THE PREPARATION OF CORN OIL. 



15 



The deodorization of these oils was extended over a long period, 

 in order to determine just what effect such a protracted treatment 

 would have. The oils were allowed to cool at 2 -hour intervals, so 

 that small samples might be removed to determine the color and free 

 acidity. The process was then continued for another period, and so 

 on. Table 8 shows the effect of the process of deodorization on the 

 formation of free acids. 



Table 8. — Percentage of free fatty acids in corn oil from dry and wet process germs after 



various treatments. 





Sample. 





Crude. 



Alkali 



treated. 



Deodorized — 





Two 

 hours. 



Four 

 hours. 



Six 

 hours. 



Eight 

 hours. 



Oil A 

 OilB 





percent.. 

 do.... 



0.92 

 2.17 



0.019 

 .022 



0.024 

 .032 



0.02 

 .04 



0.042 

 .051 



0.047 

 .056 



The diluted oils showed at all four stages of the deodorization treat- 

 ment very slight reactions for aldehydes with the Kreis reagent. 



Hounr Deooor/zeo 



Fig. 6.— The comparative bleaching of oils A and B by the deodorizing treatment during successive 2-hour 



periods. 



The marked effect of the deodorization treatment on the color of 

 the oils is shown graphically in figure 6. The results obtained are 

 further evidence that the bleaching is effected in the early stage of 

 the process. Though oil B was considerably darker than oil A before 

 they were deodorized, the finished oils after eight hours of treatment 



