Chemical and mineral composition of the raw and cooked immature grains of cowpea genotypes

Abstract

Immature cowpea grains are a rich source of proteins, minerals, dietary fiber, and phenolic compounds and also have a high antioxidant capacity compared to dry grains. Its consumption promotes a healthy and diversified diet. The objective of this work was to evaluate the cooking time and chemical and mineral composition of the raw and cooked immature grains of different cowpea genotypes. Four genotypes, two elite lines (MNC00-595F-27 and MNC05-847B-123) and two commercial cultivars (BRSTumucumaque and Vagem Roxa-THE) were analyzed. Cooking time was evaluated using the Mattson cooker. Proximate composition and minerals were determined. A completely randomized design with three replications in factorial scheme 1 (genotype) × 2 (raw and cooked grains) was adopted, except for cooking quality. The genotypes MNC05-847B-123 and BRS-Tumucumaque differed from the other genotypes, presenting faster cooking of the immature grain. Cooking increased the moisture content and reduced ash, lipid, protein, and carbohydrates contents and total energy value. The lines MNC05-847B-123 and MNC00-595F-27 showed higher contents of the nutrients of the centesimal composition after cooking than the local cultivar Vagem Roxa-THE, except for the moisture content. The mineral content decreased after cooking, with Fe, Zn, and Mn contents having the least losses with thermal processing. The lines MNC05-847B-123 and MNC00-595F-27, even with losses after the thermal processing of the immature grain, have nutritional potential as cultivars for the green-bean market.