Antioxidant compounds of dietary plants have been widely studied because of their bioactive properties. The objective of this research study was to analyse the health enhancing attributes of 31 cowpeas varieties from Burkina Faso. Significant variations were observed in the phenolic content as well as the antioxidant and anti-lipid peroxidation activities amongst the cowpea varieties. Pearson correlation coefficient analysis showed that the ferric reducing ability (r = 0.954) and anti-lipid peroxidation (r = 0.616) were positively correlated with the total phenolic content. A significant relationship between cowpea ferric reducing ability and anti-lipid peroxidation (r = 0.64) was also revealed. However, nitric oxide scavenging potential was found not to be related to its total phenolic and total flavonoid content. 2,2-diphenyl-1-picrylhydrazyl (DPPH) and hydroxyl radicals scavenging potentials were not correlated with the total flavonoid content. The pigmented seeds of cowpea varieties possess higher total phenolic, total flavonoid content, ferric reduction ability, and anti-lipid peroxidation activities than the colourless ones. The results obtained from this study suggest that Burkina Faso cowpea cultivars are rich in phenolic compounds and have significant antioxidant and anti-lipid peroxidation activities. Consumption of the cowpea, particularly of coloured cowpea seed varieties, should be beneficial for chronic human diseases prevention.
Keywords: Vigna unguiculata; antioxidant activities; genotype; phenolic content.