946 FOODS AND FOOD ADULTERANTS. 



that these substances are used to aid the opening (aufschliessen) of the 

 beans and not for the purpose of increasing the digestibility of the 

 preparation. 



The removal of the fat is not considered to be an adulteration when 

 it is acknowledged. It seems important, however, that the public have a 

 means of accurately knowing to what extent it has been removed. Con- 

 cerning the removal of the fat Mace ! writes : 



The most frequent adulteration of cocoa powder consists in depriving it of a part 

 of its fatty matter, cocoa butter. " The best means of detecting this is to estimate the 

 fat by means of ether. Cocoa thus adulterated has lost a great part of its nutritive 

 power, and manufacturers often make great claims for their fraudulent practice, pre- 

 tending to furnish a product which is more easily digested. 



The adulterants added are reported to be, besides sugar and starches, 

 other substances of organic and inorganic origin, to increase the weight 

 and bulk; ferruginous and other pigments to restore the color of highly 

 diluted preparations; and foreign fats to restore the normal percentage 

 of fat or to give the preparation the plasticity required for molding. 



As examples of the nature of adulterants reported, the following list 

 of H. W. Warren 2 may be cited : Sand, ferric oxide, clay, potassium 

 chromate, copper sulphate, and nickel sulphate are used as coloring 

 materials. Finely powdered tin is sometimes added to give the choco- 

 late a metallic luster. 



The husk, because of its coarse nature and consequent tendency to 

 act as an irritating substance in the alimentary canal, and in conse- 

 quence of its poverty in the constituents that render cocoa valuable, is 

 regarded as an adulterant when not removed or when added to increase 

 the weight or bulk of the preparation. 



MICROSCOPICAL EXAMINATION. 



For a thorough study of cocoa preparations, ;a microscopical exam- 

 ination is indispensable. An accurate knowledge of the structure of 

 the cocoa bean and of the substances used as adulterants is necessary 

 for the successful carrying out of this investigation. While this infor- 

 mation is only to be gained by actual study of the materials in ques- 

 tion, its acquirement is greatly facilitated by the use of descriptions and 

 illustrations. 



The literature of the subject will be found somewhat contradictory 

 (even with comparatively recent writers) in some details, but nothing 

 of importance in investigations for detection of adulteration seems to 

 be subject for debate at the present time. The works of Moeller and 

 Mace will be found to furnish valuable assistance in investigations of 

 this kind. The microscopical characteristics of the starches and other 

 materials used for adulteration have been so well described in various 

 works and in previous bulletins of this Department that any detailed 

 description of them seems unnecessary here. 



1 Mac6, Los substances alimentaires e'tudie'es an microscope. 

 Chem. News, 62, 99. 



