THE PRODUCTION OF CORN OIL. 15 
EFFECT OF COLOR AND CONDITION OF THE CORN ON THE YIELD AND 
CHARACTER OF THE OIL. 
Both white and yellow dent corn are used in this country for the 
manufacture of corn products, but the white seems to be generally 
preferred. In hominy mills the variety used is determined largely 
by the kind of corn meal demanded. Certain sections of the country 
consume only yellow corn products, while others prefer the white. 
Starch and glucose makers use both kinds, most operators claiming 
that the products are the same. There is no indication that there 
is any difference in the oil from the two kinds, but it is the opmion 
of some that the white corn has a larger germ and hence produces 
more oil to the bushel. This opinion is based largely on conjecture. 
The opinion seems to be quite general, especially among the dry- 
corn millers, that the quantity of oil obtainable decreases somewhat 
with the age of the corn. Their theory is that the oil ‘‘creeps”’ out 
cf the germ into the starchy portion of the kernel and is thus lost 
in the hominy products and feed. No definite study of this question 
seems to have been made. It is possible, however, that with age and 
the drying of the kernel the germ becomes more brittle and. thus 
chips and breaks more in the degerminators, the smaller fragments 
being lost in the feed. The monthly oil records for a number of 
years of one starch and glucose plant were carefully examined, and 
it was found that the quantity of oil in the corn, calculated on a 
moisture-free basis, was about 4.3 per cent, as determined by ex- 
traction with carbon tetrachlorid. The corn milled during the sum- 
mer months was somewhat higher in oil content. While the increase 
was only about 0.3 per cent, it was shown by the records that this 
increase occurred every year. Asarule, the corn used in the summer 
months is the last of the previous year’s crop. It would seem, 
therefore, that if the general assumption is true that the older corn 
yields less oil, it is not because there is less oil in the kernel, but 
because the degerminating is less efficiently performed on the older 
corn. In the dry process of degerminating, this is very likely to 
be the case. 
The condition of the corn with regard to its maturity has a pro- 
nounced effect upon the character of the oil and the quantity ob- 
tainable. According to figures available at one of the glucose plants, 
the soft corn of 1917 had a somewhat higher oil content than well- 
matured corn, but the general experience with that year’s crop 
showed a decidedly reduced yield. The explanation usually ad- 
vanced is that some of the oil was distributed in the kernel outside 
of the germ and was lost. A most interesting feature of this oil was 
its high acid content. While normally the oil averages between 
