8 BULLETIN 632,-U. S. DEPARTMENT OF AGRICULTURE. 













acids were present. These insoluble acids were separated into the 
solid and liquid acids by means of the lead-ether method (17, p. 45). 
The mixed acids were found to consist of solid acids 17.54 per cent 
and liquid acids 75.84 per cent. 
The physical and chemical properties of the insoluble acids and the 
solid and liquid acids, were determined with the results shown ir 
Table IT. 
TABLE II.—Physical and chemical properties of insoluble, solid, and liquid acids 
of tomato-seed oil. 

Physical and chemical | 


properties. Insoluble acids. Solid acids. Liquid acids. 
| | 
Colorsee2 3 Santee Seen | Pale golden yellow; | Snowy white, flaky..... Pale golden yellow. 
| partly solid. 
Odor. a0 Fee eeors eee SR athy, RULIKC 28 se eee ea thy se ees eee & Pleasant, nutlike. 
ok MNS AS Se ak a Sweetish, fatty.......... Patty. tallowlike........ Sweetish, nutlike, be- 
coming slightly bitter. 
specific prayity al Jo 10 2 OF9IO0 lois ee ole cee ie ee eee eee 0.9013. 
Index of roiraction Mat. |:1465bsay. (os eh ela eng Se ee er ee 1.4654. 
Congealing point.. ae / +21.5° C. to +20.5° C...| Melting point, 53.5° C. 
Neutralization value.. ee oe Geer eer ane eee eae Nears DAs ee aoe tee ae ee 192.3 
Hodiripyalie sok Los NEES areas eee ee ee nl ape Si oe CR 130. 


The solid acids, comprising 17.54 per cent of the oil, probably 
consist largely of palmitic and stearic acids with neutralization 
values of 219.1 and 197.5, respectively. The neutralization value 
204 would indicate a mixture of these two acids. Although the melt- 
ing point of crude solid acids is considerably lower than either 
palmitic or stearic acids, which melt when pure at 62° C. and 69° C., 
respectively, it is very probable that this is due to the presence of 
impurities. 
Calculating from the neutralization value 204, the mean molec- 
ular weight of the solid acids wus found to be 275. This indicates 
the presence of palmitic and stearic acids, since the molecular weight ® 
of these acids are 256 and 284, respectively. 
In order to ascertain the approximate proportions of these two — 
acids in the mixed solid acids, a calculation was made according 
to the method suggested by Lewkowitsch (10, v. 1, p. 515), using as 
a basis 275, the mean molecular weight of these solid acids. By 
this method, the percentage of palmitic acid was found to be 67.8 
and of stearic acid 32.2. 
Since 17.54 per cent of the original oil consists of solid acids, the 
oil therefore contains palmitic acid 11.88 per cent and stearic acid — 
5.64 per cent. Because the palmitic and stearic acids exist in the o1 
as palmitin and stearin, it is necessary to reduce the above figures 
to terms of these glycerids. The glycerid palmitin contains 95.29 
per cent of palmitic acid, and the glycerid stearin contains 95.73 — 
per cent of stearic acid. By calculation, therefore, it is found that — 
