Evaluation of the nutritional quality of the grain protein of new amaranths varieties.

The efforts for promoting the consumption of food of plant origin are increasingly growing. The amaranth grain is an important vegetable protein source, superior in content and quality to traditional cereals. In the central-west region of Argentina, new amaranth varieties have been obtained to optimize its agronomic traits and promote its use. In this work, the analysis of the wholemeal flour protein from seeds of two new varieties of Amaranthus cruentus var. Candil (CC) and Amaranthus hypochondriacus var. Dorado (HD), as well as from advanced lines of Amaranthus hypochondriacus x Amaranthus cruentus H17a (H17) and Amaranthus cruentus G6/17a (CG6), was carried out in order to elucidate their nutritional contribution to human diet. The amino acids profile and the chemical score (CS) were determined, and the protein quality was evaluated in-vivo through the following indexes: net protein utilization (NPU), true digestibility (tD), biological value (BV) and protein digestibility corrected amino acid score (PDCAAS). In general, the amino acids values of the different varieties exceeded the requirements established by the WHO/FAO/UNU; however, valine was the limiting amino acid in all cases. The values obtained (%) were within the following ranges: NPU, 33.56-46.04%; tD, 68.80-75.40%; BV, 44.53-64.28%; and PDCAAS, 23.69-36.19%. These results suggest that the new amaranth flours varieties can be adequate for human consumption and as complementary protein source.