16 BULLETIN 904, U. S. DEPARTMENT OF AGRICULTURE. 
1 and 2 per cent of free acids, the oil from the 1917 crop averaged 
nearly 10 per cent and in many instances was as high as 15 to 17 
per cent. It was also darker than usual and the expelling was more 
difficult, in some cases more than 15 per cent of the oil being left in 
the cake. Naturally the refining of this oil involved big losses, and 
consequently it brought a greatly reduced price in the crude state. 
-~COMPARISON OF THE OIL-PRODUCTION OPERATION IN DIFFERENT 
MILLS. 
In order to ascertain the extent to which the products from the 
various mills differed, determinations were made of the fat and mois- 
ture content of the germ, oil cake, and feed secured from these mills, 
and samples of the oils they produced were tested for free fatty 
acids. Table I shows the results. 
Tas Le I.—Comparison of the fat, moisture, and free fatty acid content of material produced 
in representative corn-producis mills in the United States, showing the results of the 
wet and dry processes of degerminating the kernels. 
Source of material, different mills (per cent). 
Material analyzed. | Averaze 
1 2 5 ee ee 5 6 7 of7 
mills . 
Sec. A.—Hominy mills (dry 
process): 
Free fatty acids— 
Grade oil. = 1.29] 0.78 0.7. 0.88 PANS Ae Oe. 0.88 | 1.11 
Refined oil. ...---=-- sri LT Peeps oe ees eee Ree ee SS Rea [a> eens ee 
Fat— | > 
Germs = ee [Se ees | ==1S23 | 14.37] 15.68) 22:41] 16.66] 24.90 17.88 
Oilicake <5 se eee | 5.80 AAO ee. es 7.90 9.38 | a 12.97 6.82 
Roed a | ernecs 6.36| 6.15 Ree ee 5.92 
Moisture— | 
Genises = oe eee eae Seep a oe 8. 66 7.90 8.49 9.61 4.31 6.96 
Oikeike =. ----=== [eee 3.37 1025541 7.96 4.45 2.74 5.81 
feed] a 1 12.50 10.35 12. 66 10.86 10:36:12 E 11.35 
Sec. B.—Starch and glucose | 
plants (wet process): 
Free fatty acids— | : } i : 
Crideols- f= 498-1: 89:17 1.39 1.65| 5.34 2.14 2.05 2.39 
Refined oil. .....-.--- |S eee | eee pe eae 11 A) Ss eee 
Fat— 
Germs 255.5 = | 51.85-| ¢23.78 41.99 22.35} 50.14 55.96 | 49.20 42.23 
Qilcake: +. se 8-9 8.08 7.35 9.25) a6.04 8.35} 10.30 8.70 
Reed es ee eee Eanes 6:85,| _ 3.63| 5.20-|- 2:85 |-273-26:| = = = 4.38. 
Moisture— 
Germs 5.55 eee 3.75 5.46 4.68 4.38 4.62| 2.28 5.44 4.37 
Oil cake 253 | 9.74 9.20 7.89 3.80 fA eee 8. 67 7.74 
Heed= 2.25 see 11.12 9.53 10.38 | 8.91 12 | 2S 10.15. 
a Not included in average. 6 Immature corn of 1917, not included in average. ¢ Immature corn of 1$17. 
A study of Table I shows that there is a wide variation in the 
character of the material produced in the various mills. While the 
percentage of free fatty acids in the oils is low it is evident that the 
oil obtained from germs separated by the dry process of degerminating 
is somewhat lower than that from the wet process. This might be 
expected from the nature of the two processes. So far as observation 
indicates, however, the refined oil from the two processes shows no 
noticeable difference. The percentages of fat in the germs and oil 
