TOTAL ANTIOXIDANT CAPACITY OF FRUITS

The total antioxidant activity of 12 fruits and 5 commercial fruit jui ces was measured in this study using automated oxygen radical absorban ce capacity (ORAC) assay. On the basis of the wet weight of the fruits (edible portion), strawberry had the highest ORAC activity (micromole s of Trolox equivalents per gram) followed by plum, orange, red grape, kiwi fruit, pink grapefruit, white grape, banana, apple, tomato, pear , and honeydew melon. On the basis of the dry weight of the fruits, st rawberry again had the highest ORAC activity followed by plum, orange, pink grapefruit, tomato, kiwi fruit, red grape, white grape, apple, h oneydew melon, pear, and banana. Most of the antioxidant capacity of t hese fruits was from the juice fractions. The contribution of the frui t pulp fraction (extracted with acetone) to the total ORAC activity of a fruit was usually less than 10%. Among the commercial fruit juices, grape juice had the highest ORAC activity followed by grapefruit juic e, tomato juice, orange juice, and apple juice.