Evaluation Of Antioxidant And Study Of Stability From Xinjiang Grapevine Bleeding Sap

Objective:To compare the antioxidant capacity of Xinjiang grapevine bleeding sap(GBS) from different areas and varieties; to determine the contents of protein and saponin of Xinjiang GBS; to research the separation and purification of saponin from Xinjiang GBS; to investigate the stability methods of Xinjiang GBS antioxidant activity.Methods:1. Xinjiang GBS antioxidant activities were determined by ABTS-method, OH kit method, DPPH-method and NO2-· method.2. The protein content of Xinjiang GBS was measured by Comassie brilliant blue method.3The qualitative identification of Xinjiang GBS was done by chemical methods and TLC, and their saponin contents were determined by Vanillin-perchloric aid assay.4. Kashgar Munage GBS saponin was isolated and purfied by ultrafiltration method and macroporous resin adsorption method.5. Using·OH clearance rate and polysaccharide content as indicators, the impacts of high temperature, starch and glucose to Xinjiang GBS were studied. Results:1. There were different radical scavenging abilities in Xinjiang GBS of different varieties and areas, and the strongest was to OH. Most OH scavenging ability of Xinjiang GBS was higher than70%, which was stronger than the positive control (0.2mg/ml Vc). The order of radical clearance rate was OH>ABTS·> NO2-·>DPPH·.2Different varieties and areas had different protein contents in Xinjiang GBS. The highest was Hotan Saidbagh village red grape GBS (22.4μg/ml) and the lowest was Kashgar Munage GBS (2.96μg/ml).3. Xinjiang GBS contained certain amounts of saponin, and their saponin contents were distinct because of origins and species. Of which, Turpan Kashyyyk GBS (106μg/ml) was highest and Hotan red grape GBS (6.50μg/ml) was lowest.4. Kashgar Munage GBS saponin was separated and purified by ultrafiltration membrane whose molecular weight was1000and LSA20macroporpus resin. When the sample was loaded and eluted dynamically, the rates of loading and elution were1.5ml/min with60%ethanol as elution solvent. The OH scavenging rate (89.8%) of sample (lmg/ml) after isolated and purified was slightly stronger than the stock solution(81.0%), and there was a peak in the former by HPLC analysis.5. High temperature had no influence on the OH clearance rate of Xinjiang GBS, but the lower concentration glucose was opposite, and starch only affected the OH clearance rate of Kashgar Munage. The polysaccharide content of Xinjiang GBS was reduced to varying degrees by high temperature, starch and glucose. Conclusion: Xinjiang GBS has strong antioxidant capacity and certain contents of protein and saponin, and saponin may be one of the GBS antioxidants. Ultrafiltration combined with macroporous resin adsorption method can separate and purify GBS saponin. After isolation and purification, the ingredient has higher antioxidant ability, and its specific structural component needs further analysis. The antioxidant ability of Xinjiang GBS can be stabilized by low concentration glucose, whose exact mechanism needs further study.