By an examination of the ash the presence of any mineral adulterant may be detected. Mr Blyth says the amounts of ash in genuine cocoa should never exceed 5 per cent. The seed of the cocoa consists of husk and seed proper. Under the microscope the husk exhibits on its surface a number of tubular
fibres, filled with granular matter and minute corpuscles. It consists of three membranes; the first being a single layer of elongated cells; the second (forming the chief portion of the husk) of angular cells, enclosing mucilage, and also containing a few spiral vessels and woody fibres. The third membrane is very thin and delicate, and is made up of small angular cells containing minute globules of fat. The seed is composed of minute cells containing starch. The starch corpuscles are very small, with a trace of inulin. (See cuts on previous page.)
Cocoa, Flake. This is formed by grinding the nibs in a mill, consisting of two cones, working one inside the other. Pure flake cocoa is not a diluted or amalgamated article; in other words, it contains no sugar, and but a trace of starch.
Cocoa Nibs. The bruised, roasted seeds, freed from husk and membrane. They ought to be of a dull-red or greyish colour, but are frequently given a bright-red colour by a coating of Venetian red.
Cocoa, Sol′uble. From cocoa nibs and substances which are readily soluble or diffusible in water, ground together. Sugar and sago or arrow-root are the diluents used by respectable makers, but all kinds of starches, coloured with Venetian red, are used for the trashy articles which are sold to the poor. No form of cocoa is really soluble, but by the addition of easily diffusible substances an article is produced which is capable of forming an emulsion with boiling water. The following are the principal varieties of the so-called soluble cocoa:—
1. Cocoa, Granulated. From cocoa nibs and sufficient sugar and arrow-root to keep the fatty particles from forming a pasty mass. As it is impossible to granulate the nibs without the admixture of some other substance, those makers who declare that their granulated cocoas are perfectly pure do not act honestly towards their customers.
2. Cocoa, Homœopathic. A kind of soluble cocoa prepared with arrow-root, but without sugar.
3. Cocoa, Iceland-moss. From cocoa and Iceland moss, freed from its bitter principle, cetrarine. This form of cocoa was introduced by Messrs Dunn and Hewett, and is said to form a very valuable article of diet for invalids.
4. Cocoa, Maravilla. This is stated to be “the perfection of prepared cocoa.” It consists of cocoa, sugar, and sago flour, the last two being in great excess.
5. Cocoa, Caraccas. This is similar to the last, being a mixture of cocoa, sugar, and sago flour. The cocoa used in its manufacture is said to be imported from the Caraccas, on the north coast of South America, and to possess a peculiarly delicious flavour.