Antibacterial and antioxidant activities of local seeded banana fruits

The antibacterial and antioxidant activities of different parts of local seeded banana fruit were investigated in vitro. Dried peels, pulps and seeds of the fruit were extracted with hexane, ethyl acetate and ethanol. Antibacterial property of the extracts was evaluated against four Gram positive and four Gram negative bacteria using disc diffusion technique. Ethyl acetate and ethanol extract of both pulp and peel exhibited antibacterial activity with zone of inhibition ranging from 9 to 24 mm. On the other hand, only ethyl acetate extract of seeds showed antibacterial activity and the zone of inhibition ranged from 8.5 to 10 mm; interestingly, none of the hexane extracts of the three banana parts exhibited zone of inhibition. Antioxidant activity of the extracts was evaluated by total phenolic content determination and 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging assay. Total phenolic content expressed as gallic acid equivalents (GAE) was found to be highest in ethyl acetate extract of banana seed (19.46 mg GAE/g extract) followed by the same extract of banana pulp (15.78 mg GAE/g extract) and peel (11.23 mg GAE/g extract). High free radical scavenging activity was observed with ethyl acetate extracts of banana seed, peel and pulp with an ascorbic acid equivalent antioxidant capacity (AEAC) value of 1238.33, 1011.43 and 588.03 mg AA/100 g extract, respectively.