THE PREPARATION OF CORN OIL. 



17 



free fatty acids, plus 50 per cent excess, was added gradually and 

 the mixture stirred for 30 minutes. After the temperature had risen 

 gradually over a period of 15 minutes to 55° C. and the break 

 had taken place, 2 per cent of soda ash was added and the stirring 

 continued for five minutes. After warming for three hours and 

 cooling overnight, the oil, which will be designated D, was drawn 

 off in the manner described for oil C. The refining loss was 7.35 

 per cent. The soapstock was firm but contained considerable 

 oil. After several holes had been cut in this soapstock with channels 

 draining toward them, the bucket was placed on a steam bath for 

 about 15 minutes. The holes quickly filled up with the oil, which was 

 then drawn off. Several times these holes filled up, and by this 

 means sufficient oil was recovered to reduce the refining loss to 

 5.44 per cent. 



The neutralized oil, although somewhat turbid, contained no soap 

 and consequently did not require washing. In this respect method 

 2 appears to have a distinct advantage over method 1. 



BLEACHING. 



Both oils were treated exactly alike from this point on. They 

 were first dehydrated at 110° C, with constant stirring for 10 minutes. 

 Five per cent of standard fuller's earth was then added and the stir- 

 ring continued for 15 minutes with the temperature at about 105° C. 

 The oils were then filtered rapidly through a Buchner funnel. 



DEODORIZING. 



Since there was at hand no apparatus large enough to deodorize 

 the large quantities of oils C and D, smaller quantities of each were 

 used. In each case the oil was treated at both 200° and 225° C. 

 (392° and 437° F.) in glass flasks for one hour under a vacuum of 25 

 inches. A comparison of the finished oils is given in Table 9. 



Table 9. — Comparison of oils C and D after finished treatment. 





Color (5|-inch cell). 



Free 

 fatty 

 acids 

 after 

 deodor- 

 izing at 

 200° C. 





Oils and 

 methods. 



After treat- 

 ment with 

 caustic. 



After 

 bleaching. 



After deodorizing at— 



General quality of finished 

 oils. 



200° C. 



225° C. 





Yel- 

 low. 



Red. 



Yel- 

 low. 



Red. 



Yel- 

 low. 



Red. 



Yel- 

 low. 



Red. 





Oil C, method 



1. 

 Oil D, method 



2. 



35 

 35 



5.2 

 5.6 



35 



35 



2.8 

 3.3 



20 

 16 



1.8 

 2.0 



13 



16 



1.5 



2.0 



Per cent. 

 0.092 



0.083 



I Odorless; no cereal taste; 

 > comparable to best com- 

 mercial sample. 



