in 



THE CHEMISTRY OF COCOA 31 



C 2 H 6 + 2 = C 2 H 4 Ojj + H 2 



Alcohol. Oxygen. Acetic acid. Water. 



This process takes place together with the develop- 

 ment of heat. In the fermenting-boxes the temperature 

 is usually allowed to rise to about 45 or 50 C. (113 or 

 122 F.). This temperature kills the protoplasm of the 

 kernel, and accordingly the different substances contained 

 in the seed are allowed to act upon each other ; a direct 

 and important influence of the acetic acid upon the 

 substance in the seed has not been demonstrated. Many 

 of the changes and chemical reactions in the seed during 

 fermenting and drying are still unknown. A large and 

 interesting field of investigation for the analyst is here 

 unexplored. 



Three of the important chemical reactions, which 

 have been more or less carefully studied, may now be 

 described : 



( 1 ) The formation of cocoa-red and theobromine. 

 The manner in which these substances originate is 

 not yet properly determined. It may be that it takes 

 place by oxidation of a glucosid, cacaonine, 1 but several 

 investigators (among them Ultee and van Dorssen) deny 

 or doubt the presence of a glucosid in the cocoa seeds. 

 Others accept the presence of the glucosid cacaonine, 

 which they presume to be split up and at the same time 

 combined with oxygen under the influence of an enzyme. 

 The result of this reaction would be theobromine and 

 cocoa-red, according to the equation : 



C 60 H 86 N 4 + 8H 2 + 200 2 - C r H 8 2 N 4 + 6C 6 H 12 6 + C 17 H 22 10 



Cacaonine. Water. Oxygen. Theobromine. Glucose. Cocoa-red. 



The theobromine is important, as it is the principal 

 substance which gives the cocoa its tonic properties. 

 The cocoa-red causes the reddish colour of the prepared 

 bean ; it was formerly regarded as important as giving 

 the cocoa its peculiar flavour. This however is not the 

 case, as cocoa-red is tasteless and flavourless. 



J Sack, "Bydragen tot de kennis van het fermenteeren der cacao" (Bulletin 

 No. 10 of the Dept. of Agriculture, Surinam). 



