DIGESTIBILITY OF SOY-BEAN AND PEANUT FLOURS. 5 
or by ascertaining the biologic value of the protein by means of care- 
fully controlled feeding experiments with laboratory animals. Such 
experiments give data regarding the ability of a protein to support 
normal life processes, such as growth, maintenance, and reproduction. 
The amount of protein retained for body uses from the food eaten is 
generally determined by digestion experiments in which the protein 
under consideration appears as the sole or major portion of the protein 
in the diet. 
The amount of protein supplied by soy-bean and peanut press-cake 
flours would obviously vary somewhat with the varieties of the 
legumes from which the flours were made and with the process of 
manufacture. Proximate analysis of the dried soy beans and pea- 
nuts shows them to have the following composition: Soy beans,! 
water 9.9 per cent, protein 36.5 per cent, fat 17.5 per cent, carbo- 
hydrates 30.8 per cent, and ash 5.3 per cent, the fuel value being 
approximately 1,950 calories per pound; peanuts’, water 9.2 per 
cent, protein 25.8 per cent, fat 38.6 per cent, carbohydrates 24.4 
per cent, and ash 2 per cent, the fuel value being approximately 
2,480 calories per pound. When the oil is expressed from these 
legumes the percentage of protein is correspondingly increased and 
the resulting commercial press cakes ordinarily contain from 40 
to 50 per cent of protein. The press cakes used in the study here 
reported, which were obtained by expressing oil from soy beans 
and peanuts in a small-sized expeller type of oil press, contained a 
larger amount of protein. But in any case the press cake should be 
classed as protein-rich material and on the basis of chemical analysis 
alone may well be considered as valuable food material. In order to 
ascertain the true value of these proteins for dietary purposes it 
is necessary to consider the factors referred to above, first, the 
- quality of the protein as shown by the nature of the amino acids sup- 
plied and by its biologic value, and second, the digestibility of the 
protein. — 
THE AMINO ACIDS SUPPLIED BY SOY-BEAN AND PEANUT PROTEINS AS 
COMPARED WITH THOSE SUPPLIED BY COMMON CEREAL PROTEINS. 
Since in the commercial utilization of soy-bean and peanut flours as 
human food these flours would, in all probability, be grouped with 
the cereal flours and meals, it is natural to compare the amino acids 
obtained from glycinin, the principal protein of soy beans, and 
arachin, the principal protein of peanuts, with gliadin, zein, rye-pro- 
lamin, oryzinin, and hordein, the principal proteins of wheat, corn, 
rye, rice, and barley, respectively. 
Plant Industry. 
2U.S. Dept. Agr., Office Expt. Stas. Bul. 28 (1899), pp. 75. 
