纤维素纳米晶对多酚抗氧化稳定性的增强效果及其作用机制的研究

As a natural antioxidant, polyphenols have multiple health benefits, such as disease treatment, aging-resistance, etc., and are popular-used in various industries. However, the application of polyphenols is often limited due to their poor stability during storage and processing. In order to improve the stability of polyphenols, cellulose nanocrystal (CNC) was used as carrier to well-load the polyphenols particles in the form of nanocomposite. The mechanism for the adsorption of polyphenols by CNC was well investigated by the thermodynamics stimulation and “analog deduction” method. Meanwhile, the targeted release of polyphenols in the Gastrointestinal Tract was studied by vitro digestion simulation experiment, thus characterizing the vivo antioxidant efficiency of polyphenols after being carried by CNC. This would allow CNC to be used as an innovative natural nano-based material for enhancing the stability of polyphenols. Also, the mechanism for the CNC loading polyphenols was well presented which would be beneficial for extending the potential to apply CNC as carriers for more hydrophilic/ hydrophobic molecules.

多酚作为天然抗氧化剂中的一种，具有优异的祛病、防老的保健功效，而深受各类行业的欢迎。但由于其在贮存和加工过程中存在着较为严重的不稳定性，从而在很大程度上限制了它的应用规模。本项目即针对多酚类抗氧化剂的稳定性差的问题，以纤维素纳米晶（CNC）作为基材，来增强多酚复合物的抗氧化稳定性；通过构建“负载”型纳米复合模型物的形式，采用吸附热力学方程拟合和“类比验证法”，阐明CNC与多酚粒子之间的吸附作用机制；进行“体外模拟消化实验”，考察复合物在人体胃肠部位的靶向释放效果，以研究CNC的负载对多酚体内缓释率的影响。本项目的成功实施不仅有利于突破对于复合基材的传统性选择的束缚，为多酚稳定性的提高提供一种全新的功能性纳米载体，同时也将从机理方面深入探讨CNC对多酚颗粒的负载机制和作用规律，为CNC对更多亲水性/疏水性小分子的负载奠定理论基础。

本项目主要针对天然多酚类抗氧化剂的稳定性差的问题，采用纤维素纳米晶（CNC）作为基材制备得到了一种具备高抗氧化稳定性的多酚纳米复合物。高效液相色谱（HPLC）和DPPH自由基清除率的检测结果证实了该多酚复合物在不同贮存条件下的物理稳定性及抗氧化持久性。通过Langmuir等温线方程及Freundlich等温线方程热力学模型拟合，并结合电荷置换和氢键屏蔽等研究手段，揭示了CNC与多酚之间的吸附机制。CNC-多酚纳米复合物的体外模拟消化实验拟合了多酚在体内胃肠道中的动力学脱吸附行为。此外，作为本项目的衍生产品，CNC-多酚复合物作为活性成分在功能性复合膜和抑菌性乳液领域中的技术应用和转化也进行了一系列尝试，分别制备得到一种高平滑且对气体具备智能选择透过性的高密度膜，和一类具备高抑菌效率的水基抑菌乳液。本项目的成功实施为多酚性能的改善提供了一种全新的功能性纳米载体，而CNC与多酚颗粒之间结合机制的探讨也为CNC对其他类别的高活性小分子的负载奠定了理论基础。