COEX 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 acids in com oils after treatment toith 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° 0., at which tem- 

 perature it was held for 15 minutes. Then 5 per cent of standard fuller's 

 earth '" was added and the stirring continued for 10 minutes, at a temperature of 

 10."'- to llo C. The "il 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 tin- deodorizing: treatment. 



DEODORIZING. 



Tin- deodorizing of the oils was accomplished in half-liter lots in 

 gla - flasks by blowing with a current of dry steam ;i< 225 < '. (437° 

 V.) for two hour- under a vacuum of 25 inches. This treatment had 



ndard fuller'i earth i. recommended by the American Oil-Chemists' Society tor 

 bleaching regetable oil be obtained from the secretary of that Boclety. 



