Antioxidant activities of five different mulberry cultivars in Korea

Five major mulberry [Pachungsipyung (M-1), Whazosipmunja (M-2), Suwonnosang (M-3), Jasan (M-4) and Mocksang (M-5)] cultivated in Korea were assessed for their polyphenolic composition using spectrophotometric methodology, and tested for antioxidant potential by some different assays. The total polyphenol (TP) was found from 2235 to 2570 μg/g gallic acid equivalents, total anthocyanin (TA) content to vary from 1229 to 2057 μg/g, coloured anthocyanins (CA) from 126 to 190 μg/g, and total flavanol (TF) from 16.4 to 65.4 μg/g catechin equivalents except Mocksang (M-5). The ethanolic extract from mulberry fruit shows a rapid and concentration-dependent increase of antioxidant activity. Especially, the antioxidant activities of M-2 and M-4 are higher than those of the others in a hemoglobin-induced linoleic acid system. The reducing power compared with BHT was observed to high value in M-2, M-3 and M-4 extracts. Effectiveness in reducing powers was in a descending order of M-4>M-2>M-3>M-1>M-1. The DPPH-scavenging ability of the ethanolic extract from mulberry fruit was 60.0% at 200 and 212 μg of M-2 and M-4, respectively. M-2 and M-4 also showed sharply increase of hydroxyl scavenging ability with concentration of the extracts. IC₅₀ values in scavenging abilities on hydroxyl radicals were 30 mg and in a descending order of M-5>M-3>M-1>M-4>M-2. Superoxide anion-sacavenging activities of M-2, M-3 and M-4 showed 17.1, 14.5 and 14.8 SOD unit/mg, respectively.