10 BULLETIN 632, U. S. DEPARTMENT OP AGEICULTUEE. 



USES AND VALUE OF THE OIL. 



Classifying fatty oils as drying, semidrying, and nondrying, to- 

 mato-seed oil possibly falls into the semidrying class, bordering, 

 however, very nearly on the nondrying class. In order that the na- 

 ture of tomato-seed oil may be better understood, a comparison is 

 given in Table III of some of the more important properties of a 

 number of oils of commerce belonging in the same class "with tomato- 

 seed oil (10, v. 2). 



Table III.- 



-Physical and chemical properties of tomato-seed oil and several 

 important oils of commerce. 



Oils. 



Specific gravity 

 at 15° C. 



Congealing 

 point (°C). 



Saponification 

 value. 



Iodin value. 



Index of 

 refraction 

 at 20° C. 





0.922 to 0.930... 

 0.924 to 0.927... 

 0.9203 to 0.9260.. 

 0.9213 



Turbid at —2; 

 pale yellow 

 solid " mass 

 at -10. 



3to4 



188.6 



191 to 196. 5 

 190. 6 to 192. 9 

 187. 6 to 194. 6 

 188 to 193. 4 



114.2 



100. 9 to 116. 9 

 121 to 124 



103 to 115 

 112 to 130. 8 



6 1. 4715 



Cotton seed, Lewko- 



1.4722 



witsch (10, p. 149-150). 



+15 to+ 8.... 

 - 4 to- 6.... 

 -10 to -20 . . . 





(10, p. 123). 

 Sesame, Lewkowitsch 

 (10, p. 173). 



1.4723 

 c 1.4768 



p. 131-132). 







a At24°C. 



b At25°C. 



c At 15.5 °C. 



The similarity of tomato-seed oil to the commercial oils given in 

 Table III indicates the classification of this oil. The oils mentioned 

 in connection with tomato-seed oil are applied commercially in a 

 number of ways. As edible oils they are highly prized. On account 

 of their drying properties some are employed extensively in the 

 manufacture of paints and varnishes, while others find important 

 application as soap stock. 



Tomato-seed oil, with properties similar to cottonseed, soy-bean, 

 sesame, and corn oils, should be equally useful and applicable to the 

 same purposes as these oils of commerce. 



Experiments conducted with tomato-seed oil by Dr. A. D. Holmes, 

 of the Office of Home Economics, U. S. Department of Agriculture, 

 to determine its digestibility, showed that the oil possesses a coeffi- 

 cient of digestibility of 97, comparing favorably with olive, almond, 

 cottonseed, peanut, coconut, sesame, walnut, and brazil-nut oils. 

 Well-refined tomato-seed oil is therefore to be recommended for 

 culinary purposes. As a salad oil it should prove very satisfactory. 

 The edible quality of the oil suggests also its possible hydrogenation 

 and application as a margarine oil. 



An experiment to determine its saponifying properties was con- 

 ducted in order to obtain information regarding its possible use 

 as soap stock. By cold saponification with caustic soda and subse- 



