8 



BULLETIN 350, IT. 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 



P.ct. 

 8.3 



Refined. 



Cherry kernels 

 (red sour cher- 

 ries). 



Cherry pits(im- 

 ported cher- 

 ries): 

 Crude 



Refined 



Cherry kernels 

 (imported 

 cherries). 



Peach kernels 3 . 



Apricot 

 nels. 3 



ker- 



Prune kernels 3 



Sweet almonds 



(Spain), s 

 Bitter almonds 



(Italy). 3 



'32 



4.5 



150 

 39.5 

 40 



49 

 42.3 



0. 9204 



2 . 9150 



9302 

 9276 

 9156 



9166 



1.4582 

 1.4790 

 1.4775 



H.4712 



9162 

 9158 



Turbid at —8° 

 C; almost 

 solid at — 12° 

 C. 



Turbid at— 8" 

 C; nearly 

 solid at— 15° 

 C. 



Turbid at -13' 

 C; semisolid 

 at-18°C. 



Semisolid at 



-11° C. 

 Semisolid at 



-16° C. 

 do 



Solidifying 

 point below 

 -20° C.s 



-20°C.e 



-10°C 7 



-21°C 3 



-10°C.s 



Pale brown. . 



Pale golden 

 yellow. 



Pale golden . . 



Peep brown. 

 Pale brown. . 

 Deep 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, fatty. 

 do 



Slightly acid, 

 fatty ^lightly 

 bitter. 



Bland, fatty, 

 nutlike. 



Bland, nutty, 

 agreeable. 



Fatty, slightly 



acid. 

 Bland, fatty. 



Fatty and nut- 

 like. 



Bland, fatty, 

 nutty. 



Fatty and nut- 

 ty- 



Bland, nutty, 



slightly 



sweet. 

 N u 1 1 i k e 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 by-products of the fruit industry of the United 

 States. U. S. Dept. Agr., Bur. Plant Indus. Bui. 133, p. 15, 1908. 



4 At 25° C. 



6 Lewkowitsch, J. Chemical Technology and Analysis of Oils, Fats, and Waxes, v. 2, p. 232. London, 

 1909. 

 6 At 20° O, see Lewkowitsch, J., op. cit., p. 228. 

 ' Lewkowitsch, J., op. cit., p. 230. 

 s Lewkowitsch, J., op. cit., p. 235. 

 9 At 25° O, 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. 



