Proteínas e fenólicos totais hidrossolúveis de diferentes Grãos de bico (Cicer arietinum L.) cultivados no Brasil

Abstract

Legumes such as chickpeas, soybeans, and beans are associated with promoting human longevity, and part of this association is attributed to the protein composition of these legumes, as well as the presence of other bioactive components. Among the various legumes incorporated into the human diet, chickpeas stand out. Their protein content is considered high, with a notable profile of amino acids and potential for the release of bioactive peptides. In Brazil, some cultivars are already adapted to cultivation, and new strains under study are proving promising, especially browncolored desi-type beans with colored husks. Forms of legume consumption include cooked grains, bread, and beverages, among others. Aqueous vegetable-based extracts have shown a growing market alternative and may have a high protein content depending on the plant source, such as legumes. Their composition will depend on the composition of the grains, especially the water-soluble material. In addition to proteins, peptides, and amino acids, other compounds may make up the set of soluble components present in the final product, potentially impacting human health. Thus, the objective of this work was to evaluate the water-soluble compounds of 10 different samples of chickpeas (Cicer arietinum L.) cultivated in Brazil, including 4 kabuli-type samples with cream coloration and 6 desi-type samples with browncolored husks, especially focusing on those with potential bioactivity. Determinations were made for grain color, proximate composition, protein solubility, protein inhibitors, total phenolics, total flavonoids, and antioxidant activity of aqueous extracts. Electrophoretic profiles and total free alpha-amino group concentrations of the extracts were also determined. The grains showed total protein contents between 16.08% and 23.70%, of which the soluble fraction ranged from 48.23% and 73.68%, with the presence of protease activity and trypsin inhibitor activity. Extracts produced from brown grains exhibited higher antioxidant activity, particularly in assays with DPPH, compared to assays with ABTS. This activity may be a reflection of the higher content of soluble phenolics and flavonoids from the husks, which had levels up to 10 times higher than those of the cream-colored husks. These data suggest that beverages based on these grains should consider their preparation with the presence of the husks, which contain water-soluble compounds potentially promoting human health. Furthermore, the proteins from fresh grains were found to be easily extracted 8 in water, with solubilities higher than expected, indicating a high potential for application in protein beverage production.