Optimization of Polyphenols Extraction from Phyllanthus emblica L. Pomace and Its Antioxidant Activity Analysis

The remaining Phyllanthus emblica pomace after juicing contains a large amount of polyphenols. In order to further improve the resources utilization of Phyllanthus emblica,the extraction process of polyphenols from Phyllanthus emblica pomace was optimized for increased extaction amount of polyphenols. The influence of ethanol volume fraction,temperature,extraction time and ratio of material to solvent on extraction efficiency was investigated initially by single-factor test. On the basis of the single-factor test,the Box-Behnken response surface methodology was used to optimize the extraction technology,mathematical model was established by implementing three factors and three levels. The optimum technological conditions were extraction temperature of 60 ℃,ethanol volume fraction of 60%,extraction time of 80 min,ratio of material to solvent of 1:33 g/mL. Under these optimized conditions,the average extaction amount of polyphenols was 126.25 mg/g,the relative standard deviation was 0.59% compare with the predicted value. The antioxidant activity of extractive was evaluated by oxygen radical absorbance capacity(ORAC),ferric ion reducing antioxidant power(FRAP),ABTS and β-carotene bleaching test. The ORAC and FRAP of extractive was more than 50% and 40% of V_C respectively. The IC₅₀ of ABTS of extractive was less than that of V_C and Trolox significantly. The IC₅₀ of β-carotene bleaching of extractive was less than 2 times of BHT,and was significant less than Trolox.The result indicated the extractive had high antioxidant activity. The results of this study provide a test basis for further research and application of polyphenols in Phyllanthus emblica.