Chemical characterization of Brazilian hulless barley varieties, flour fractionation, and protein concentration

Abstract

Even though hulless barley is widely known due to its nutritional potential, in Brazil it is only grown at a few agricultural experimental stations. There is no published data about the chemical composition of Brazilian hulless barley varieties; however, research laboratories have studied their agronomical characteristics. The objectives of this study were to present the chemical characterization and effect of flour fractionation on protein concentration of six Brazilian hulless barley varieties, namely IAC IBON 214/82, IAC 8612/421, IAC 8501/31, IAC 8501/12, IAPAR 39-Acumaí, and IAC 8501/22. The analyses included: ash, ether extract, total protein, starch, total insoluble and soluble dietary fiber, and beta-glucans. Flour fractionation was carried out by sieving. The flour fractions were evaluated for crude protein, protein, and protein and non-protein nitrogen. Chemical composition varied (P < 0.05) among all the varieties. IAC 8501/22, IAC 8501/31, and IAC 8501/12 showed the highest protein content (15.69, 15.25, and 14.94% respectively). Differences (P < 0.05) among the protein of the fractionated flours were detected, and might be attributed primarily to genetic background since all varieties were grown under the same environmental conditions. Fractionating the flour increased the total protein content, in some fractions, by up to 2%. These results may be useful in the food industry for the selection of hulless barley varieties for human consumption and to produce substantially protein-enriched flour fractions.