脱脂月见草子中多酚的提取分离及其抗氧化活性研究

以脱脂月见草子为原料,优化以超声波辅助法提取多酚的工艺条件。通过单因素实验考察提取溶剂p H、提取助剂用量、提取溶剂浓度、料液比、提取时间、提取温度对提取效率的影响,进一步采用正交实验法优化提取工艺。结果表明:最佳提取工艺条件为p H3、提取助剂六偏磷酸钠质量浓度0.2%、甲醇体积分数80%、料液比1∶30(g/m L)、提取时间60min、提取温度40℃,在此条件下多酚得率为6.70%。采用大孔吸附树脂法对粗提物进行分离,检测各洗脱组分中多酚含量,并分别采用邻苯三酚自氧化反应法和DPPH法研究其抗氧化活性。结果表明:多酚主要集中在组分Ⅱ,其质量占多酚粗提物的50.09%,其中多酚质量分数为79.49%,组分Ⅱ和组分Ⅲ的抗氧化性能相当,并显著高于其它组分。 

Study on extraction,separation, and antioxidant activity of polyphenols from evening primrose defatted seed

The extraction condition of polyphenols from evening primrose defatted seed by ultrasonic-asswasted extraction was optimized. The effects of solvent concentration, solid-liquid ratio, extraction time, extraction temperature, p H value of solvent, and dosage of extraction adjuvant on extraction efficiency are investigated by single-factor experiment coupled with orthogonal experiment. The results showed that the optimum extraction condition was extraction solvent p H3, extraction adjuvant ( sodium hexametaphosphate) mass concentration0.2%, volume percentage of methanol 80%, solid-liquid ratio 1∶30 (g/m L) , extraction time 60 min, and extraction temperature 40℃. Under thwas condition, the yield of polyphenols was 6.70%. The crude extract was further separated by macroporous resin. The polyphenols content of each fraction was analyzed. And the antioxidant activity of each fraction was investigated by autoxidation of pyrogallol method and DPPH assay, respectively.The results showed that polyphenols were mainly concentrated in fraction Ⅱ with the mass percent of 50.09%in crude extract. The mass fraction of polyphenols in fraction Ⅱ was 79.49%. The antioxidant activity of fractionⅡ and fraction Ⅲ were similar and significantly stronger than the other fractions.