玉米须抗氧化物质乙醇提取工艺及清除自由基活性

The Extraction Technology by Ethanol and Free Radical Scavenging Activity of Antioxidants from Stigma maydis

以提取率为指标,运用单因素试验和响应面优化方法,研究玉米须中抗氧化物质的乙醇提取工艺。考察液料比、提取温度、提取时间、提取次数和乙醇体积分数的影响。结果表明,对提取率影响较大的因素是液料比、提取次数和乙醇体积分数,确定最佳提取工艺,即提取溶剂采用80%乙醇,液料比24∶1 mL/g,在60℃下提取90 min,共提取3次。采用该工艺,玉米须中抗氧化物质的提取率为3.72%。考察不同提取率的玉米须抗氧化物质对DPPH自由基和羟自由基的清除活性。结果显示,乙醇提取的玉米须抗氧化物质可以清除2种自由基,并且其提取率升高不影响对自由基的清除活性。

Single factor experiment and response surface methodology were used to study the ethanol extraction process of antioxidants from Stigma maydis.The influence of the liquid-to-material ratio,extraction temperature,extraction time,the times of extraction and ethanol concentration on the extraction rate were studied.It was found that the liquid-to-material ratio,the times of extraction and ethanol concentration had great influence on the extraction rate.The results showed that the best condition was 80%ethanol,liquid-to-material of 40∶1 mL/g,extraction time of 90 min and extracting for 3 times.Under this condition,the extraction rate of antioxidants was 3.72%.The scavenging activities of antioxidants from Stigma maydis with different extraction rates to DPPH and hydroxyl radicals were investigated.The results showed that it could significant scavenge DPPH and hydroxyl radicals,and the improvement of extraction rate had no significant influence on scavenging activities.