Cocoa And Chocolate
The Tree, The Bean The Beverage

HARVESTING AND PREPARATION FOR MARKET 61 diminish in quantity and change from snow-white to dirty brown. A planter judges entirely from such external signs when the cacao is sufficiently fermented, although the extraordinary changes which occur in the bean itself are of greater importance to the cocoa manufacturer. Changes Due to Fermentation Inside the Bean. The actions which. take place in the fruity pulp are similar to those which occur generally in fruit juices or liquids containing fermentable sugars, but the reactions in the interior of the bean are more rare and peculiar. The acidulous liquid penetrates and permeates the bean changing the violet of the Forastero beans to a red, and spreading the colour more or less evenly throughout the bean. Other and more subtle effects are produced. Of these, only the most important one has received much consideration ; this is a change of colour due to the development of a brown substance in the bean. Whilst this phenomenon is not so well known as that due to yeast fermentation, it is not difficult to cite familiar examples. Everyone has observed the browning of apples and pears when they are bruised or cut and left exposed to the air. Many will have noted the same colour change in peaches, grapes, acorns, horse-chest-nuts and broad-beans. Those who know the tropics will have noted the development of a brown colour in kola nuts and in tea and tobacco leaves. The change in colour in cacao beans, as probably in all the cases cited above, is due to the action of the oxygen of the air on a particular constituent which resembles a tannin. The oxidation of the tannin to a brown substance is rendered possible by the presence in the bean of minute quantities of an oxidase, which is a substance of unknown Constitution and composition formed in living matter and capable of starting oxidation. The