20 BULLETIN 666, U. S. DEPARTMENT OF AGRICULTURE. 
to a lesser degree, in a great number of the other cocoas. In some 
cases a cocoa which seems to be of a quite light color when dry shows 
a very high color in the water solution. The color developed in the 
cocoa depends, of course, somewhat on the blend of beans used, but 
to a greater extent on the treatment which the product undergoes. 
CONCLUSIONS. 
The greatest effect of the alkali treatment of cocoas is apparently 
the increase in the color of the water solution. The total water- 
soluble matter is increased but shghtly, and this increase is more than 
accounted for on the ground of the addition of the soluble alkali, the 
ash-free soluble matter being less in the case of an alkali-treated cocoa — 
than in the case of the untreated cocoas. There is a shght increase in 
the amount of water-soluble protein by the alkali treatment. This, — 
however, is more than made up for by the fact that the alkali treat- 
ment exercises an inhibitory action on the solution of the non- 
nitrogenous substances which are normally soluble in water. A 
portion of the water-soluble protein of the alkali-treated cocoas seems — 
to be different from that dissolved in the untreated cocoas, inasmuch — 
as it is rendered insoluble when the water solution is made 1 per cent — 
acid with sulphuric acid. This is a point of difference between alkali- 
treated and untreated cocoas which might well serve for the detection 
of the alkali treatment. 
As has been pointed out by other investigators, the alkali treat- 
ment increases the ratio of the soluble ash to the insoluble ash. This 
is true with all the alkalies employed, except ammonium carbonate 
and magnesium carbonate. Both of these, however, increase this 
ratio in the ash of the water-soluble matter, and this determination 
might serve as a clue to their presence. The ratio of the alkalinities ” 
of the ashes is still more pronounced than the ratio of the ash. The 
presence of an alkali-treated cocoa may therefore be proved by the 
high color value of the water solution, by the presence of a water- 
soluble protein precipitable in 1 per cent sulphuric acid, and by the 
increase in the ash ratios and the alkalinity ratios. 
This investigation proves that the claim that the alkah reac 
increases the amount of cocoa soluble in water is absolutely without 
foundation. 
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