidance. UFP3-A, a single component of active polysaccharide with shear thickening characteristics, has been purified from Ulva fasciata and its structure is elucidated. There are many differences for stability of polyphenol emulsion induced by many ions. On this basis, this project intends to take UFP3-A as the studying molecule and explore its colloidal behavior and specificity of complexing mechanism induced by ions, with molecular parameters and experiments combination. The enzymatic degradation will be employed to prepare the active oligosaccharide fragments.The morphological character of polysaccharide and its effects of molecular weight, surface charge on stability of polyphenol emulsion are carried out. Polyphenol emissions will be analyzed by gastrointestinal digestion in vitro and rat intestinal perfusion model. The mechanism of Ulva fasciata polysaccharide induced by ions regulating stability of polyphenol emulsion is explored. Consequently, the relationship between structure, induced ions and stability of polyphenol will be established based on complexing mechanism. The results will not only provide a scientific basis on revealing the polysaccharide charateristics, but also lay the theoretical basis for the application of China’s rich seaweed polysaccharide resources in food.

海藻多糖由于天然无毒、生物降解和活性高等优点，已引起人们密切关注。裂片石莼属海洋低等藻类，具有特殊代谢途径和功能活性。前期研究发现，该多糖具有提高体外抗氧化及免疫功能；分离纯化出主链结构特征基本明确的主要多糖UFP3-A，具备剪切增稠流体特性，在不同金属离子诱导下对多酚稳定有差异。本项目拟以UFP3-A为研究对象，利用多样的分子参数和物化实验组合探讨该多糖成胶行为，明确不同离子络合机理的特异性和络合形态特征；利用控制性酶解技术，研究不同活性寡糖片段与多糖结构共性，分析对多酚乳液物化稳定及微观结构影响；利用体外模拟胃肠道消化模型(TIM)和体内大鼠肠道灌流手段动态分析多酚释放量，阐明裂片石莼多糖精细分子结构在离子诱导下调控多酚乳液稳定的分子机制，以络合机理为中介，建立多糖结构、离子诱导与多酚稳定的关联关系。该成果不仅从分子水平上理解裂片石莼多糖胶体性质，而且丰富了海藻多糖资源在食品中应用。

海藻多糖由于天然无毒、生物降解和活性高等优点，已引起人们密切关注。裂片石莼属海洋低等藻类，具有特殊代谢途径和功能活性。前期研究发现，该多糖具有提高体外抗氧化及免疫功能；分离纯化出主链结构特征基本明确的主要多糖UFP3-A，具备剪切增稠流体特性，在不同金属离子诱导下对多酚稳定有差异。本项目以UFP3-A为研究对象，利用多样的分子参数和物化实验组合探讨该多糖成胶行为，明确不同离子络合机理的特异性和络合形态特征；采用zeta-电位、动态激光散射、显微图像等分析方法，探索离子诱导对对多酚乳液物化稳定及微观结构影响。利用体外模拟口腔、胃、肠道消化和小鼠体内实验分析多酚释放量及其活性，阐明裂片石莼多糖精细分子结构在离子诱导下调控多酚乳液稳定的分子机制，以络合机理为中介，建立多糖结构、离子诱导与多酚稳定的关联关系。.结果表明，UFP多糖稀溶液表现出牛顿流体行为，在较高浓度下表现出剪切变稀的假塑性行为，特别是当多糖浓度为4% w/v时，溶液表现出反触变行为；在 0.1 Hz 到 1 Hz 频率范围，溶液的贮能模量 G′ 和损耗模量 G″ 均具有明显的频率依赖性；相同浓度的 KCl 对 UFP 凝胶强度的影响比 NaCl 大。利用UFP多糖制备出稳定乳液，并且与阿拉伯胶（GA）及甜菜果胶（BP）相比，利用UFP制备的乳液稳定性较好。单价盐离子（Na+、K+）对UFP乳液的稳定性影响不大，二价盐离子（Ca2+、Mg2+）对UFP乳液的稳定性影响十分显著，添加高浓度的Ca2+能够制备凝胶样乳液（G′＞G″），使得乳液在较大粒径和较弱的静电斥力下，仍能保持良好的稳定性。乳液的体外消化实验及其在小鼠体内抗氧化活性结果显示，UFP稳定的乳液能有效提高多酚的生物利用率，并且具有抗氧化、清除自由基、降低过氧化脂质的含量的作用。.该成果不仅从分子水平上理解裂片石莼多糖胶体性质，而且丰富了海藻多糖资源在食品中应用。