Flavonoids and tannin composition of Bambara groundnut (Vigna subterranea) of Mpumalanga, South Africa

Abstract

Bambara groundnut (Vigna subterranea) an indigenous legume proclaimed to have medicinal properties within rural areas. Therefore, this study aimed to identify possible medicinal properties of Bambara groundnut (BGN). Flavonoids and tannins were highly concentrated in the red and brown BGN hulls. Among the flavonoid compounds rutin was observed in highest concentrations in brown hull (24.458 ± 0.234 mg g−1) and myricetin (1.800 ± 0.771 mg g−1). While among tannin compounds chlorogenic acid was found in highest concentrations (0.115 ± 0.199 mg g−1) and ellagic acid in red hull (0.105 ± 0.082 mg g−1). The form and colour of the BGN were all important factors to optimize the best extraction yield of phytochemicals. Overall the hulls of the BGN were the optimum source of flavonoids and tannins.