PRODUCTION AND UTILIZATION OF FATS AND OILS 17 
23 per cent. Unless soy beans which contain 17 per cent or more of 
oil can be grown, it is not practical to cultivate them for the expres- 
sion of oil. 
Preparation 
In Europe an increasingly large quantity of soy-bean oil is being 
obtained by extracting the crushed seeds with volatile solvents, 
although most of the oil is still expressed. At times large quantities 
of soy beans, both domestic and imported, have been crushed for 
oil in the United States. Cottonseed-oil mills can handle soy beans 
with little or no change in their equipment. Some oil also is made 
in mills equipped with expellers. 
Grades 
The following grades of soy-bean oil have been established by the 
Interstate Cotton Seed Crushers' Association. 7 
Prime crude soy-bean oil. — Prime crude soy-bean oil shall be pressed and not 
extracted from soy beans, free from water and impurities, and when refined 
by the association's official methods, shall produce an oil of no deeper color 
than the two combined standard glasses of 35 yellow and 9 red, with a loss not 
exceeding 5 per cent ; provided that any oil that refines with a greater loss than 
5 per cent, but still makes prime refined oil with a color reading not exceeding 
35 yellow and 9 red, shall not be rejected, but shall be reduced in price by a 
corresponding per cent of the contract price of the oil. 
Crude soy-bean oil. — Crude soy-bean oil sold basis 7 per cent refining loss 
shall be pressed and not extracted, from soy-beans, and shall be free from 
Avater and impurities, and when refined as prescribed in the official methods 
of this association, shall produce an oil of no deeper color than the two com- 
bined standard glasses 35 yellow and 11 red, with a loss not exceeding 7 per 
cent; provided, that any oil that refines with a greater loss than 7 per cent, 
but still makes refined oil with a color reading not exceeding 35 yellow and 11 
red. shall not be rejected, but shall be reduced in price by a corresponding 
per cent of the contract price of the oil. 
Uses 
Belonging to the group of drying oils, soy-bean oil stands midway 
in its properties between linseed oil and the semidrying cottonseed oil. 
Consequently it can be used as a substitute for either of these two oils, 
especially in soap making. In the manufacture of soft soap, soy- 
bean oil serves as an almost complete substitute for linseed oil. In the 
manufacture of hard soap it can but partially replace cottonseed oil 
unless it is hydrogenated. It is extensively used as a substitute for 
part of the linseed oil in certain kinds of paint, as well as in the 
manufacture of linoleum. It is perfectly wholesome and in China 
and other Asiatic countries forms the staple food oil of large classes 
of people. When properly refined the oil loses its characteristic b£any 
flavor and can be used in the manufacture of lard substitutes, in 
margarine, arid even as a salad oil. 
CASTOR OIL 
Castor oil is obtained from the seeds of the castor-oil plant 
(Riciiws communis) , found in most tropical and subtropical regions, 
where it grows wild and is also cultivated. This plant varies greatly 
7 Interstate Cotton Seed Crushers' Association. Op. cit. p. 13. 
25059°— 27 3 
