Chemical constituents, in vitro protein digestibility, and presence of antinutritional substances in amaranth grains.

The chemical composition, content of antinutritional factors, and the in vitro protein digestibility of grains of the pseudo-cereal Amaranthus were analyzed. The plants were grown in Brazil (without fertilizer), Puerto Rico (100 kg N/ha), and California (200 kg N/ha). The seed analysis gave the following values (%DM): 14.4 - 16.9 protein (N X 6.25), 4.8 - 6.8 fat, 2.5 - 3.9 ash, and 2.3 - 2.9 crude fiber. The trypsin inhibitors, phenolics and saponine contents were low, and the phytohemagglutinin activity, fairly low. The in vitro protein digestibility was 61 - 76%. Digestibility was not correlated to the analyzed proximal composition nor to the antinutritional factors. The grain composition indicates a food value equivalent to that of conventional food grains.