Antioxidant Activities of Some Vegetable Foods and Active Component of Avocado Epicarp

Abstract

Antioxidant activities in the methanol soluble fraction of the rind and the content of 12 kinds of fruits, 37 vegetables and 7 others, were examined by the inhibitory effect on the formation of the peroxide from methyl linolate in the test tube at 50°C. Among these samples the epicarp of avocado showed the strong antioxidant activity. It corresponds to about one third of the activity of green tea, rosemary or sage which are already reported with their strong antioxidant activities. Besides, the activity was observed in the followings: a flower of the butter bur, yellow and out layer of onion, red pepper and dried laver. The main antioxidant component in the epicarp of avocado was isolated in the eluate with CHCl3-ethylacetate (1:1) by silica gel column chromatography after the extraction with methanol, water and then ethylacetate, and it was determined to be l-epicatechin on thin layer and paper chromatographies.