COCOA. 



3 



correct, while those of Tuchen and Muter are the least so. We thus 

 see that, taking the most important constituents, cocoa contains : 



Parts. 



Cocoa butter 50 



Albuminoid substances 20 



Starch, sugar, &c 13 



Salts 4 



Theobromine 2 



Other substances 11 



100 



Examining these in the order of their importance, we first notice 

 the fat, or cocoa butter, which forms about half the substance of the 

 nibs. It is a hard, fatty material, which, when clarified, is of a dead 

 white colour. Its melting point is about 100° Fahr., which, being the 

 heat of the body, renders it of great value for therapeutical purposes. 

 This fat never becomes rancid, however long it may be kept, a quality 

 peculiar to itself. It is hardly necessary to point out how valuable 

 this property is, for it places cocoa butter first in the list of the fatty 

 class of our carbonaceous or heat-giving foods. The albuminoid con- 

 stituents form about 20 per cent, of the nib. These are classed 

 amongst the nitrogenous principles of food, and their presence 

 renders cocoa one of the richest flesh-formers we have. The starch, 

 gum, and sugar present, like the cocoa butter, belong to the non- 

 azotised principles; they form about 13 per cent, of the whole. 

 The alkaloid of cocoa, theobromine, is very similar in its physiolo- 

 gical effects to its analogues, tJieine and cajfeine, from which it differs 

 but slightly in chemical composition. 



Essential Alkaloid Peinciples. 



Yielded by 



Name, 



Composition. 



Proportion. 





Theobromine 



0, H3 N, 0, 



2 per cent. 



Coffee 



Caffeine 





Tea 



Theine 



1 All identical 



|l to 5 per cent. 





Guaranine 



1 C3 H,oN, 0, 





Theine 



In less quantities. 



In regard to these alkaloids, it is interesting to note that through- 

 out the world the instinct of man has led him to seek some substance 

 that contains one of these principles, which owe their value to the 

 specific influence they exert on the nervous system, stimulating it and 

 checking waste of tissue. Theobromine, when extracted, presents the 

 form of a white crystalline powder of almost amorphous character, 

 differing from caffeine and ifeeme, which have a very beautiful crystal- 

 line appearance. 



In most of the analyses of cocoa the existence of a volatile oil has 

 been overlooked. It is probably present only in small quantities, 

 and appears to be developed by roasting ; but upon it depends the 

 flavour and aroma which exist in cOcoa.* 



* Mr. John Holm " On Cocoa and its Manufacture," * Journal of the Society of 

 Arts,' vol. xxii. p. 356. 1874. 



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