湄潭白茶多糖抗氧化活性及稳定性研究

Antioxidant Activity and Stability of Polysaccharides from Meitan White Tea

目的:探讨不同条件对湄潭白茶多糖抗氧化活性及稳定性的影响。方法:采用体外检测法评价湄潭白茶多糖的抗氧化活性,同时以清除DPPH自由基能力为指标,考察温度、pH值、紫外线、食品添加剂及金属离子等对其稳定性的影响。结果:湄潭白茶多糖具有一定的抗氧化作用,对DPPH·和·OH具有较好的清除能力;随着温度的升高,湄潭白茶多糖的抗氧化活性逐步降低;随紫外线照射时间的延长,湄潭白茶多糖对DPPH·清除率小幅度降低,而pH值的变化对湄潭白茶多糖DPPH·清除率具有较大影响;葡萄糖或蔗糖等食品添加剂对湄潭白茶多糖稳定性的影响较小,而柠檬酸钠和大多数金属离子会对其抗氧化活性及稳定性产生影响。结论:湄潭白茶多糖具有较好的体外抗氧化活性,其相关产品的加工、储存及运输应避免高温及与柠檬酸钠、金属离子等物质直接接触。

Objective:To investigate the effect of different conditions on antioxidant activity and stability of polysaccharides from Meitan white tea.Methods:The in vitro detection method was used to analyze the antioxidant activity of polysaccharides from Meitan white tea,and the DPPH free radical scavenging ability as the research object,the effect of factors such as temperature,pH,ultraviolet rays,food additives and metal ions on the stability of polysaccharides was investigated.Results:The polysaccharides from Meitan white tea had certain antioxidant activity,it has good scavenging ability of the DPPH free radical and hydroxyl radical.With the increase of temperature,the antioxidant activity of polysaccharides gradually decreased.With the increase of the ultraviolet rays time,the DPPH clearance of polysaccharides decreased slightly.The change of pH had influence on the DPPH clearance of polysaccharides.Food additives such as glucose or sucrose had little effect on the stability of polysaccharide,while sodium citrate and most metal ions had effect on its antioxidant activity and stability.Conclusion:The polysaccharides from Meitan white tea had good antioxidant activity in vitro,its should be processed,stored or transported to avoid high temperature and direct contact with sodium citrate and metal ions.