Idenfication of Nutraceutical Phenolic Compounds in Bambara Groundnuts (Vigna subterranea L. Verdc) by HPLC-PDA-ESI-MS

Abstract

Aim: The aim of the study was to explore the nutraceutical potential of bambara groundnuts (Vigna subterranea L. Verdc) commonly grown in Zambia based on the phenolic phytochemical profiles. Methodology: Two market classes of bambara groundnuts (red and brown) commonly grown in Zambia were screened in raw dry form. The study employed the High Performance Liquid Chromatography-Photo Diode Array-Electrospray Ionization-Mass Spectrometry (HPLC-PDA-ESI-MS) to screen for phenolic phytochemical profiles of the 70% methanol extracts from bambara groundnuts Results: HPLC-PDA-ESI-MS- based identification revealed the presence of various phenolic compounds, mainly phenolic acids and flavonoids. In both the red and brown bambara groundnuts, the following phenolic compounds were tentatively identified: Quinic acid, (E) GC-hexoside, catechin glucoside, catechin, epicatechin, medioresinol, p-coumaric acid, salicylic acid, caffeic acid derivative and catechin dimer. The red bambara groundnuts revealed the following phenolic compounds that were absent in the brown: myricetin hexoside, quercetin-3-O-rutinoside and quercetin-3-O-glucoside. Conclusion: The nuts contain various polyphenolic compounds, mainly from the class of flavonoids. It is suggested that consumption of bambara groundnuts could possibly offer some health benefits since they contain phytochemical constituents that have been reported to possess protective functions. These data indicate that bambara groundnuts studied have the potential for use as nutraceuticals.