14 



BULLETIN 1054, TJ. S. DEPARTMENT OF AGRICULTURE. 



a noticeable bleaching effect on all the oils. In order to show the 

 relative bleaching effected in the several oils by this and the other 

 processes the color readings are summarized in Table 7. 



Table 7. — Color readings of corn oils in standard 5\-imch bottles with the Lovi- 

 bond scale after treatment with caustic, bleaching with fuller's earth, and 

 deodorizing. 



Oils. 



Color (35 yellow in each case) . 



After 

 treat- 

 ment 

 with 

 caustic. 



After 



bleaching 



with 



fuller's 



earth. 



After 

 deodor- 

 izing. 



Sample A, wet-process germs by expeller . 

 Sample B, wet-process germs by solvent. . 

 Sample C, wet-process oil cake by solvent. 

 Sample D, dry-process germs by expeller. 

 Sample E, dry-process germs by solvent . . 

 Sample F, dry-process oil cake by solvent 



Red. 

 6.6 

 5.2 



16.0 

 4.5 

 5.8 



14.0 



Red. 

 3.5 

 4.0 

 10.0 

 1.6 

 3.6 

 8.0 



Red. 

 3.0 

 3.5 

 10.2 

 1.5 

 2.2 

 5.6 



It is of interest to note that the benzol-extracted oils from the germs 

 contained only slightly more red than the expeller oils. On the whole 

 the oils from wet-process germs are darker than those from dry- 

 process germs. The oils extracted from the oil cakes are naturally 

 considerably darker than the others, that from the dry-process cake 

 bleached much more than that from the wet-process cake ; in fact, the 

 latter oil is the only one in the entire group in which the color would 

 be likely to interfere to any extent with its use as an edible oil. 



COMPARISON OF THE FINISHED OILS. 



PHYSICAL AND CHEMICAL CONSTANTS. 



In order to show whether the six oils under discussion differed to 

 any extent as regards the usual physical and chemical constants, 

 these constants were determined and the results summarized in 

 Table 8. 



Table 8. — Comparison of some physical and chemical constants of the finished 



corn oils. 





Specific 

 gravity. 



Index 

 of re- 

 fraction. 



Iodin 

 number 

 (Ha- 

 rms). 



Acid 

 num- 

 ber. 



Saponi- 

 fication 

 num- 

 ber. 



Acetyl 

 num- 

 ' ber. 



Acids. 



Oils. 



In- 

 soluble 

 Hehner 

 num- 

 ber. 



Liquid. 



Solid. 



Reich- 



ert- 

 Meisel 

 num- 

 ber. 



Solidi- 

 fying 

 point 

 of the 

 mixed 

 acids. 



Sample A. 

 Sample B. 

 Sample C . 

 Sample D. 

 Sample E. 

 Sample F. 



At 25° C. 

 0. 9181 

 .9186 

 .9185 

 .9177 

 .9165 

 .9179 



At 25" C. 

 1. 4723 

 1. 4726 

 1. 4733 

 1.4726 

 1.4732 

 1. 4731 



122.8 

 121.6 

 123.0 

 124.8 

 121.2 

 125.5 



0.078 

 .10 

 .116 

 .066 

 .106 

 .123 



191.7 

 189.6 

 183.0 

 187.2 

 194.2 

 197.5 



9.26 

 9.81 



10.93 

 7.26 

 9.99 



10.58 



95.07 

 95.04 

 92.60 

 95.06 

 93.00 

 92.40 



Per ct. 

 91.27 

 91.10 

 89.96 



89.82 

 89.88 

 89.61 



Per ct. 

 9.73 

 9.90 

 10.04 

 10.18 

 10.12 

 10.39 



0.352 

 .312 

 .378 

 .115 

 .190 

 .135 



° C. 

 16.6 

 16.8 

 16.5 

 16.0 

 16.3 

 16.5 



