COMMERCIAL PREPARATIONS OF THE COCOA BEAN. 941 



gives a green precipitate with ferric chloride, not unlike that given by caffeic acid 

 under similar treatment (Bell). 



Cocoa-red is not present in the fresh beans, but is the product of the oxidation of 

 the natural tannin of the seed. It consequently appears in different quantities in 

 different cocoas. It has the characters of a resin and exhibits variable degrees of 

 solubility, probably coinciding with the extent of oxidation \vhich it has under- 

 gone. 



Bell 1 reports 2.20 per cent of cocoa red in raw beans; Muter, 3.96 per 

 cent. 



Gum. It is precipitated from the aqueous solution of the fat-free 

 beans by alcohol. After drying it resembles gum arabic; by treatment 

 with nitric acid, yields mucic acid; and, when ignited, leaves an ash con- 

 sisting of basic phosphate of magnesium. Its specific rotatory power 

 is [a] j = + 68.6 (Boussingault 2 ). 



The beans contain 2.17 per cent of gum according to an analysis by 

 Bell, 1 and 2.5 per cent according to Boussingault. 2 



Tartaric acid. Weigmann 3 estimates tartaric acid by precipitation 

 of the aqueous extract, after neutralization with ammonia, with calcium 

 chloride, redissolving in hydrochloric acid and reprecipitating with 

 sodium hydrate. The amount of tartaric acid is calculated from the 

 amount of calcium oxide contained in this precipitate. By this method 

 he found 4.34 per cent to 5.82 per cent of tartaric acid in the raw, 

 whole beans. Boussingault 2 reports 3.4 per cent and 3.7 per cent. 



The aroma of cocoa is considered to be due to the presence of minute 

 quantities of an aromatic volatile oil. Boussiugault 2 proves its pres- 

 ence by distillation of the roasted grains with water. 



THE COMMERCIAL PREPARATIONS OF THE COCOA BEAN, THEIR 

 NATURE, METHODS OF PREPARATION, AND ADULTERATION. 



The preparations of cocoa are so numerous that more or less confu- 

 sion of terms naturally arises. Most American manufacturers prepare 

 a plain chocolate (known in Europe as cacao-masse), made by reducing 

 the roasted and husked beans to a paste and pressing into the form 

 of cakes. When this is combined with much or little sugar (generally 

 much), vanilla and spices, the various "sweet," "vanilla sweet," 

 " vanilla, " " spiced," etc., chocolates are produced. These are also usually 

 met in the form of cakes, but are sometimes pulverized and sold as "pow- 

 dered chocolates." The high percentage of fat renders a permanent pow- 

 der impossible without its partial removal or the addition of some 

 diluent, as sugar, starch, or flour. The preparations in powder, known 

 as "cocoas," "bromas," etc., are prepared in accordance with one or 

 the other, or a combination of these methods. 



1 Op. cit., note 1, p. 939 of this work. 



2 Ann. Chim. Phys. [5], 28, 433; Jour. Chem. Soc., 1884,46, 202; Chem. Ztg., 1883, 203 

 and 902. 



3 Op. cit., note 8, p. 938 of this work. 



