为了增强莲藕多糖的功能特性和绿原酸的稳态化利用，该研究考察了莲藕多糖与绿原酸的非共价相互作用，探究了两者复合物的理化性质、稳定性和生物活性。通过单因素和响应面试验，以绿原酸结合率为指标确定最佳制备工艺为：温度0 ℃，pH值为5.5，多酚与多糖质量比4:1。在此工艺条件下，莲藕多糖与绿原酸的结合率为2 174.01 mg/g，其平均分子量由146.3 ku增加到162.1 ku。红外光谱和紫外光谱特征证明了莲藕多糖和绿原酸非共价结合的存在。该复合物的解离率与温度呈正相关，低温有利于维持复合物的稳定，而经口腔、胃或小肠模拟消化后的解离率均低于25%。该复合物对DPPH自由基清除率呈浓度依赖性，具有一定的抗氧化能力。该复合物可显著诱导RAW264.7细胞产生NO的同时，也能明显抑制LPS诱导RAW267.4细胞产生NO，即同时具有免疫激活和免疫抑制的能力。该研究为莲藕多糖和绿原酸的加工利用提供一定的理论支持。

To enhance the functionality of lotus root polysaccharides (LRPs) and stabilize chlorogenic acid (CHA) while also facilitating its use, the noncovalent LRP and CHA interactions were studied alongside the physicochemical properties, stability, and bioactivity of the LRP-CHA complex. Based on single-factor and response surface design experiments, the optimal parameters for the preparation of LRP-CHA complexes (measured by CHA binding to LRP) were a temperature of 0 ℃, pH of 5.5, and polyphenol-to-polysaccharide mass ratio of 4:1. These parameters yielded a CHA-to-LRP binding rate of 2 174.01 mg/g and an increase in the average molecular weight from 146.3 ku to 162.1 ku. The IR and UV data indicate noncovalent binding between LRP and CHA. As the dissociation rate of the LRP-CHA complex was found to be positively correlated with temperature, low temperatures are assumed to maintain the stability of the complex. Nonetheless, the dissociation rate was generally less than 25% following simulated oral cavity, stomach, or intestine digestion. The LRP-CHA complex shows dose-dependent scavenging activity for DPPH free radicals, which is indicative of antioxidant activity. Furthermore, the LRP-CHA complex significantly induces NO production in RAW264.7 cells, while also suppressing LPS-stimulated NO production, indicating that it possesses both immunoactivatory and immunosuppressive effects. The findings of this work are expected to serve as theoretical support for the processing and utilization of LRP and CHA.

湖北省重点研发计划项目（2021BED006）；湖北省青年拔尖人才培养计划项目；武汉市知识创新专项基础研究项目（2022020801010389）