Antioxidant capacity and content of Brassica oleracea dietary antioxidants

This study has evaluated the antioxidant capacity and content of both water- and lipid-soluble antioxidants present in red and white cabbages, savoy cabbage and Brussels sprouts. Total phenolic and vitamin C contents varied from 21 to 171 mg per 100 g and from 18 to 129 mg per 100 g, respectively. Levels of carotenoids ranged from 0.009 to 1.16 mg per 100 g, while alpha-tocopherol levels from 0.008 to 0.82 mg per 100 g. Red cabbage and Brussels sprouts were the most rich sources of dietary antioxidants, while their content was the lowest in white cabbage. Water-soluble antioxidants were the main antioxidant compounds in the vegetables tested, and their contribution to the trolox equivalent antioxidant capacity values was near 99%. Among phenolic compounds, anthocyanins were the main constituents in red cabbage, but hydroxycinnamic acids predominated in other vegetables. Phenolic extracts were capable of scavenging O-2(.-), DPPH. and ABTS(.+) radicals and inhibited a lipid peroxidation in a linoleic acid emulsion.