14 
BULLETIX 1033, U. S. DEPARTMENT OF AGRICULTURE, 
The fats studied showed coefficients of digestibility ranging from 
91.5 to 97.1 per cent, except in blended cottonseed fat melting at 
50° C, which gave a coefficient of digestibility of 57 per cent. It is 
interesting to note that the blended fat with the highest melting 
point, namely, corn fat melting at 51° C, was 91.5 per cent di- 
gested, while straight hydrogenated peanut fat with a melting point 
of 52.4° C. was found to be only 79 per cent digested. 
A comparison between Table 10 and Table 11. adapted from the 
report 23 of earlier work with hydrogenated oils of the same origin 
as those used in blended form, gives an idea of the relative effect of 
the two methods of preparation upon digestibility. 
Table 11. — Summary of digestion experiments with hydrogenated regetaole oils 
in a simple diet. 
Num- 
ber of 
Kind of fat. 
Melting 
point of 
fat. 
lodin 
number. 
Digestibility of entire ration. 
Digesti- 
bility of 
experi- 
ments 
con- 
ducted. 
Protein. 
y t Carbo- 
* at - hydrate. 
hydro- 
genated 
vegetable 
oil alone. 
5 
Cottonseed 
°C. 
35 
38.6 
46 
37 
39 
43 
50 
52.4 
33 
43 
50 
S9.6 
Per cent. 
69.2 
69.5 
71.7 
69.1 
74.0 
73.8 
68.6 
55.9 
72.0 
76.3 
Per cent. Per cent. 
93.6 : 96.9 
92. 7 97. 3 
92.7 i 97.6 
95.0 96.9 
93.3 97.6 
93.5 ' 96.8 
88.1 1 97.6 
73.8 , 97.2 
91.7 97.4 
91.8 ! 97.0 
83.2 | 97.3 
Per cent. 
95.8 
1 
do 
95.5 
3 
do 
72.8 
81.3 
94.9 
Peanut 
9^.1 
3 
do 
95.9 
5 
do 
78.8 
58.5 
*'"\"89." 6' 
74.9 
55. 4 
96.5 
4 
do 
92.0 
3 
do 
Corn 
79.0 
94.7 
5 
do.. 
95.4 
do 
88.5 
The blended fats seem to be, as a rule, slightly better utilized than 
the straight hydrogenated oils melting at the same temperature. 
While no definite data are available regarding the cause of higher 
digestibility for blended fats, it is not without interest to suggest, 
as was done in an earlier paper, that in the process of digestion 
saponification may take place only on the exterior of the particles of 
hardened fat (i. e., for those melting at temperatures considerably 
above that of the human body), which decrease in size as the process 
of digestion continues. If surface area be thus a factor, then the rate 
of digestion and possibly the extent of digestion of a hydrogenated 
fat having a high melting point is governed to some extent by the 
size of the particles of hydrogenated fat ingested. If this hypothesis 
be tenable, it follows that particles of blended fat which are honey- 
combed with veins of a low melting fat would, after they had come to 
the temperature of the body, present greater surface area than par- 
ticles of straight hydrogenated oil, which present only an exterior 
surface to the action of the digestive juices. 
^Amer. Jour. Physiol., 54 (1921), No. 3, pp. 479-488. 
I 
