Cacao
As currency, beverage, and divine plant, cacao (Theobroma cacao, family Sterculiaceae) has played an important role in ancient Central American cultures. To the Mayans, the plant was a gift from their gods—implied in the name Theobroma, Latin for "food of the gods." The dried seeds were important in Aztec society as a unit of currency (used in the Yucatan Peninsula until the 1850s), and as part of a drink reserved for the nobility. Today, cacao is probably best known for the sweet, rich food produced from the seeds called chocolate.
Cacao is typically a small-to medium-sized deciduous tree of the New World tropical forests. The small, cream-colored flowers are produced directly from the woody trunks and branches of the tree, not in the leaf axils, where most other flowering plants produce flowers. Following pollination, pods are produced, ranging in color from green through yellow to red-brown. Each pod contains between twenty and sixty seeds that are surrounded by a thick, whitish pulp. Seed dispersal in the wild is usually by monkeys.
Although presently distributed throughout Central America due to migration and dispersal by the Mayans, cacao is thought to have its origin in the eastern Andes. Cultivation has led to the production of two
forms of cacao: Criollo, from Central America, and Forastero, from South America. Trinitario is a form produced by breeding criollo and forastero types. At the turn of the twenty-first century, cacao is grown commercially in parts of West Africa, Malaysia, Brazil, Central America, and parts of Mexico.
Processing Cacao
The process of producing chocolate from cacao seeds is complex. Following harvesting, ripe pods are opened, the seeds removed, and the pulp scraped away from the seeds. At this point, the light-brown seeds have no discernible chocolate taste. Piles of cleaned seeds are allowed to ferment for up to one week, during which time the chocolate flavor begins to develop as polyphenols start to break down. During the fermentation process, the embryos of the seeds are killed and any remaining pulp is broken down. The color of the seeds also changes to purple. Following fermentation, the seeds are dried, sorted, and shipped to processing factories.
At the processing factory, roasting the seeds removes any remaining water and acids and allows the chocolate flavor to develop. Roasting is done at 121°C for seeds used to produce chocolate, higher for cocoa powder. The roasted seeds are then cracked and the seed coats removed, leaving the cotyledons (known as chocolate nibs), which are then ground using rollers.
During the grinding process, sufficient heat is generated to melt fats in the chocolate nibs, producing a fine paste called chocolate liquor. Baking chocolate is molded, set chocolate liquor. Subjecting the nibs to high pressure prior to grinding removes up to 30 percent of the fats and yields a dry cocoa powder. The fats are called cocoa butter, and they may be used later in the production procedure. Most chocolate is treated with alkalis to neutralize organic acids that are still present in the chocolate. This process, called dutching, produces a mild, dark chocolate.
Milk chocolate is produced by adding condensed milk to chocolate liquor. Stirring the chocolate results in very finely ground cacao particles, which yields a very smooth chocolate. Finally, the addition of extra cocoa butter produces some of the smoothest and creamiest of chocolates.
Chocolate acts as a mild stimulant due to the presence of the alkaloids theobromine, caffeine, and theophylline. The caffeine can be extracted from the discarded seed coats and used in drinks and medicines; extracted theo-bromine can also be chemically converted into caffeine.
