Free radical reactions with the extract of brassica family.

Using different extraction protocols, the antioxidant properties of green and red cabbage extracts were evaluated in terms of the total antioxidant capacities using the 2,2'-azino-bis(3-ethylbenzo-thiazoline-6-sulphonic acid) (ABTS) radical scavenging method. The results demonstrate that the total antioxidant capacity of green and red cabbages correlated well with the total phenolics and total flavonoids content present in the extracts. The ABTS radical scavenging capacity of red cabbage was much higher than that of green cabbage extract. Using time resolved absorption kinetic spectrophotometry, free radical reactions with the extracts of green and red cabbages were established. The reactions of extracts were examined using a pulse radiolysis technique. Kinetic studies indicated that extracts may act as free radical scavengers for O2(-), OH radicals and as an antioxidant to repair free-radical damage to biologically important guanosine radical.