Antioxidant activity of mung bean hulls

The antioxidant activity of methanolic extracts of mung bean hulls was investigated. Extracts at a concentration of 100 ppm exhibited stronger antioxidant activity than 100 ppm dl-alpha-tocopherol (Toe) or 100 ppm butylated hydroxyanisole on the peroxidation of linoleic acid. Moreover, a synergistic effect was observed when 100 ppm of the extract was mixed with 100 ppm Toe. Also, the extracts showed good inhibitory activity in soybean oil oxidation, which was examined by peroxide value, thiobarbituric acid, and gas chromatography of oxidized fatty acid methyl esters. The extracts can reduce the formation of both primary and secondary oxidation products of soybean oil. The extracts had reducing power and scavenged 1,1-diphenyl-2-picrylhydrazyl radical, which may in part be responsible for their antioxidant activity. Based on the results obtained, mung bean hulls are a potential source of natural antioxidants owing to their marked antioxidant activity.