NUTRITIVE VALUE OF LEAF PROTEIN CONCENTRATES PREPARED FROM Amaranthus SPECIES

Abstract

Leaf protein concentrate (LPC) samples were prepared from several species of Amaranthus. Their proximate composition and phenolic content were determined. In vitro nitrogen digestibility was low (28–48%) and was negatively correlated with phenolic content. The amino acid content of one sample of A. hypochondriacus LPC was measured, and compared favorably with reported values for essential amino acids for alfalfa LPC and soybean meal. The nutritional values of the LPC samples were assessed in a rat feeding trial. Compared to a soybean meal control diet, the gains with Amaranthus LPC were poor, ranging from 18 to 72% of the control value. The cause of the poor growth remains to be determined. The high ash content of the samples, or the presence of organic factors such as saponins, phenolics and oxalates are possibilities to account for the poor growth rate of rats.