Page:Encyclopædia Britannica, Ninth Edition, v. 6.djvu/122

Rh 102 COCOA Haw cocoas are distinguished iu commerce by the name of the localities of their growth ; and it is foun d that the produce of particular regions maintains, pretty constantly, a distinctive character and appearance. The most esteemed of all varieties is that obtained from Venezuela, known in commerce as Caracas cocoa, next to which in value stand the red &quot; nuts &quot; of Trinidad. The finest qualities are in form and size not unlike thick round almonds ; they have a husk of a clear brick-red colour, and the cotyledons, which are of a deep chocolate brown, have a fine membrane permeating their entire substance, and dividing them into numerous irregular segments, into which the seeds are easily broken down. The kernels are astringent in taste, with a mild, not disagreeable ilavour. In chemical composition, as well as in physical characteristics, they vary within certain limits ; but the analysis by Payen may be taken as representing their average constitution. It is as follows : Fat (Cocoa Butter) 52-00 Nitrogenous compounds 20 00 Starch lO OO Cellulose 2 00 Tlieobromiue 2 - 00 Saline substances 4 00 Water 10 00 Cocoa red. . ), Essential oil .. ... trace3 100-00 The constituent upon which the peculiar value of cocoa depends is the theobromine, an alkaloid substance which till recently was supposed to be distinct from, though closely allied to, the theino of tea and coffee. It is now, however, known that the alkaloid in these and in two or three ether substances similarly used is identical, and their physiological value is consequently the same. The fat or cocoa butter is a firm, solid, white substance at ordinary temperatures, having an agreeable taste and odour, and very remarkable for its freedom from any tendency to become rancid. It consists essentially of stearin with a little olein, and is used in surgical practice, and in France as a material for soap and pomade manufacture. Tho starch grains present in raw cocoa are small in size, and of a character so peculiar that there is no difficulty in distin guishing them under the microscope from any other starch granules. As an article of food cocoa differs essentially from both tea and coffee. While only an infusion of these substances is used, leaving a large proportion of their total weight unconsumed, the entire substance of the cocoa seeds is prepared as an emulsion for drinking, and the whole is thus utilized within the system. While the contents of a cup of tea or coffee can thus only be regarded as stimulant in its effect, and almost entirely destitute of essential nutritive properties, a cup of prepared cocoa is really a most nourish ing article of diet, as, in addition to the value of the theobromine it contains, it introduces into the system no inconsiderable proportion of valuable nitrogenous and oleaginous elements. The manufacturing processes through which raw cocoa passes have for their object the development of the aroma peculiar to the substance, and its preparation in a soluble palatable and digestible form. The first operation consists in roasting the seeds, whereby the empyreumatic aromatic substance is formed, and the starch particles are changed into dextrin. The roasting is accomplished in large revolving cylinders, after the completion of which the roasted seeds are taken to the crushing and winnowing machine. Here the seeds are reduced to the form of nibs which are separated from the shells or husks by the action of a powerful f.iu blast. The nibs are next subjected to a process of winnowing in small quantities in hand sieves, by which the hard cocoa &quot;germs&quot; are sifted out, and mouldy or discoloured fragments are at the same time removed by hand. Nibs so prepared constitute the simplest and purest preparation in which manufactured cocoa is sold ; but they require prolonged boiling to effect their complete disintegration. The nibs when ground to a fine meal can be cooked with much greater facility. Another form in which the pure seeds are prepared is in flaked cocoa, which consists of the nibs ground up into u rather coarse uniform paste. The grinding is effected in cylinder machines, having an outer fixed casing within which a drum revolves. The nibs are fed in by a hopper on the upper part of the apparatus, and are carried round its circumference by the revolution of the drum, and delivered as a thin uniform pasty mass, the heat developed by the friction within the cylinder being sufficient to liquefy the oil, which again sets on cooling of the paste. Of late years a preparation culled extract of cocoa has como into extensive use. It is made by removing a certain proportion of the fat from the seeds, whereby the remaining substance can be ground to an impalpable powder, which yields a beverage much more palatable and agreeable to many stomachs then either entire nibs or the so-called soluble cocoas. The removal of the fat is effected Ly placing nibs, after they have been reduced by grinding to a fine yniooth paste, in bags, and subjecting them to power ful pressure in heated presses. The fat exudes slowly arid quickly solidifies, and a solid compact cake is left in the press, which only requires to be broken up and finely powdered for use. Most other preparations, whether sold as cocoa or cho colate, are mixtures of various substances with ground nibs, the object of the mixture being to mask the presence of the cocoa fat, and to render the whole readily miscible with boiling water. The ordinary distinction between thet&amp;gt;e soluble cocoas and chocolate is that the cocoa is usually sold in the form of a powder, the chocolate being made up in cakes, which require to be scraped down, boiled, and &quot; milled &quot; or frothed before being ready for drinking. la making the soluble cocoa, which is sold under such names as homoeopathic, Iceland moss, pearl cocoa, &c., the nibs aro first ground up in a heated stone mill, and, while in a soft pasty condition, thoroughly mixed with certain proportions of sugar and arrowroot, or other and inferior starches. Tho compound is afterwards ground to fine powder and sold under various names and at different prices, according to the quality of the cocoa and the nature and proportion of the ingredients which are combined with it. The finer chocolates are combinations of cocoa with sugar aloue, flavoured with some aromatic substanqg, generally vanilla; but into the composition of cheap qualities starchy substances enter, The nibs for chocolate are brought to a fine pasty state in a heated mill, and the sugar or sugar and starch with vanilla are then added and thoroughly in corporated in the mill. The paste is next passed several times between heavy horizontal rollers to produce a thoroughly homogeneous mixture. It is lastly cast into moulds while still in a thin pasty state, and after cooling it forms hard solid cakes, and is ready to wrap up for the market. Chocolates for eating are prepared with largs proportions of sugar and various flavouring substances, and the elegant preparations of these and of chocolate creams by Menier of Paris and Fry and Sons of Bristol undoubtedly form most wholesome, palatable, and nutritious confections. To the last-named firm we have to express our obligation for information courteously placed at our disposal. Preparations of cocoa are still much more largely con sumed in Spain than in any other European country. In Great Britain the consumption, [tartly stimulated by the improvements effected in its manufacture, is steadily increas ing, although as compared with the consumption of tea and