8 
BULLETIN" 350, U. S. DEPARTMENT OF AGRICULTURE. 
with an efficient hydraulic press or oil expeller, a yield of at least 30 
per cent of oil should be obtained. 
For the purpose of comparing the yield and general characteristics 
of the oils obtained from cherry kernels by solvent and by expression 
with oils from related kernels, Table I was compiled. 
Table I. — Yield and physical properties of crude and refined cherry oils com- 
pared with other related oils. 
Source of oil. 
Yield 
of oil. 
Spe- 
cific 
gravity 
at 23° 
C. 
Index 
of re- 
fraction 
at 23° 
C. 
Congealing 
point. 
Color. 
Odor. 
Taste. 
Cherry pits (red 
sour cherries): 
Crude 
Refined 
Cherry kernels 
(red sour cher- 
ries) . 
Cherry pits(im- 
p or ted cher- 
ries) : 
Crude 
P.ct. 
8.3 
132 
4.5 
0. 9204 
.9171 
2.9150 
.9302 
.9276 
.9156 
4.9166 
* . 9168 
* . 9164 
* . 9162 
< . 9158 
1.4697 
1.4700 
1.4727 
1.45S2 
1.4790 
1.4775 
61.4712 
a 1.4705 
Turbid at —8° 
C; almost 
solid at —12° 
C. 
Turbid at —8° 
C; nearly 
solidat— 15° 
C. 
Turbid at -13° 
C; semisolid 
at— 18° C. 
Semisolid at 
-11° c. 
Semisolid at 
-16° C. 
do 
Solidifying 
point below 
-20° C.5 
-20°C.6 
-10° C? 
-21°C.8 
— 10°C.8 
Pale brown. . . 
Pale golden 
yellow. 
Pale golden . . . 
Peep brown... 
Pale brown 
Peep straw 
Yellowish 
Straw colored . 
Golden yellow. 
Light yellow . . 
Yellow 
Slightly rancid 
Bland, fatty... 
Pleasant, nut- 
like. 
Fatty, slightly 
rancid. 
Bland, fatty... 
Agreeable, 
fatty. 
Fatty, nearly 
odorless. 
Slightly fatty, 
nearly odor- 
less. 
Fatty, nutlike. 
Nearly odor- 
less, fattv. 
do...:.... 
Slightly acid, 
fatty .slightly 
bitter. 
Bland, fatty, 
nutlike. 
Bland, nutty, 
agreeable. 
Fatty, slightly 
acid. 
Bland, fattv. 
Cherry kernels 
(imported 
cherries). 
Peach kernels 3 . 
Apricot ker- 
nels. 3 
Prune kernels 3 . 
Sweet almonds 
(Spain). 3 
Bitter almonds 
(Italy). 3 
150 
39.5 
40 
35 
49 
42.3 
Fatty and nut- 
like. 
Bland, fatty, 
nutty. 
Fatty and nut- 
ty-' 
Bland, nutty, 
s 1 i g h t f y 
sweet. 
Nutlike and 
fatty. 
Bland and 
fatty. 
1 By ether extraction. 
2 Specific gravity and other physical constants represent expressed oil of cherry kernels. 
3 Rabak, Frank. Peach, apricot, and prune kernels as bv-products of the fruit industry of the r/nited 
States. U. S. Dept. Agr., Bur. Plant Indus. Bui. 133, p. 15", 1908. 
* At 25° C. 
5 Lewkowitsch, J. Chemical Technology and Analysis of Oils, Fats, and Waxes, v. 2, p. 232. London, 
1909. 
e At 20° C, see Lewkowitsch, J., op. cit., p. 228. 
"' Lewkowitsch, J., op. cit., p. 230. 
s Lewkowitsch, J., op. cit., p. 235. 
9 At 25° C, see Lewkowitsch, J., op. cit., p. 236. 
An examination of Table I shows that the specific gravity of the 
refined oil from the pits and of the expressed oil from the kernels 
corresponds very closely with that of the oils from the other kernels 
enumerated, thus indicating a like composition of all the oils, since 
the specific gravity of fixed oils is a property which is influenced 
largely by its composition. The high specific gravity of the crude 
pit oil is attributed to the presence of impurities, largely in the form 
of free fatty acids, which later were removed in the refining process. 
