Antioxidant Activity and Phytochemical Screening of Five Species of Capsicum Fruits

Abstract

Antioxidants are compounds that help to inhibit many oxidation reactions caused by free radicals. The oxidants activity of five extracts from five varieties of pepper fruits (Solonaceae) were evaluated using the ferric thiocyanates method. The total phenolic content of the extracts was determined spectrophotometrically as tannic acid equivalent. The reducing power was also investigated. The antioxidant activity (% oxidation inhibition) ranged from as high as 78.46% in red bird pepper (Capsicum frutescens) extracts to as low as 10.11% in green pepper fruits (Capsicum annum) extract. Antioxidant activity correlated significantly and positively with total phenolic content (R2 = 0.78), while there was no correlation between total antioxidant activity and reducing power (R2 = -0.46), neither between reducing power and total phenolic content (R2 = -0.56).The phytochemical screening revealed the presence of tannins, flavonoids, saponins, phenols, alkaloids and volatile oils. Pepper fruits studied possess potential health benefits by inhibiting lipid peroxidation hence their use as a value added ingredient. The results indicate that reducing power does not fully characterize the antioxidant activity of the capsicum species studied.