THE DIGESTIBILITY OF TEPARY BEANS 1 
By Harry J. Deuel 
Formerly with the Office of Home Economics, United States Department of 
Agriculture 
The tepary bean, Phaseolu-s acutifo- 
lius, is a native North American crop 
plant and has long been grown in So¬ 
nora, Mexico, and in Arizona, by the 
Indian agriculturists. Bailey (l, p . 
Jj.62-^63) 2 states that the Papago and 
Pima Indians cultivated tepary beans 
from prehistoric times and “in all prob¬ 
ability they formed one of the principal 
food crops of that ancient and unknown 
agricultural race.” The plant forms 
a low, trailing bush, with many slender, 
diffuse branches which lie close to the 
soil. Tepary beans are distinctly a 
dry-land crop grown for the beans and 
rarely if ever for forage. The con¬ 
tinuous growth with formation of seed 
pods, which is characteristic unless 
frost or disease interferes, is a disadvan¬ 
tage if the beans are grown in the 
moister regions of the United States. In 
the dry regions it appears that tepary 
beans will make a larger crop on less 
rain than any other known species of 
bean. There is therefore a large range 
of territory in California, Arizona, and 
New Mexico where their culture could 
be widely extended if a regular market 
demand existed for them. 
The largest extension of tepary-bean 
culture probably took place in 1917, 
when California alone produced over 
150,000 bushels. The market price 
was not satisfactory, and later crops 
have been considerably smaller. 
Although somewhat smaller than 
navy beans the tepary resembles them 
very closely and may be readily mis¬ 
taken for them. Forty-seven color 
types have been isolated by the Arizona 
Agricultural Experiment Station, but 
only the white tepary beans have en¬ 
tered bean-trade channels of the United 
States. Considerable attention has been 
given to tepary beans and their culture 
and use as food at the Arizona Agricul¬ 
tural Experiment Station (4) and the 
California Agricultural Experiment 
Station (5, 17). 
Much is known about beans and 
other common legumes as food, as a 
result of experiments carried on by 
many investigators. However, in the 
case of the tepary bean little informa¬ 
tion has been available with respect 
to food value beyond the analyses 
showing the chemical composition the 
fact that this bean is an important food 
crop where grown, that it is whole¬ 
some, well flavored, may be prepared 
in much the same ways as other dry 
beans, and that it is held to be a nutri¬ 
tious and sustaining food by those who 
have long used it. As in the case of 
most dry beans soaking is a necessary 
preliminary to cooking, or at least it 
shortens the cooking period. It is 
interesting to note that when soaked 
the skin of tepary beans wrinkles more 
quickly than does that of navy beans. 
In preparing tepary beans for the 
table Jaffa (17) recommends soaking 
them for 15 to 30 minutes and then 
draining and boiling in fresh water for 
about three hours. 
Of beans, peas, and other dry 
legumes it may be said that they 
provide protein and carbohydrates 
(chiefly starch) in about equal amounts 
and in many cases some fat. That 
the range is rather wide is evident 
when one recalls that the soybean, 
like the peanut, is rich in fat, but 
when well ripened it contains no car¬ 
bohydrate in the form of starch. In 
these respects the tepary bean obviously 
resembles the navy bean rather than 
the peanut or the soybean. With 
respect to the digestibility of the more 
common legumes, considerable infor¬ 
mation is available, chiefly as a result 
of investigations carried on by the 
United States Department of Agri¬ 
culture and its collaborators. 
A series of 70 experiments on the 
digestibility of navy beans, red kidney 
beans, and several varieties of cowpeas 
was made at the University of Ten¬ 
nessee (31). Generally speaking, the 
experiments show that the legumes 
were as well digested and assimilated 
as are the coarser cereal products, and 
that in some instances the digestibility 
was as great as that of the finer grades 
of flour. The investigations as a 
whole, it is stated, demonstrate the 
1 Received for publication June 21, 1924—issued January, 1925. 
2 Reference is made by number (italic) to “Literature cited,” pp. 205-208. 
Journal of Agricultural Research, 
Washington, D. C. 
( 205 ) 
Vol. XXIX, No .4 
Aug. 15, 1924 
Key No. T-l 
