440 



SCIENTIFIC AND APPLIED PHARMACOGNOSY 



a small amount of tannin. The red color of the seed is due to a 

 principle known as cacao-red, which is formed by the action of a fer- 

 ment on a glucoside. 



Cocoa Shells. Little or no starch; oil globules; characteristic, 

 brownish, adhesive fragments, possessing more or less hexagonal 

 epidermal cells; peculiar, small, tabular mucilage cells and a layer 

 of nearly isodiametric stone cells. 







OO-Q 



FIG. 192. Cacao starch: A, starch grains of commercial cacao powder, or choco- 

 late, after removal of the oil by means of ether. B, altered starch grains 

 of cacao produced by making sections or scrapings of the raw cacao bean, 

 removing the oil with ether, mounting on a slide in water and heating at a 

 temperature of 70 C., for a few seconds; a, 6, c, d, successive stages in the 

 alteration of 2-, 3-, and 4-compound grains, the various masses showing 

 resemblance in size and form to the single grains of corn, wheat and even 

 potato starch as seen in some of the swollen masses (S). 



Adulterants. All chocolate products may be adulterated with 

 any of the cereal starches, those of corn, wheat and rice being usually 

 employed; Wasicky and Wimmer use a method for the detection of 

 shells in cocoa based on the difference in appearance between shell 

 and nib tissue when viewed through a microscope by ultra-violet 

 light. Amer. Jour. Pharm., 1918, 90, p. 215. 



Literature. Zwaluwenburg and Schlotterbeck, Proc. A. Ph. A., 

 1899,'p. 190. 



