Relative Efficiency of the Proteins in Polished Rice and in Enriched Wheat Flour. ∗

Abstract

While a review of the literature discloses that on the same protein intake (5% level) the proteins in whole rice are superior to those in corn and oats, 1 no information was found on the relative biological values of the proteins in polished rice and milled wheat flour, fed on the same protein intake.

During the past year and a half, while engaged in studies on the influence on growth and protein utilization of additions of small amounts of cultured food yeasts to the proteins of cereal flours and cereal grains, it was observed that, on the same protein level in the ration, the proteins in polished rice are far superior to those in enriched white flour. Polished rice fed at an 89% level and enriched wheat flour fed at 57% plane of intake furnished the same 5.8% protein in the ration. The rations contained 2% cellu flour for roughage; 2 % cod liver oil and 3% wheat germ oil as sources of fat-soluble vitamins, and a complete salt mixture. 2 Cerelose (dextrose) constituted the rest of the rations. An abundance of the vitamin B complex was furnished daily to each animal separately from the ration. The composition of the vitamin B complex mixture was as follows: 100 μg thiamin, 100 μg riboflavin, 100μg pyridoxine, 600 μg calcium pantothenate, 100 μg nicotinic acid, 12 mg choline chloride, 12 mg p-aminobenzoic acid, and 3 mg inositol. The protein efficiency is expressed as gains in weight per gram of protein intake. The experimental period was 10 weeks.

Twelve animals on 9% enriched patent wheat flour proteins showed an average gain per animal of 42.2 g and the proteins had an efficiency of 0.88, while on 5.8% wheat flour proteins in the diet, 12 animals made an average gain per animal of 19.3 g and the protein efficiency on this level of intake was 0.72. On the other hand, 30 animals on 5.8% proteins in polished rice made an average gain per animal of 74 g and the efficiency of the rice proteins was 1.86.