Extraction and antioxidant activity of polyphenols from black peanut coat

An investigation into solvent extraction was conducted for the anthocyanins and total polyphenols extraction from black peanut coat. The best possible combination of extraction parameters was obtained with the response surface methodology (RSM) , at a three-variable, three-level experiment Box-Behnken design (BBD) . The optimum extraction parameters were as follows:extraction time 120min, extraction temperature 40℃ and sample/solvent ratio 1 ∶60 , at a fixed ethanol concentration of 60% . Under these conditions , the anthocyanins recovery and the total polyphenols were 6.013 , 47.892mg/g, respectively. The antioxidative activities of extract of black peanut coat, which was purified by macroporous resin, were investigated employing various established in vitro systems including 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radicals scavenging and reducing power. The result revealed that the extract had strong antioxidant activities which were correlated with its high level of phenolics. The extract can be used as a source of potential antioxidant or functional food colorant.