Bioactive polyphenols and peptides in cowpea (Vigna unguiculata) and their health promoting properties: A review

Cowpea is a drought and heat tolerant grain pulse. It contains high levels of polyphenols, with some profiles not commonly found in other pulses. The major polyphenols common to all cowpea varieties are phenolic acids derivatives (148-1176 μg/g), and flavonol glycosides (27-1060 μg/g). Some varieties also contain anthocyanins (875-3860 μg/g), and/or flavan-3-ols (2155-6297 μg/g). The flava-3-ols (tannins) are dominated by monomers, mostly catechin-7-O-glucoside. This likely makes cowpea tannins more bioavailable, while limiting their potential antinutritional properties. Cowpea also contains beneficial bioactive peptides. Evidence suggests significant anti-inflammatory effect, and benefits against cancer, diabetes, and cardiovascular disease of cowpea polyphenols and peptides, with potential synergistic interactions. Polyphenol profile has a major impact on these properties, thus varieties can be selected for targeted benefits. With its agronomic advantages, nutritional, and health benefits, cowpea is likely to play an increasing role as ingredient in modern food applications.