12 



BULLETIN 350, U. S. DEPARTMENT OF AGRICULTURE. 



seen the favorable effect of the refining process. The acetyl value 

 of 20.3 in the crude pit oil was reduced to 3.45 in the refined oil. The 

 kernel oil, however, shows a considerably higher acetyl value than 

 the refined oil from the pits. This is due to the fact that the kernels 

 were taken from pits which were not in fresh condition. 



The amount of unsaponifiable matter in an oil depends largely 

 upon the amount of coloring matter and waxlike substances con- 

 tained in it. Therefore, the crude oil would be expected to show the 

 highest percentage, which is substantiated by the results obtained. 



As previously stated, the insoluble acids are most important fac- 

 tors in determining the quality and usefulness of an oil. Therefore, 

 the physical and chemical constants of these acids were determined, 

 and the results are presented in Table IV. For the purpose of com- 

 parison, the known constants of a number of related oils are also in- 

 cluded in Table IV. 



Table IV. — Physical and chemical constants of insoluble acids of oils from 

 cherry pits and kernels and from other fruit kernels. 



Source of oil. 



Color. 



Odor. 



Taste. 



Spe- 

 cific 



gravity 

 at25°C. 



Refrac- 

 tive 

 index 

 at25°C, 



Congeal- 

 ing point. 



Neu- 

 trali- 

 zation 

 value. 



Iod li 

 value. 



Cherry pits: 

 Crude 



Pale brown. 

 do 



Rancid, fatty. 



Slightly ran- 

 cid, fatty. 



Nutlike, slight- 

 ly rancid. 



Bland, fatty, 

 hitter. 



Sweetish,fatty, 

 hitter. 



Sweetish.fatty, 

 slightly hit- 

 ter. 



0. 9019 

 . 9137 

 .9092 



1.4635 

 1.4641 

 1.4635 



a 



12 to 11 

 12. 5 to 12 

 13.5 to 13 



13. 5 to 13 



192.4 



179.7 

 180.8 



205 



to 

 209.9 

 194 



200.4 



204 



99.9 

 93.7 



Cherry ker- 

 nels. 



Pale straw . . 



92.8 

 94.1 



nels. 1 



Apricot ker- 

 nels. 2 









.9195 





to 



101.9 

 99.4 











13 to 12 



11.8 

 to 

 11.3 



to 



103.8 

 95.7 



nels. 3 











1.4461 



to 

 102 

 93.5 



nels. 4 











to 

 96.5 



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

 1909. 



2 Specific gravity at 15° O, see Lewkowitsch, J., op. cit., p. 228. 



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



4 Refractivo index at 60° C, see Lewkowitsch, J., op. cit., p. 237. 



Only slight differences m the physical properties — color, odor, and 

 taste — of the insoluble acids are noted in the cherry oils. Data on 

 these points were not available for the other oils. The specific grav- 

 ity, refractive index, and congealing points of the insoluble acids of 

 cherry oils compare favorably with the same constants of the related 

 oils. The neutralization values differ somewhat from those of the 

 related oils, with the exception of the crude pit oil. This indicates a 

 slightly different composition from the standpoint of fatty acids. 

 The iodin value, which indicates the content of unsaturated acids, 



