COCOA BY-PRODUCTS 25 
If Xo. 109, the sample of pressed fines, and Xo. 103, which the ash 
and fiber results indicate is not a straight nibs cake, be excluded, it 
will be seen that the ammonia content of the samples on the dry, 
fat-free basis is fairly uniform, varying only from 5.86 to 6.40 per 
cent. 
The data on the quantities of the various forms of nitrogen have 
been calculated to the moisture-free, ether-extract-free basis also, 
and these values are shown in Table 3. 27 
The quantities of theobromine and caffeine found in the cocoa 
products examined (Tables 2, 4, and 5) are above the averages re- 
ported in the literature for powdered cocoas and cocoa shells by 
such recent investigators as Knapp (26) and Wadsworth (57). The 
use of special apparatus for continuous chloroform extraction of the 
samples while in aqueous suspension, made possible a very thorough 
extraction of the alkaloids. 
Although the theobromine and caffeine content, because of the 
toxicity of these bases, is of the greatest importance in relation to 
utilization of the cacao products as feedstuff's, the amount of these 
alkaloids present may also be significant if the material is to be 
used as fertilizer. Schreiner and Skinner (4-?, p. T®i 78) have inter- 
preted work by Lutz (31) indicating caffeine to be harmful in sand 
cultures to maize and species of Cucurbit a, and later experiments 
by Molliard (3 If) which showed both caffeine and theobromine to 
be harmful in water cultures to radishes. On the other hand, ricin 
(an active constituent of the castor bean) was found to be harmful 
to wheat seedlings in water cultures (41, p. 78) ; but the presence of 
this constituent does not appear to have been prejudicial to the 
general use of castor pomace as fertilizer material. 
The Kjeldahl method for the determination of nitrogen recovers 
as ammonia nearly 36 per cent of the weight of theobromine present 
(56) ; hence it is apparent that out of the total " ammonia " content 
of the cocoa products examined for theobromine plus caffeine 
(Tables 2, 4, and 5), from 0.96 to 1.14 per cent ammonia in the 
press cakes, 1.14 per cent in the sample of extracted cocoa examined, 
and 0.57 to 0.71 per cent in the shells, must be derived from the 
alkaloidal bases. To repeat, this ammonia probably is of no value, 
a ad, even in the soil, the alkaloids which it represents may be actu- 
ally injurious to growing plants. 
By determining the water-insoluble theobromine plus caffeine it 
was found, as noted previously, that practically all of the alkaloid 
is readily extracted from the cocoa products by water at room tem- 
perature. The alkaloid nitrogen is therefore included with the 
water-soluble nitrogen. Wadsworth's results on the solubility of 
theobromine (55) also show that the pure base is sufficiently soluble 
in water for the total amount present in any of the samples to 
have been dissolved under the conditions governing the determina- 
tion of water-soluble nitrogen, if the theobromine was present in 
the free or uncombined state. No attempt was made to determine 
whether the alkaloids were present in the free or combined state 
in the cocoa samples. 
The amounts of total alkaloid found, ranged from 2.7 to 3.2 per 
cent for the press cakes (omitting the sample on which only theo- 
27 In this connection it is of interest that a preliminary extraction with ether or petro- 
leum ether rendered actually more nitrogen soluble in water for several of the samples. 
