Oct. 13, 1923 
Chemical Examination of “ Chufa” 
7i 
The petroleum extract was a pale yellow, inodorous, fatty oil, and the 
ether extract consisted of a fatty substance. The chloroform extract, 
which was very small in amount, was completely amorphous. The 
alcohol extract, after the removal of the solvent, formed a pale yellow, 
viscid sirup, having an agreeable, sweetish odor and taste. It readily 
reduced Fehling’s solution on heating, and evidently consisted chiefly 
of sugar. 
For the purpose of a more complete examination a larger quantity of 
material was subsequently employed. 
THE FATTY OIL 
Fifteen kgm. of the ground chufa were extracted as completely as 
possible with cold light petroleum (b. p. 35-55 0 C.). After the removal 
of the solvent, which was finally effected by heating on a steam bath in 
a current of carbon dioxid, the amount of fatty oil obtained was 4345 
gm., or 28.9 per cent. The yield of oil, as recorded in the literature, 
appears to be subject to considerable variation, which doubtless depends 
largely on the amount of moisture contained in the tubers, and also on 
the method of extraction. The smaller amount of material with which 
our preliminary experiments were conducted yielded by extraction with 
light petroleum 18.2 per cent of oil. 
Chufa oil has a pale yellow or reddish-yellow color and very little 
odor or taste. The characteristics of the product obtained by us were 
determined in the Oil, Fat, and Wax Laboratory of the Bureau of 
Chemistry by W. F. Baughman, and for this purpose the oil was deprived 
of the last traces of petroleum by heating it under diminished pressure 
at a temperature of 145-150° C. in a current of carbon dioxid. The 
following results were obtained: 
Specific gravity 2$°l2$° . o. 9120 
Refractive index at 20°. 1.468 
Iodin value (Hanus). 76. 6 
Saponification value. 1 9 1 • 5 
Acid value. 15* 7 
A complete chemical examination of the oil has now also been made 
by Baughman and Jamieson, the results of which are embodied in a 
separate communication to this number of the Journal of Agricultural 
Research (p. 77). 
EXTRACTION OF THE CHUFA WITH ALCOHOL 
ISOLATION OF SUCROSE 
Two kgm. of the material from which the fatty oil had been removed 
by means of light petroleum were completely extracted with hot alcohol. 
After the evaporation of the greater part of the solvent a reddish-yellow 
liquid was obtained from which a considerable quantity of crystals was 
soon deposited. These crystals, which evidently consisted of sucrose, 
were collected, dissolved in water, and an attempt made to extract the 
liquid with ether, but a jelly was thus formed and no separation could be 
effected. The ether was subsequently removed, and to the turbid 
aqueous liquid, which did not permit of filtration, a slight excess of a 
solution of basic lead acetate was added. A small amount of precipitate 
was thus produced, and the mixture acquired a pale reddish or fawn color. 
After filtration by suction, and the removal of the lead by hydrogen 
sulphid, a perfectly colorless liquid was obtained. This was extracted 
