/ 



CORN OILS. 11 



Table 4. — Percentage of free fatty acids in crude com oils. 



Oils. 



Percentage 



of free 

 fatty acids. 



Oils. 



Percentage 



of free 

 fatty acids. 



Sample A, wet-process germs by ex- 



1.76 

 2.15 

 3.60 



Sample D, dry-process germs by ex- 

 peller 



1.72 



Sample B, wet-process germs by sol- 



Sample E, dry-process germs by sol- 



1.90 



Sample C, wet-process oil cake by sol- 



Sample F, dry-process oil cake by sol- 



1.88 









It is of interest to note that the oils from the dry-process germs 

 (D, E. and F) are uniformly lower in free fatty acids than the oils 

 from the wet-process germs. There appears to be practically no 

 difference between the free acidity of the benzol-extracted oils and 

 the expeller oil of this group. In the case of the oils from the wet- 

 process germs (A, B, and C), the benzol-extracted oils contain more 

 free fatty acids than the expeller oil. This is especially true of the 

 oil extracted from the oil cake (C). 



REFINING 2 THE OILS. 



The six foregoing oils were refined as nearly alike as their indi- 

 vidual character would permit. The bleaching and deodorizing 

 were done in the same way in the case of each oil, but the method 

 of neutralizing with caustic required some modifications with cer- 

 tain of the oils. It was the intention to treat all as nearly alike as 

 possible, so that whatever differences might be noted in their quality 

 after refining could logically be assumed to be due to the inherent 

 differences in the oils obtained by the two methods of removal from 

 the germ. 



NEUTRALIZATION WITH CAUSTIC. 



After a number of preliminary experiments it was found that the 

 method of neutralizing the oils with caustic described in a previous 

 publication (Jf.'i) seemed likely to give the most generally satisfactory 

 results on the oils as a whole. After the preliminary experiment, 

 5-pound batches of oil were used in each case. The method used was 

 as follows : 



To ttx- ''.id <,ii there was added slowly, while stirring, sufficient 14° Be. 

 SOdliim hydroxid to neutralize the free fatty acids present plus 50 per cent 

 After being Btirred Cor in minutes the "ii was slowly beated while the 

 stirring was continued and the temperature raised to 55° 0., until the <>ii 

 broke. After the break ~ per cent of powdered soda :ish was added gradually 

 and the stirring continued for 5 minutes longer. The oil was then kept Cor 

 ?, hour:- :it 8 temperature of 50° O., after winch it. was allowed to cool over 

 night and then drawn off from the deposited soap stock. Channels were cut 



■ The term "refining" a« here used Include the tbree main operations usually em* 

 ployed in making edible oils: (1) Neutralization with caustic, (2) bleaching with 

 Caller's earth, and (3) deodorizing with steam, 



