Preliminary Studies on the In vitro Antioxidant Potential and Vitamin Composition of Selected Dietary Fruits Consumed in Alice region of South Africa

The present study investigated total phenols, flavonoids and vitamins composition in a selection of fruits; {orange (Citrus sinensis), red apple (Mallus pumila), carrot (Daucus carota), pear (Pyrus calleryana), golden apple (Mallus pumila), pawpaw (Carica papaya), pineapple (Ananas comosus) and banana (Musa acuminate)} consumed in Alice region of South Africa. The antioxidative capacity of these fruits were also determined using ferric reducing power, Lipid Oxidation (LO), 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2'-azino-bis-3 ethylbenzothiazoline-6-sulfonic-acid (ABTS), Nitric Oxide (NO) and hydroxyl (OH) radicals. The contents of vitamin B2, B3 and vitamin C were also noted using standard methods. A significant variation in the phenols, flavonoids and vitamins contents across the fruit samples was observed. All the fruits tested besides pineapple showed a good reducing antioxidant power in a concentration dependent manner. The extracts of pawpaw, orange, banana and red apple relatively had higher antioxidant potential against DPPH and ABTS radicals among others. The fruits samples demonstrated considerable antioxidant potential against OH* and LO with IC50 values range from 0.511-1.067 mg mL-1 and 0.53-0.818 mg mL-1, respectively. Some of the fruit samples depicted reasonable antiradical potential against NO* with IC50 range from 1.035-1.513 mg mL-1. The fruits extract contained relatively higher concentration of vitamin C, vitamin B2 and vitamin B3 whereas pineapple and red apple extracts had lower content of vitamin B2. Unfortunately, both vitamins (B2 and B3) were not found in banana. The result of antioxidant activities of these fruits provide evidences to support consumption practice of fruits varieties in the region to compensate nutrient deficiency and therefore could be a useful source to prevent diseases related to oxidative stress.