微波预处理-溶剂回流提取马占相思叶多酚的工艺研究

研究微波预处理-溶剂回流提取马占相思叶多酚的工艺条件。以干马占相思叶粉为原料,用正交实验法对马占相思叶总多酚的微波预处理提取工艺进行优选,考察预处理乙醇浓度、固液比、微波处理时间对马占相思叶总多酚提取量的影响。结果表明,微波预处理溶剂回流提取马占相思树叶总多酚的最佳工艺参数为:润湿乙醇浓度为50%,用量为样品量的2倍,在微波功率800 W条件下处理30 s后,用体积分数70%乙醇在料液比1∶7,水浴温度70℃、自然pH值(pH=6.38)浸提条件下回流提取30 min。在此工艺条件下,可提取总多酚18.013 mg/g马占相思树叶,所得的多酚提取物以总多酚计的清除DPPH自由基的IC50值为39.126 g DPPH/g总多酚。

Study on extraction of total polyphenols from Acacica mangium leaves by microwave pretreatment

The process of extracting polyphenols from Acacica mangium leaves by microwave pretreatment was studied systematically.The dried leaves were used as the crude drug,the effect of the operation parameters during the extraction on the extraction result was analyzed with monofactor experiment and the optimum extraction process was optimized with orthogonal test.Experiments were made by using L9(34) orthogonal design with extractive yield of total polyphenols as the index,investigating the influence of ethanol concentration,the ratio of solid to liquid,microwave pretreatment time.Results showed that optimum extraction conditions were determined as follows:microwave pretreatment ethanol concentration 50%,the ratio of solid to liquid 1 ∶2(g/mL,mass:volume),microwave pretreatment time 30 s,extreating temperature 70 ℃,time 30 min,70% EtOH as extracting solvent,natural pH value(pH=6.38),stock ratio 1 ∶7.The extractive yield of total polyphenols from Acacica mangium leaves was 18.013 mg/g and IC50 of scavenging DPPH free radicals of total polyphenols was 39.126 at the optimum parameters.