The food value of soy bean products

Abstract

Soy beans fed as the sole source of protein, or as a supplement to corn gluten, are suitable for the nutrition of rats. They contain sufficient water-soluble vitamine to promote normal growth; for diets containing soy bean flour, butter fat, starch, and an artificial salt mixture have promoted growth as well as comparable rations containing natural protein-free milk. The presence or absence of the fat-soluble vitamine has not yet been ascertained. The mineral constituents of the soy bean are inadequate for growth. Whether the deficiency is a qualitative or quantitative one remains to be determined. Rats eat foods containing commercial soy bean flour more readily than those containing meal made by grinding the entire seed. The latter is non-toxic; for the few animals which have eaten enough have grown well. Preliminary experiments indicate that the heating to which the commercial soy bean flour is subjected may be the cause of the superiority of the latter. Unlike cotton seed, soy beans extracted with ether are not improved in nutritive value. Unheated soy bean meal and corn gluten has proved satisfactory as the sole source of protein in the diets of chickens. We are continuing our investigation of the nutritive value of this seed.