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.

Antioxidant properties of Amaranthus hypochondriacus seeds and their effect on the liver of alcohol-treated rats.

Amaranth constitutes a valuable pseudocereal, due to its nutritional quality and its nutraceutical properties, which contribute to improve human health. This work evaluated the effect of a diet based on Amaranthus hypochondriacus (Ah) seed on oxidative stress and antioxidant status in the liver of rats sub-chronically exposed to ethanol. The seed extract was investigated for antioxidant capacity in vitro, showing an adequate content of total phenols and antioxidant activity elevated. For in vivo assays, four groups of six rats each were fed with an AIN-93 M diet for 28 days. In groups III and IV casein was replaced by Ah as the protein source; groups II and IV were received ethanol in the drinking water (20% v/v). When comparing groups IV and II, the following was observed: significant decrease in the activity of aspartate aminotransferase and content of malondialdehyde (p<0.001) in serum; decrease of malondialdehyde and increase in the activity and gene expression of Cu,Zn-superoxide dismutase, also, decrease in the NADPH oxidase transcript levels (p<0.05) in liver. Our data suggest that Ah is a good source of total phenols and exerts a protective effect in serum and in liver of rats intoxicated with ethanol.