Antioxidant capacity in Ginkgo biloba

Abstract

The antioxidant capacity, AOC, of Ginkgo biloba nuts was determined after various periods of cooking. The AOC was based on the ability of the sample to scavenge 2,2′-azino-bis-(3-ethlybenzthiazoline-6-sulfonic acid) free radical ABTS+ . The heat-stable antioxidant components present in the nuts accounted for 60% AOC. Thus, around 40% of the AOC was lost when the nuts were cooked for 4 h. After an initial fall, related to a loss in vitamin C, the AOC remained constant. During heating, the non-ascorbic acid AOC compounds were transferred from the nuts to the leachate. A gradual formation of non-ascorbic acid antioxidants was observed in the nuts. The effect of cooking on AOC in the Ginkgo nuts was compared with Ginkgo biloba standardised leaf extracts, dried leaves extracts and Ginkgo commercial capsules.