22 BULLETIN 904, U. S. DEPARTMENT OF AGRICULTURE. 
tank. (Fig. 11.) The treatment received in this tank is of great 
importance. Essentially this treatment consists of heating the 
oil to about 400° F. under vacuum by means of steam jackets 
and steam coils, superheated steam being used in these coils. Through 
a secondary coil with perforations, super- 
heated steam is passed into the oil. This 
treatment is continued for several hours, 
after which the steam is turned off and 
the oil allowed to cool under reduced 
pressure to normal temperature. The 
oil is thus further bleached, the peculiar 
odor and taste are removed, and a bland, 
tasteless, and odorless oil is produced 
which varies from a pale yellow to a 
very light straw color, according to the 
efficiency of the treatment. 
The process of deodorizing constitutes 
the most difficult part of the several proc- 
esses required to produce edible corn 
oil, and the details of the operation vary 
considerably in the several refining 
plants. Questions of temperature and 
time of treatment are determined largely 
by experimentation and the experience 
of the men in charge. The character of 
the crude oil used is also in some cases 
a determining factor. 
After the oil is cooled in the deodorizer 
it flows or is pumped into the storage 
tanks. While in storage it is in some 
cases kept at a low temperature in order 
See eras eae to effect the separation of stearin, which, 
structed with jacketed bottoms for however, does not separate from corn oil 
Se epee to the same extent as from some other 
vegetable oils. Finally, the oil is filtered through coarse paper or 
cloth to clarify and brighten it, especially when imtended for the 
retail trade. 
THE FUTURE OF CORN OIL. 
So far as can be concluded from the survey of the industry, corn 
oil appears to have established itself as a satisfactory product for 
which there will be a steady demand in the trade. That the oil can 
always be produced is assured by virtue of the fact that it is a by- 
product of the manufacture of certain staple corn products, and it is 
only in case of an overproduction of fats and oils that it might be 
discontinued and the germs disposed of as feed. Such a situation 
