206 
Journal of Agricultural Research 
Vol. XXIX, No. 4 
important place which legumes may 
fill in the diet as economical and 
palatable sources of protein, though 
later studies have shown that most 
legume proteins can not be considered 
complete. However, a diet .containing 
meat, milk, eggs, and similar foods 
would supply this deficiency. 
Digestion experiments have been 
made in connection with the food work 
of the United States Department of 
Agriculture with soybeans and with 
peanuts (15) cooked until soft in a 
household pressure cooker. The le¬ 
gumes formed the principal part of a 
simple mixed diet. The experiments 
show that steam-cooked peanuts were 
well assimilated, the coefficient of di¬ 
gestibility of the protein being 79.9 
per cent. Large quantities of these 
legumes were consumed throughout 
the experiments, no physiological dis¬ 
turbances being noted. The report 
also points out that as regards nutri¬ 
tive and biological value, there is 
evidence to justify the belief that 
soybeans and peanuts are especially 
valuable as food in comparison with 
other legumes which had been simi¬ 
larly studied. The literature of this 
phase of the subject is summarized in 
the bulletins cited. 
EXPERIMENTAL METHODS 
The experimental methods used 
with tepary beans were those followed 
in digestion experiments conducted by 
the United States Department of Ag¬ 
riculture and described in earlier publi¬ 
cations (2, 8, 6, 7, 8, 9, 10, 11, 12, 18, 
14, 15, 16, 18, 19, 20, 21, 22, 28, 24, 
25, 26, 27, 28, 29). 
The subjects were men apparently 
in good health and well instructed in 
the experimental routine. The neces¬ 
sary analyses of food and feces were 
made by standard methods. The 
tepary beans used in the experiments 
were obtained through the courtesy of 
one of the correspondents of the de¬ 
partment. The beans were prepared 
by soaking over night and then cooking 
for an hour under 15 pounds pressure. 
The beans were eaten with a basal diet 
of bread, butter, fruit, and sugar. 
The results of the five experiments are 
summarized in Table I. 
Table I .—Summary of digestion experiments with tepary beans in a simple 
mixed diet 
Experiment No. 
Digestibility of entire ration 
Estimated 
digesti¬ 
bility of 
tepary 
bean 
protein 
Estimated 
digesti¬ 
bility of 
tepary 
bean carbo¬ 
hydrate 
Protein 
Fat 
Carbo¬ 
hydrate 
Ash 
901...... 
902.. ....... 
903_____ 
904.. .____ 
905...... 
Average___ 
Per cent 
86.3 
78.7 
80.4 
73.4 
82.8 
Per cent 
93.8 
92.3 
94.2 
91.9 
93.7 
Per cent 
98.1 
98.2 
98.1 
96.7 
97.9 
Per cent 
81.4 
75.6 
77.3 
65.9 
72.9 
Per cent 
84.8 
74.4 
74.6 
67.1 
78.7 
Per cent 
97.9 
100.0 
98.4 
96.4 
97.4 
80.3 
93.2 
97.8 
74.6 
75.9 
98.0 
The subjects ate, on an average, 70 
gm. of protein, 69 gm. of fat, and 394 
gm. of carbohydrate, with an energy 
value of 2,475 calories, per man per day. 
The beans supplied on an average 40 gm. 
of protein and 99 gm. of carbohydrate 
per man per day. The protein of the 
beans was 76 per cent utilized, which 
agrees closely with the value of 78 per 
cent for navy and red kidney beans 
found by Wait (81), and 77.9 per cent 
found by Mendel and Fine (80) for navv- 
bean protein. The carbohydrates of 
the tepary beans were on an average 98 
per cent digested, which represents 
almost complete utilization and is 
somewhat higher than the value of 96 
per cent found by Wait for navy-bean 
carbohydrates. The subjects reported 
that they remained in their usual 
normal health throughout the ex¬ 
perimental period. 
SUMMARY 
A study of the digestibility of tepary 
beans for purposes of comparison with 
similar legumes shows that tepary 
beans are well utilized by the body 
and are a valuable food. 
