香蓼总多酚超声波辅助提取工艺优化及其体外抗氧化活性评价

优化香蓼总多酚提取工艺,探讨总多酚的抗氧化活性。以超声波辅助提取方法,乙醇体积分数、料液比和提取时间为因素,采用正交实验,对香蓼总多酚提取工艺进行优化,得到优化香蓼总多酚的提取条件:提取温度30℃、乙醇体积分数50%、料液比1∶50和超声25 min,提取2次,香蓼总多酚的含量为（94.6±0.15）mg/g,平均回收率为100.07%,变异系数为1.00%（n=5）。并通过1,1-二苯-2-苦基肼自由基（DPPH·）清除率和总抗氧化活性的测定对香蓼总多酚进行体外抗氧化活性评价,结果显示:香蓼总多酚的总抗氧化活性和DPPH·清除率均明显高于特丁基对苯二酚（TBHQ）,且香蓼总多酚DPPH·半数抑制浓度（EC50=5.5μg/m L）优于TBHQ（EC50=18.0μg/m L）。香蓼总多酚是一种天然的抗氧化活性剂和自由基清除剂。 

Optimization of ultrasonic assisted extraction technology of total polyphenol from Polygonum viscosum and its antioxidant activity evaluation in vitro

The extract process of total polyphenol from Polygonum viscosum was optimized and the antioxidant activity of total polyphenol in vitro was evaluated.Ethanol concentration, solid to liquid ratio, and extrction time were chosen as the independent variables using ultrasonic-assisted extration method.The optimum technological parameters of ultrasonic-assisted extraction for total polyphenol from P. viscosum were studied via the orthogonal experiment. Finally, the optimal extraction conditions were obtained: extraction temperature 30 ℃, ethanol concentration was 50% ( v/v) , the ratio of solid to liquid was 1 ∶ 50, ultrasonic time was 25 min, and extraction times were 2 times. It was found that the total polyphenols content from the P. viscosum was ( 94.6 ± 0.15) mg/g, average recovery rate of total polyphenol was 100.07%, variation coefficient was 1.00% ( n = 5) .The antioxidant activity was determined though 1, 1-Dipheny l-2-picrylhydrazyl free radical ( DPPH·) scavenging rate and total antioxidant activity test.The results indicated that the antioxidant activity of total polyphenol in P. viscosum was stronger than that in tertiary butylhydroquinone ( TBHQ) , and the EC50value ( 5.5 μg/m L) of DPPH· scavenging rate from P.viscosum was better than the EC50value ( 18.0 μg/m L) of TBHQ. Total polyphenol in P. viscosum is a natural antioxidant and free radical scavenger.