THE PREPARATION OF CORN OIL. 



13 



It is quite evident that the maximum bleach is obtained within 

 the first hour of treatment. This is uniformly true at the three 

 temperatures used in this experiment. At 150° C. the oil darkened 

 during the first 15 minutes, increasing both in yellow and red, and 

 then started to bleach, reaching its maximum in 45 minutes. At the 

 higher temperatures the bleaching began at once and continued 

 rapidly during the first 15 minutes, reaching its maximum in 60 

 minutes in the sample maintained at 200° C. and in 45 minutes in 

 that at 300° C. The data included in figure 5 show that the bleach- 





4£ 60 7S 



T/ME /A/ M/A/urfS 



90 



Fig. 5.- 



-The extent of the bleaching effected by the deodorizing treatment continued for various periods 

 and at various temperatures. 



ing effect obtained at 200° C. was greatest, resulting in a very light 

 oil. The foregoing experiments justify the conclusion that corn oil 

 can be effectively deodorized and bleached by treatment with satu- 

 rated steam at 200° C. under a vacuum of 25 inches for one hour. 



Since the bleaching obtained was so apparent, two samples of oil 

 from the same source but not previously bleached with fuller's earth 

 were deodorized at 200° C. for two and four hours, respectively. 

 Table 7 shows the extent to which the oil was bleached and also a 

 comparison of the results with those obtained from treating the oil 

 with fuller's earth. 



67251°— Bull. 1010—22 3 



