中文摘要：

基于单因素试验结果,利用响应面法（RSM）优化天麻多糖的超声波提取工艺,依据回归分析确定多糖提取率的影响因子,求得最佳浸提条件为：水料比40∶1,超声波输出功率75.70%,超声时间29.32min。采用分光光度法和化学发光法比较天麻多糖与3种天然抗氧化剂α-硫辛酸、Vc和VE对二苯代苦味肼基自由基（DPPH·）、超氧阴离子自由基（O2-·）、羟自由基（·OH）、过氧化氢（H2O2）以及过氧亚硝基阴离子（ONOO-）的清除能力。结果表明,在0~500μg/m L质量浓度范围内,天麻多糖对DPPH·的清除率和α-硫辛酸的清除效果接近,强于VE,明显弱于Vc,最高清除率达到22.37%;对O2-·的清除能力强于Vc和VE,弱于α-硫辛酸,最高清除率达到12.23%;对·OH的清除能力弱于Vc,在400~500μg/m L质量浓度范围内清除率与α-硫辛酸、VE接近,最高清除率达到4.85%;对H2O2的清除能力强于α-硫辛酸,略弱于VE,明显弱于Vc,最高清除率达到25.80%;对ONOO-的清除能力明显弱于α-硫辛酸和Vc,最高清除率达到20.52%。

英文摘要：

Response surface methodology（RSM）was applied to optimize the extraction conditions for polysaccharides from Gastrodia elata based on single factor tests. Technological condition parameters were determined according to regression analysis. The optimum conditions were as follows ：ratio of water to material was 40 ：1,ultrasonic power output was 75.70%,extraction time was 29.32 min. Spectrophotometry and chemiluminescence were employed to compare the abilities of scavenging free radicals including DPPH·,O2-·,·OH,H2O2 and ONOO- of polysaccharides extracted from G. elata and three natural antioxidants α-lipoic acid,Vc and VE. The results showed that at the concentration of 0-500 μg/m L,the scavenging ability of polysaccharides extracted from G. elata on DPPH· was similar to that of α-lipoic acid,stronger than that of VE,obviously weaker than that of Vc,the highest clearance rate reached 12.23%;the scavenging ability on ·OH was weaker than that of Vc,similar to that of α-lipoic acid and VE at the concentration of 400-500 μg/m L,the highest clearance rate reached 4.85%;the scavenging ability on H2O2 was stronger than that of α-lipoic acid,slightly weaker than that of VE,obviously weaker than that of Vc,the highest clearance rate reached 25.80%;the scavenging ability on ONOO- was obviously weaker than that of Vc and α-lipoic acid,the highest clearance rate reached 20.52%.