响应面法优化红薯叶多酚超声辅助提取工艺及其抗氧化活性研究

Optimization in Ultrasonic-Assisted Extraction Process of Polyphenols from Ipomoea batatas Lam.Leaves by Response Surface Methodology and Their Antioxidant Activity

以红薯叶多酚提取率为评价指标,以提取温度、乙醇体积分数、料液比、提取时间为考察因素,在单因素实验的基础上,采用响应面法优化红薯叶多酚的超声辅助提取工艺,并通过测定红薯叶多酚对DPPH自由基、ABTS自由基的清除能力,评价其抗氧化活性。确定红薯叶多酚的最佳提取工艺为:提取温度61℃、乙醇体积分数72%、料液比1∶21(g∶mL)、提取时间33 min,在此条件下,红薯叶多酚提取率为0.9066%,与理论值0.91006%接近。红薯叶多酚具有一定的抗氧化活性,但在实验浓度范围内,其对DPPH自由基、ABTS自由基的清除率均低于VC。

Using the extraction rate of polyphenols from Ipomoea batatas Lam.leaves as an evaluation index,and extraction temperature,ethanol volume fraction,solid-liquid ratio,and extraction time as evaluation factors,we optimized the ultrasonic-assisted extraction process of polyphenols from Ipomoea batatas Lam.leaves by response surface methodologies on the basis of single-factor experiments.Moreover,we evaluated the antioxidant activity of polyphenols from Ipomoea batatas Lam.leaves by investigating their scavenging abilities against DPPH free radicals and ABTS free radicals.The optimal extraction conditions can be determined as follows:the extraction temperature of 61℃,the ethanol volume fraction of 72%,the solid-liquid ratio of 1∶21(g∶mL),and the extraction time of 33 min.Under above conditions,the extraction rate of polyphenols from Ipomoea batatas Lam.leaves can reach 0.9066%,which is close to the theoretical value of 0.91006%.Polyphenols from Ipomoea batatas Lam.leaves have certain antioxidant activity,but the scavenging rates of DPPH free radicals and ABTS free radicals by polyphenols from Ipomoea batatas Lam.leaves are lower than those by VC in the experimental concentration range.