Phytochemical screening and antibacterial properties of selected Nigerian long pepper (Capsicum frutescens) fruits

Five varieties of Nigerian long pepper (Capsicum frutescens) fruits (var. baccatum, chacoense, fingerh, maxima and minima) were studied for their antibacterial activities. Methods described by Association of Official Analytical Chemists (AOAC) were employed to determine the phytochemicals in the pepper fruits. The Capsicum frutescens fruits showed antibacterial activity (10.33 - 32.66 mm zones of inhibition) against all the tested pathogenic bacteria. The minimum inhibitory concentrations for the peppers range between 7.8 and 37.5 mg/ml. Pepper var. minima had the highest MIC (37.5 mg/ml) while pepper var. fingerh exhibited the lowest MIC (7.8 mg/ml) against Pseudomonas aeruginosa and Salmonella typhi, respectively. The flavonoids, tannins, alkaloids and saponins found present in the extracts were quantified as 0.0019-0.0043, 0.0084-0.0146, 6.57-15.78 and 15.67-26.29 mg/ml, respectively. From this study, it was concluded that the long peppers have antibacterial effect on the tested food borne pathogens; even the less pungent C. frutescens var. fingerh showed antibacterial activity. These peppers when consumed raw could prevent elaboration of infection that the test pathogenic bacteria could cause if consumed in foods.