Deconstructing a fruit serving: comparing the antioxidant density of select whole fruit and 100% fruit juices

Abstract

Research suggests phytonutrients, specifically phenolic compounds, within fruit may be responsible for the putatively positive antioxidant benefits derived from fruit. Given the prominence of fruit juice in the American diet, the purpose of this research was to assess the antioxidant density of fresh fruit and 100% fruit juice for five commonly consumed fruits and juices and to compare the adequacy of 100% juice as a dietary equivalent to whole fruit in providing beneficial antioxidants. Antioxidant density was measured using an oxygen radical absorbance capacity method on six samples assayed in triplicate for each fruit (grape, apple, orange, grapefruit, pineapple), name-brand 100% juice, and store-brand 100% juice. One-way analysis of variance and Tukey's honestly significant difference or Student t test were used to assess significance (P<0.05). Antioxidant density (mmol TE/100 g) of apple, orange, and grapefruit was 23% to 54% higher than the mean antioxidant density of name-brand and store-brand juices for each fruit; however, only apple and grapefruit exhibited significantly greater (P<0.05) antioxidant density than either of their name-brand or store-brand juices. In contrast, the mean antioxidant density of name-brand grape and pineapple juice was higher than fresh grape or pineapple fruit; however, both fresh grapes and commercial grape juice contained significantly more (P<0.05) antioxidants than store-brand grape juice. Regardless of the convenience of fruit juice, results support the recommendations of the 2010 Dietary Guidelines for Americans for increasing fruit servings in the whole fruit form due to their provision of beneficial antioxidants and fiber with approximately 35% less sugar.

Keywords: Antioxidant density; Fruit; Juice; Oxygen radical absorbance capacity (ORAC); Phytonutrients.