IDENTIFICATION AND QUANTIFICATION OF PHENOLIC COMPOUNDS AND ANTIOXIDANT ACTIVITY IN COWPEAS OF BRS XIQUEXIQUE CULTIVAR

Cowpea (Vigna unguiculata [L.] Walp.) is one of the most important legumes produced in tropical and subtropical regions throughout the world, especially in the developing countries in Africa, Latin America, and Asia. It is the main source of protein, calories, dietary fiber, minerals, and vitamins for a large segment of the world population. Cowpea is also a potential functional food with a range of bioactive compounds, including phenolic compounds. This legume is grown mainly in the North and Northeast regions of Brazil, but is also consumed in other regions, and is thus important for the farmers who depend on this crop for income. This study identified and quantified phenolic compounds in the cowpea cultivar BRS Xiquexique. Such quantification reveals the functional characteristics of cowpeas, mainly as a source of antioxidants, which will be essential to add value to this food and to expand its forms of consumption. The extracts were analyzed using an HPLC model LC-20AT, equipped with a manual injector. For the HPLC analysis, standard solutions were prepared with pure phenolic acids such as gallic acid, quercetin, caffeic acid, chlorogenic acid, ferulic acid, p-coumaric acid, catechin, and epicatechin. The major phenolic compounds identified were catechin (2.07 +/- 0.329 mg 100 g(-1)), epicatechin (0.48 +/- 0.130 mg 100 g(-1)), gallic acid (67.19 +/- 6.200 mg 100 g(-1)), ferulic acid (32.07 +/- 0.753 mg 100 g(-1)), and chlorogenic acid (3.08 +/- 0.489 mg 100 g(-1)). We observed that the BRS Xiquexique cultivar contains functional phenolic compounds, especially gallic acid and ferulic acid, demonstrating the antioxidant potential of cowpea.