All-Vegetable Protein Mixtures for Human Feeding

Abstract

A series of experiments carried out to test the nutritive value and lack of toxicity of INCAP Vegetable Mixture 9, was discussed. The mixture contains in per cent: corn, 28; sorghum grain, 28; cottonseed flour, 38; Torula yeast, 3; and leaf meal, 3. Any corn-sorghum proportion can be used without altering the nutritive value of the mixture, and other cereal grains and carbohydrate-rich seeds can replace the corn and sorghum. Among these, buckwheat and rice were found to be particularly good substitutes to improve chick growth and feed utilization. Other cereal grains or grain products tested were barley, oats, whole wheat and wheat flour. The Torula yeast contributes significantly toward the protein value of the mixture for chicks. When brewers' yeast was substituted, the bitter taste resulted in poor growth and feed efficiency due to a lowered feed consumption. The several carotene-rich leaf meals tested did not contribute to the protein quality of the mixture. Because of this finding and the technical difficulties encountered in the preparation of good quality leaf meals, synthetic vitamin A preparations are recommended as substitutes. The addition of 0.1% of L-lysine hydrochloride to the mixture brought about improved growth response in chicks suggesting that the mixture was limiting in lysine, although according to calculations based on microbiological amino acid analyses, lysine was not a deficient amino acid. The response to lysine supplementation was explained by the finding that lysine availability for the chick in the cottonseed flour used was only about 83%. The addition of 0.1% of methionine did not improve growth or feed efficiency either alone or in combination with lysine. It was concluded that Vegetable Mixture 9 is of high nutritional value and of potential value in human feeding.