10 



BULLETIN" 1054, U. S. DEPARTMENT OF AGRICULTURE. 



A serious difficulty encountered in the removal of the solvent was 

 the tendency of the oils to foam when the last portions of the benzol 

 were being removed. This foaming was much more severe in the 

 extracts from the dry-process germs, due possibly to the presence 

 of more starchy matter in such material than in the germ stock sepa- 

 rated by the wet process, in which all the starch is removed by thor- 

 ough washing. The presence of the starch also makes the benzol 

 extracts from the wet-process germs exceedingly difficult to filter. 



For purposes of convenience the several- oil's will hereafter be 

 designated as follows: A, Wet-process germ by expeller; B, wet- 

 process germ by solvent; C, wet-process cake by solvent; Z>, 

 dry-process germ by expeller; E, dry-process germ by solvent; 

 F, dry-process cake by solvent. 



APPEARANCE AND CHARACTER OF THE CRUDE OILS. 



Samples of the two expeller oils and the four benzol-extracted 

 oils were placed in standard 5J inch bottles for the purpose of com- 

 paring the color and other characteristics. Some of the oils, espe- 

 cially the benzol-extracted oils from the oil cake, appeared to be 

 somewhat turbid when cold, although they were filtered clear while 

 warm. For this reason the samples were allowed to stand in a dark 

 place for a month and their condition then noted. Table 3 sum- 

 marizes the appearance of the oils. 



Table 3.- 



-Colosr and appearance of crude com oils in standard 51-inch bottles 

 after standing in the dark for one month. 



Oils, a 



Color. 



Clarity, deposit of solids, etc. 



Sample D , dry-process germ by expeller. . 

 Sample E, dry-process germ by solvent... 

 Sample A, wet-process germ by expeller.. 



Sample B , wet-process germ by solvent . . 



Sample F, dry-process oil cake by solvent 

 Sample C, wet-process oil cake by solvent 



Bright golden Very slight whitish deposit. 



do ! About i-inch whitish deposit. 



Bright golden, with reddish Very slight whitish deposit. 



tinge. 

 Slightly more reddish than 



oil A. 

 Reddish veil ow 



About J-inch whitish deposit. 

 Hnch dark brown deposit. 



Reddish brown I J-mch light brown deposit. 



o The samples of oil are arranged according to their depth of color, lightest to darkest. 



It will be noted that the oils from the dry-process material are 

 on the whole somewhat lighter in color than the other oils. However, 

 the same oils also appear to have the heaviest deposits of solids. 

 While, no doubt, some stearin is present in these deposits, yet from 

 the fact that the oils from the dry -process germ material contain the 

 heaviest deposits it may be assumed that a portion of these solids is 

 starchy material. The benzol-extracted oils from the oil cakes deposit 

 by far the greatest quantity of solid matter. 



The free fatty acid content of each of the oils was determined, and 

 the results are shown in Table 4. 



