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 which it has under- 
gone. 
Bell! reports 2.20 per cent of cocoa red in raw beans; Muter, 3.96 per 
cent. 
Gum.—lIt 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 mucie acid; and, when ignited, leaves an ash con- 
sisting of basic phosphate of magnesium. Its specific rotatory power 
is [a] j] = + 68.6 (Boussingault’). 
The beans contain 2.17 per cent of gum according to an analysis by 
Bell,'! and 2.5 per cent according to Boussingault. ” 
Tartaric acid—W eigmann® 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? reports 5.4 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. Boussingault’ 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 
metin 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. 
! 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. 
