Introduction: Consumption of fruits and vegetables helps to scavenge free radicals owing to the presence of antioxidant nutrients and secondary metabolites, especially polyphenolic compounds. This may lead to a reduction in the risk of diet-related chronic diseases. The purpose of the study was to determine the antioxidant capacity (AC) and total phenolic content (TPC) of selected seasonal fruits of Bangladesh.
Methods: Hydrophilic extracts from edible portions of fifteen fruits available in the summer season were analysed. Total phenol content was determined spectrophotometrically according to the Folin-Ciocalteau method while antioxidant capacity was determined by 2, 2-diphenyl-1-1-picrylhydrazyl radical scavenging activity (DPPH-RSA).
Results: TPC ranged from 0.6 +/- 0.01 to 0.01 +/- 0 mg Gallic acid equivalent (GAE)/g of fresh weight (FW). Antioxidant capacity varied from 4.882 +/- 0 to 0.113 +/- 0.03 micromol Torolox equivalents (TE)/g of FW. Carissa carandas showed the highest AC (4.882 +/- 0 micromol TE/g), while the lowest (0.113 +/- 0.3 micromol TE/g) was seen in Baccaura ramiflora. A positive and significant correlation (R2 = 0.957) between antioxidant capacity and total phenolic content of the analysed samples was identified. A significant and positive correlation (p < 0.05) between AC and TPC was found in Manikara zapota, Artocarpus heterophyllus, Litchi chinensis and Articarpus lakoocha.
Conclusion: The data indicates that some indigenous seasonal fruits of Bangladesh contain high polyphenols that may serve as a potential source of dietary antioxidants.