DIGESTIBILITY OF SOY-BEAN AND PEANUT FLOUBRS. 19 
In the experiments with soy-bean flour the subjects ate on.an | 
average 84 grams of protein, 92 grams of fat, and 268 grams of carbo- 
hydrate per man per day. The coefficients of digestibility for the 
entire diet were, for protemm 86.6 per cent, for fats 94.2 per cent, 
and for carbohydrate 96.3 per cent. The digestibility of soy-bean 
protein was estimated to be 85.3 per cent. Referring to pages 
2 and 3 it will be noted that the digestibility of the proteins of com- 
mon legumes, as shown by numerous studies made by well-known 
investigators, is noticeably lower than this. It is quite possible that 
the method of preparation and of cooking may affect the digesti- 
bility to some extent, since in grinding the press cake the cells are 
without doubt quite thoroughly broken up. However, in those 
studies in which peas were served in the form of a purée the cells were 
also very thoroughly broken. The digestibility of soy-bean protein 
(85.3 per cent) compares very favorably with that of the common 
cereals. 
Of the 84 grams of protein eaten daily 82 grams were supplied 
by the soy-bean biscuits. Since approximately 85 per cent of the 
total protein of the biscuits was soy-bean protein, the subjects ate 
on an average 70 grams of soy-bean protein daily. Inasmuch as none 
of the subjects reported any physiological disturbances as a result of 
this diet, it appears that soy-bean protein is well tolerated by the 
human body. 
The results of the experiments in general indicate that protein 
supplied by soy-bean press cake (ground to flour) is well assimilated 
and is too valuable to be overlooked as a human food. 
THE DIGESTIBILITY OF PROTEIN SUPPLIED BY PEANUT PRESS- 
CAKE FLOUR. 
As previously noted on page 13, two types of peanut flour. were 
used in these tests, namely, one made by grinding the press cake 
resulting from the expression of oil from roasted, degermed peanuts, 
and the other by grinding the press cake remaining after the ex- 
pression of oil from raw shelled peanuts from which the red skin had 
not been removed. The roasted peanut flour was of a golden yellow 
color and that from the raw peanuts was of a decidedly red tinge. 
Seven experiments were made with flour made from roasted peanuts 
and four with flour made from raw peanuts. In the first series of 
experiments the ‘‘flour mixture” used for making the biscuits con- 
sisted of two parts wheat flour and one part peanut flour (roasted 
peanuts), and in the second series the ‘‘flour mixture” consisted of 
equal parts of wheat flour and peanut flour (raw peanuts). Since 
the same men served as subjects and uniform experimental condi- 
tions were maintained for both series, the results obtained should be 
directly comparable. 
