THE DIGESTIBILITY OF SOY BEAN MEAL BY MAN.* 



By j. F. LYiMAN and W. G. Bowkrs, 



There always has been considerable interest, in connection 

 with human nutrition, in the seeds of the legumes. The common 

 white or navy bean has played a prominent part in the affairs 

 of the United States in supplying nourishment to soldiers in the 

 service and to laborers on the farm and in the factory. The 

 bean has been recommended as the "poor man's beefsteak," 

 supplying as does meat, large quantities of proteins. 



In China and Japan another legume, the soy bean, is exten- 

 sively used as human food. This is ordinarily prepared for the 

 table by processes not in general use in this country, usually 

 involving some kind of fermentation. These preparations supply 

 a very important part of the food requirement, especially of the 

 protein requirement, of the Chinese and Japanese, and have 

 been found to be well utilized in the body, in some cases 96 per 

 cent of the protein being absorbed.^ 



The soy bean has been cultivated rather extensively in the 

 United States in recent years, but it has been used almost 

 entirely as forage or for animal feed. Recently a soy bean 

 meal, a by-product in the manufacture of soy bean oil, has 

 been produced in considerable amounts in some sections of the 

 South. The composition of this material and of the whole beans 

 in comparison with common white beans suggests that we have 

 here valuable supplies of human food which should not be 

 neglected. The following table gives the average composition of 

 the different materials. 



^White beans (dry) . 



^Soy beans 



Soy bean meal 



Moisture 

 Percent 



12.6 



10. n 



.3.7 



1 



Protein 

 Percent 



Fat 



Fiber 



Percent Percent 



22.5 



38.29 



46.66 



1.8 



14.89 



5.1 



4.4 



4.64 



5.5 



N-free 

 Extract 

 Percent 



Ash 

 Percent 



55.2 



26.64 



32.3 



3.5 



5.54 



5.75 



Obviously, chemical analyses alone do not measure the 

 nutritive value of food. We must know also the digestibility of 

 the food, the relative quality of its proteins, carbohydrates, 

 fats and minerals, the extent to which accessory substances or 

 vitamines occur, and finally whether, for any reason, it exerts a 

 harmful influence on the body. 



* From the Laboratory of Agricultural Chemistrj^ and Soils, The Ohio State 

 University, Columbus. 



279 



