植物多酚-溶致液晶有序复合体的构筑规律及其性能调控

The poor stability, poor physic-chemical properties and the low bioavailability of plant polyphenols became a crucial factor to stop these natural antioxidants entering the functional foods, and play a role as an antioxidant. To this end, financed by a one-year pre-research project of NSFC in 2011, we have successfully screened the biocompatible surfactant systems and constructed lyotropic liquid crystals (LLCs) with different structure. Moreover, the impacts on structure and properties of the LLC systems by a variety of factors have been studied. In this proposal, taking the bio-compatible LLCs as the carrier, three different type of plant polyphenol compounds including curcumin, apigenin and catechin (EGCG) as the target factors, firstly, to investigate the construction, the properties and phase transition of the plant polyphenol-LLC complexes by using the pseudoternary phase diagram, SAXS, mesoscopic simulation and the rheological measurement. After that, to investigate the effects of liquid crystal structure, temperature, pH and other factors on the solubilization of the target polyhenol, the encapsulation stability and the release behaviour. Then, to research the antioxidant property and the synergism of the polyphenols in the LLC heterogeneous systems. At last, to reveal the regular pattern of solubilization and release of the target factor in the ordered complexes. Furthermore to establish the method that can predict the relationship between the structure of LLC and the performance of the target polyphenol.

解决植物多酚的稳定性差、理化性能差、口服生物利用度低的问题，是这类天然抗氧化剂进入功能食品配方并有效发挥其抗氧化活性的关键因素。为此，在基金委资助2011一年期预研项目中，我们成功筛选了生物相容表面活性剂体系并构筑了不同结构的溶致液晶，研究了多种因素对溶致液晶结构和性质的影响。本课题以生物相容溶致液晶作载体，选择3个结构类型不同的植物多酚化合物姜黄素、芹菜素、儿茶素(EGCG) 为目标因子，首先应用拟三元相图、介观模拟、SAXS、流变学测量等手段，研究目标植物多酚-生物相容溶致液晶有序复合体的构筑和性质及其相转变。在此基础上进一步研究液晶结构、温度、pH等因素对目标因子包封、包封稳定性及其释放的影响。研究目标因子在溶致液晶多相体系中的抗氧化作用及其协同效应。揭示目标因子在液晶中包封和释放的规律，初步建立预测载体液晶的结构对目标因子性能影响规律的方法。

植物多酚的生物利用度低是限制其进入功能食品发挥其抗氧化活性的主要因素，提高植物多酚生物利用度的关键是改善其溶解性、稳定性等理化性能。在前期的工作中我们成功筛选了生物相容表面活性剂体系构筑溶致液晶，研究了多种因素对溶致液晶结构和性质的影响，本项目将成果进一步扩展以姜黄素、芹菜素、二氢杨梅素、茶多酚为研究对象，以溶致液晶、微乳液为载体，借助胶体化学、流体力学、溶液化学和理论计算等手段有目的地构筑了包封姜黄素、芹菜素、二氢杨梅素的层状、六角和立方液晶及包封姜黄素、芹菜素、茶多酚的O/W和W/O微乳液，利用SAXS、流变技术、D-NMR、Hot Stage POM、PXRD、H-NMR、DSC、FT-IR、DLS等现代技术手段，从体系的微观结构、热稳定性、粘弹性质等方面继续深入研究了有序聚集体相结构演变的条件、探讨相转变的驱动力，探讨了液晶结构、温度、pH等因素影响目标因子包封稳定性和释放的规律及释放动力学，建立了植物多酚/溶致液晶复合体流变参数tanδ 与累计释放率的关系，采用微乳液包载和溶致液晶水相分散颗粒两种方法对植物多酚的抗氧化活性进行了追踪，提出了自由基“清除效能”和“清除效率”两个参数以全面表征体系的抗氧化能力，此外，结合实验利用分子动力学和MesoDyn介观动力学等现代计算模拟手段探索从微观和介观尺度上预测分析聚集体的聚集及相变的过程。