山茱萸美拉德反应产物的超滤分离及其体外抗氧化活性

目的:通过超滤分离中药山茱萸美拉德反应产物的最佳有效部位,并比较各截留产物的理化性质和体外抗氧化作用。方法:以山茱萸为美拉德反应底物,经高温反应后获得反应产物。采用中空纤维膜对反应产物进行分级过滤,过膜级数为0.45、0.22μm、100、50、10、4 ku,对各分级截留产物分别进行冷冻干燥并测定它们的理化特性(紫外吸收和褐变程度);同时观察它们对DPPH自由基的清除能力和对铁氰化钾的还原能力。结果:不同截留产物的紫外吸收曲线基本类同,且在284 nm处均有最大吸收。相比之下,0.45~0.22μm截留产物的褐变程度最大,同时其自由基清除率和还原能力也最高。结论:提示山茱萸美拉德反应产物中抗氧化的最佳活性部位为0.45~0.22μm的超大分子类物质。 

Ultrafiltration separation of Maillard reaction products of Fructus corni and their antioxidant activity

Objective: To separate the best active fraction of Maillard reaction products( MRPs) of Fructus corni by ultrafiltration and compare the properties and antioxidant activities of different molecular weight cutoffs of Fructus corni MRPs.Methods: Fructus corni was adopted as substrate for Maillard reaction and MRPs were obtained after reactions at high temperature.The MRPs were ultrafiltered by hollow fiber membrane of 0.45 μm,0.22 μm,100 ku,50 ku,10 ku,4 ku,and then lyophilized to get different molecular weight cutoffs of Fructus corni MRPs.Physical and chemical properties of different molecular weight cutoffs were determined,and the radical scavenging ability on DPPH radical and the reducing ability of potassium ferricyanide were also observed. Results: The UV absorption curves of different molecular weight cutoffs were similar and the maximum absorption was all at 284 nm. Among different molecular weight cutoffs of Fructus corni MRPs,cutoffs of 0.45~0.22 μm had the highest browning degree and strongest scavenging ability on DPPH radical and reducing ability of potassium ferricyanide. Conclusion: It suggests that the best antioxidant active fraction of Fructus corni MRPs are super- macromolecules with size of0.45~0.22 μm.