14 
BULLETIN 1054, U. 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 51-inch 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 
After 
treat- 
ment 
bleaching 
with 
with 
fuller's 
caustic. 
earth. 
Red. 
Red. 
6.6 
3.5 
5.2 
4.0 
16.0 
10.0 
4.5 
1.6 
5.8 
3.6 
14.0 
8.0 
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. 
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 co?istants of the finished 
com oils. 
1 Specific 
gravity. 
Index 
of re- 
fraction. 
lodin 
number 
(Ha- 
nus). 
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 
