EFFECT OF ALKALI TREATMENT ON COCOAS. 19 



16, combines to some extent the action of each, inasmuch as i he lolal 

 soluble matter is high and the soluble protein is high. The ash- and 

 protein-free solids are, however, rather low, as compared with those 

 in which sodium carbonate alone was used, thus seeming to indicate 

 that potassium carbonate has an. inhibitory action on the solution 

 of these solids. Sample 50, in which magnesium carbonate was used , 

 shows the lowest total water-soluble matter. This is partly due to 

 the fact that no soluble alkali is added, as the ash-free solid matter 

 is nearer to the average of the cocoas. 



There seems to be no definite relation between the amounts of 

 water-soluble protein insoluble in 1 per cent sulphuric acid and 

 the alkali used. This figure varies somewhat with the percentage of 

 alkali, although by no means in proportion. The color value of the 

 solution also shows a very wide range, and seemingly follows no defi- 

 nite rule, except that the use of sodium carbonate gives the highest 

 values. 



It is interesting to note that three of the four imported cocoas show 

 a total soluble matter and an ash-free soluble matter greater than the 

 maximum of the domestic treated cocoa, and two of them show a 

 greater ash- and protein-free soluble matter ; also three show a higher 

 percentage of soluble protein than the maximum of the domestic 

 products, and all four show a higher color value than the maximum. 

 With one exception, the total ash of these products is not appreciably 

 greater than that of the domestic products, and the ash of the water- 

 soluble matter falls well within the limits of the domestic products. 

 Tins indicates that the increase in the other constituents is not the 

 result of the addition of a larger amount of an alkali, such as sodium 

 carbonate, but that the difference lies largely in the treatment which 

 the cocoa undergoes. 



APPEARANCE OF THE COCOAS. 



The color of the dry cocoa in the samples examined varied widely, 

 from a light brown to a deep reddish purple. Some of the untreated 

 cocoas had a color nearly as pronounced as those that were treated. 

 This color is not necessarily the result of any blend of beans, but 

 depends largely on the treatment, especially the degree and rapidity 

 of heating and cooling which the cocoa undergoes in its manufacture. 

 The color of the dry cocoa seems to have but little connection with 

 the color of the water solution. For instance, sample 27, a cocoa 

 treated by a fermentation process, is among the darkest in the dry 

 state, but the water solution of this is of a very fight straw color, as 

 may be noted by the fact that the color value of a 4 per cent solution 

 in a i-inch cell was only 8.8. This is the most striking example of 

 the fact that the color of the dry cocoa and that of the water solution 

 bear little or no relation to each other. The same thing was noted, 



