Dietary phenolics and antioxidant capacity of selected legumes seeds from the central Balkans

Abstract

The aim of this study was to select Vicia genotypes with higher polyphenol contents and increased antioxidant activity, and to compare them with soybean, the most widespread and utilized legume species grown in the region. The examined legumes showed similar contents of total polyphenolics and tannins in between specimen, but differed greatly in their flavonoids and proanthocynidins levels. The content of total polyphenols ranged from 1.6 to 6.09 catechin/g dry seeds, and tannins from 0.26 to 2.98 mg of catechin/g dry seeds. The flavonoids levels in Vicia species were much higher compared with soybean, while the content of proanthocyanidins ranged from 1.5 (in soybean) to 62.3 mg of leucoanthocyanidin/g dry seeds (in vetches). The gallic and trans-cinnamic acids were identified as major monomeric phenolic compounds, and quercetin among flavonoids was found in all specimens. Catechin was detected in faba bean and vetches but not in the soybean. The values of the DPPH-test varied in a range between 21.1 and 89.6% of neutralized radicals, which correlated with the total polyphenolics and tannin contents. The faba bean specimens showed favourable traits - high total polyphenolic, flavonoid and proanthocyanidin contents, low total tannin content, and high DPPH-radical scavenging ability.