超声波辅助提取紫玉兰叶多酚工艺及其抗氧化活性研究

Study on Ultrasonic-assisted Extraction of Polyphenols from Magnolia liliiflora Leaves and Its Antioxidant Activity

采用超声波辅助提取法从紫玉兰叶中提取多酚.通过单因素试验对影响紫玉兰叶多酚提取率的超声温度、超声时间、乙醇体积分数和液料比进行考察,再由单因素试验结果进行4因素3水平的响应面优化设计.通过Design-Expert 8.0.6b软件进行数据分析,以优化紫玉兰叶多酚的提取条件.结果表明,在超声温度为68℃、超声时间为35 min、乙醇体积分数为73%和液料比为22 mL/g的工艺条件下,紫玉兰叶中多酚的提取率最高.进行3组验证性试验,得出多酚的提取率为44.76 mg/g,与预测值(45.41 mg/g)的相对误差为1.43%,表明利用响应面法对紫玉兰叶多酚的提取工艺优化可靠、可行.紫玉兰叶多酚对DPPH和OH表现出较好的清除能力,当紫玉兰叶多酚质量浓度为100 mg/L时,对DPPH的清除率达到77.25%,当紫玉兰叶多酚质量浓度为250 mg/L时,对OH的清除率达到80.53%.该研究可为紫玉兰叶多酚开发成天然的自由基清除剂,提高紫玉兰的经济和应用价值提供新的方向.

Polyphenols were extracted from Magnolia liliiflora leaves by ultrasonic-assisted extraction.The ultrasonic temperature,ultrasonic time,ethanol concentration,and liquid-to-material ratio,which had an effect on extraction yield of polyphenols from Magnolia liliiflora leaves,were investigated by single factor experiment,and then a response surface optimization design with 4 factors and 3 levels was carried out based on the single factor test results.Data analysis was carried out by Design-Expert 8.0.6b software to optimize the extraction conditions of Magnolia liliiflora leaves polyphenols.The results showed that the extraction yield of polyphenols in Magnolia liliiflora leaves was the highest when the ultrasonic temperature was 68℃,the ultrasonic time was 35 min,the ethanol concentration was 73%,and the liquid-to-material ratio was 22 mL/g.Three groups of verification were performed based on the performance test,and the result showed that the extraction yield of polyphenols was 44.76 mg/g,and the relative error from the predicted value(45.41 mg/g)was 1.43%,indicating that the optimization of the extraction process of polyphenols from Magnolia liliiflora leaves by response surface method is reliable and feasible.Magnolia liliiflora leaves polyphenols showed good scavenging ability to DPPH and OH.When the concentration of Magnolia liliiflora leaves polyphenols was 100 mg/L,the clearance rate of DPPH reached 77.25%.When the concentration of Magnolia liliiflora leaves polyphenols was 250 mg/L,the removal rate of OH reached 80.53%.This research can provide a new direction for the development of Magnolia liliiflora leaves polyphenols into natural free radical scavengers and improve the economic and application value of Magnolia liliiflora.