Study on Antioxidant Activity of Pigment in Black Soybean Peel

With black soybean as raw materials, 50% ethanol as the extractant, at 70°C, pH1.0, solid-liquid ratio of 1:100(g:mL), at 90min were used to extract the pigment of black soybean Through the establishment of DPPH•,•OH, superoxide anion free radicals, reducing power and hydrogen peroxide. The results show: its ability of scavenging DPPH•, •OH, hydrogen peroxide is far better than ascorbic acid. The pigment at concentration of 0.6mg/mL shows a scavenging rate for DPPH• up to 88.29%,and for •OH 89.36%,for hydrogen peroxide89.75%.In addition，the general reducing power and scavenging rate for superoxide anion solution of the pigment are a little worse than those of ascorbic acid.