苦苣多酚超声辅助提取及抗氧化研究

Study on ultrasound-assisted extraction and antioxidant activity of phenolics fromsonchus oleraceus L.

优化超声波辅助提取苦苣中多酚的工艺条件,并研究其抗氧化活性。试验结果表明,苦苣中的多酚提取条件为:乙醇浓度70%、液固比30∶1(V∶m)、超声波功率2 55W、超声20min、浸提温度75℃和浸提时间2h;该条件下提取率1.040%。苦苣多酚的还原能力与其浓度成正相关性,在低于0.15mg/mL时还原力比VC弱,高于0.15mg/mL时还原力与VC相当;苦苣多酚对DPPH清除率随浓度的提高而增大,但增大幅度逐渐减小;在含量相同的情况下,苦苣多酚的自由基清除能力与Vc相当。试验证明:苦苣多酚是一个潜在的天然安全有效抗氧化剂。

To study the technical process and suitable conditions for extraction of polyphenol from Sonchus oleraceus L. by ultrasonic technology and mensurating its antioxidant activity. Folin - Ciocal teu reagent colorimetry method was used to determine total polyphe- nols from Sonchus oleraceus L. By using DPPH, · OH and potassi um ferricyanide reduction method to investigate the comparison of the ability of antioxidant of phenolics of sonchus oleraceus L. and Vc. The extraction conditions were as followed： 70% ethanol solution, liquid-solid ratio 30 ： 1（V ： m）, ultrasonic power 255 W, ultrasonic time 20 min ,extraction temperature 75 ℃, extraction time 2 h, and the average extraction yield of phenolics from Sonchus oleraceus L. was 1. 040%. The reducibility of polyphenol in Sonchus oleraceus L. has high correlation with the concentration. When the concentration is lower than 0. 15 mg/mL, the reducing force is weaker than Vc, but if higher .than 0.15 mg/mL, the reduce force is the same as Vc. And as the higher density is, the higher removal rate on DPPH. At the same concentration, Sonchus oleraceus L. polyphenol behaved the best antioxidant activity, which was similar to Vc. It is a potential natural product waiting to be developed.