CORN OILS. 
13 
extracts of the oils from dry-process germs and retard their filtering 
are accountable for the greater refining losses in such oils. In the 
case of the extracted oils from the cake the same condition exists, 
and a lower refining loss was experienced with oil C than with oil F, 
although the former contained practically twice as much free fatty 
acids. 
The free fatty-acid contents of the oils after treatment with caustic 
are given in Table 6. 
Table 6. — Quantity of free fatty adds in com oils after treatment ivith caustic. 
Oils. 
Free fatty 
acids. 
Oils. 
Free fatty 
acids. 
Sample A, wet-process germs by expeller . 
Sample B, wet-process germs by solvent. 
Sample C, wet-process oil cake by solvent. 
Per cent. 
0.039 
.050 
.058 
Sample D, dry-process germs by expeller. 
Sample E, dry-process germs by solvent. 
Sample F, dry-process oil cake by solvent . 
Per cent. 
0.033 
.053 
.066 
It will be noted that after the treatment with caustic the oil con- 
tained only a very slight percentage of free fatty acids. The color 
of all the oils made directly from the germs was quite satisfactory, 
and oils prepared by benzol extraction did not show to disadvantage 
as compared with the expeller oils. The oils extracted from the oil 
cake were, of course, considerably darker than the others, the same 
general color relationship being evident as that which existed in the 
crude oils. The color of the oils after the treatment, as read on the 
Lovibond scale, is included in Table 7 for the purpose of comparison 
with that from the finished oils. 
BLEACHING WITH FULLER' S EARTH. 
All the oils were treated exactly alike during the process of bleach- 
ing with fuller's earth. The procedure used was as follows : 
The oil was heated slowly, with constant stirring, to 110° C, at which tem- 
perature it was held for 15 minutes. Then 5 per cent of standard fuller's 
earth 3 was added and the stirring continued for 10 minutes, at a temperature of 
105° to 110° C. The oil was then rapidly filtered on a force filter. 
The effect of this treatment on the color of the oils is shown in 
Table 7 in connection with the discussion of the bleaching effect 
of the deodorizing treatment. 
DEODORIZING. 
The deodorizing of the oils was accomplished in half-liter lots in 
glass flasks by blowing with a current of dry steam at 225° C. (437° 
F.) for two hours under a vacuum of 25 inches. This treatment had 
8 Standard fuller's earth is recommended by the American Oil-Chemists' Society for 
bleaching vegetable oils and may be obtained from the secretary of that society. 
