Antioxidant Activity of Fresh Fruits and Dry Fruits

Abstract

The antioxidant activity from methanol extract of fresh fruits and dry fruits of 14 Thai fruits were determined using free radical scavenging method (DPPH method) and Folin - Ciocalteu’s reagent (FCR assay). We found that methanol extract of fresh fruits and dry fruits of Indian gooseberry and mangosteen peel showed the highest antioxidant activity with DPPH in IC50 0.74 and 1.30 ppm in fresh fruits, 0.81 and 1.98 ppm in dry fruits, respectively. Compare with the controls, vitamin C and vitamin E showed 1.90 and 2.52 ppm, respectively. While methanol extract for all of fresh fruits and dry fruits showed the antioxidant activity with DPPH in IC50 in range 18.65 to more than 500 ppm in fresh fruits and 21.79 to more than 500 ppm in dry fruits, respectively. The total phenolic content using FCR assay for methanol extract of fresh fruits and dry fruits, Indian gooseberry showed the highest total phenolic content in 10.060 ± 0.002 and 9.500 ± 0.003 mg GA/g extract, respectively. While mangosteen peel showed total phenolic content of methanol extract from fresh fruits and dry fruits in 5.380 ± 0.002 and 4.540 ± 0.002 mg GA/g extract, respectively.  For the sweetness of fresh fruit, we found that Musa ABB cv. Kluai Namwa showed the highest of sugar content in 27.5% Brix, while the other fruits except mangosteen peel and tangerine peel had not been to determined showed sugar content in the range 4.5 to 20.4 %Brix. From this research, we can maintain that the antioxidant activity of fresh fruits is higher than dry fruits (drying at 60 °C) and the antioxidant activity is not concerned to the sweetness