12 BULLETIN 666, U. S. DEPARTMENT OF AGRICULTURE. 
_ As might be expected, the ash of the soluble matter varies about 
the same as the ash of the cocoa. 
The water-soluble protein is slightly higher in the fies treated | 
cocoas than in the untreated cocoas, the maximum percentage 
being 0.51 higher, and the average 0.44 higher. ~The percentage of 
water-soluble protein insoluble in 1 per cent sulphuric acid, however, 
seems to be an important determination. In every case where the 
cocoa had been treated, more or less nitrogenous matter was precipi- 
tated by the addition of 1 per cent of sulphuric acid to the water- 
solution of the cocoa. This nitrogenous matter, calculated as pro- 
tein, ranged from 0.38 to 5.12 per cent. The total water-soluble pro- 
tein was not increased by any such figure. This would tend to show 
either that the alkah treatment inhibited the solution of some of the 
nitrogenous substances which would normally be dissolved by the 
water, or that'some substance was dissolved by the alkal, which on 
the addition of sulphuric acid had precipitated some of the protein 
which was normally water-soluble. The untreated cocoas showed 
no precipitate on the addition of 1 per cent of sulphuric acid, the 
only exceptions to this being samples 1, 13, and 29, which have 
already been set aside on the ground that they were more or less con- 
taminated with alkali-treated cocoas, having been made in a fac- 
tory which also makes alkali-treated cocoas and passed through the 
same machinery. In no case where the sample was made by a firm 
which makes no alkali-treated cocoa was there any precipitate. 
As might have been expected, the alkal treatment greatly en- 
hanced the color of the water solution. The color values of the 
untreated cocoas ranged from 20 to 39.3, with an average of 27.4, 
those of the treated cocoas from 25.5 to 98.4, with an average of 64.7. 
Only three of the alkali-treated cocoas showed a color value of less 
than 46.4, and 16 showed a color value of over 60. The maxi- 
mum of the alkali-treated cocoas was 59.1 above the maximum for 
the untreated cocoas, and the average was 37.3 above the average 
for the untreated cocoas. 
Samples 1 and 2, representing the same blend of cocoas, sample 1 
being untreated and sample 2 treated with 2.5 per cent potassium 
carbonate, show the effect of treatment. The total water-soluble 
matter, the water-soluble matter less the ash, the water-soluble pro- 
tein, and the color value are increased by the alkali treatment.. The 
nonnitrogenous, nonash soluble solids, however, are found in large 
amount in the untreated cocoa. Samples 15 and 11 represent the 
same blend of beans and the same alkali, but, in addition to the alkali, — 
sample 15 had added to it 10 per cent of water in the treatment. This 
water treatment largely increased the soluble matter and deependd 
the color. Sample 16 was made with 1.5 per cent potassium car-_ 
bonate and 1.5 per cent sodium carbonate, while sample 12 was made 
with 2.5 per cent potassium carbonate. The mixed carbonates in-— 
: 
