cacao (kəkä´ō, –kā´–), tropical tree (Theobroma cacao) of the family Sterculiaceae (sterculia family), native to South America, where it was first domesticated and was highly prized by the Aztecs. It has been extensively cultivated in the Old World since the Spanish conquest. The fruit is a pod containing a sweetish pulp in which are embedded rows of seeds, the cocoa "beans" of commerce. To obtain cocoa, the harvested pods are fermented by naturally occurring bacteria and yeasts to eliminate their bitter, astringent quality. The seeds are then cured and roasted. The clean kernels, called cocoa nibs, are manufactured into various products. Their large percentage of fat, removed by pressure, is the so-called cocoa butter used in fine soaps and cosmetics and in medicine for emollients and suppositories; the residue is ground to a powder (cocoa) and used for beverages and flavoring. Chocolate is a product in which the cocoa butter has been retained. Cacao products have a high food value because of the large proportion of fat, carbohydrates, and protein. Cacao is classified in the division Magnoliophyta, class Magnoliopsida, order Malvales, family Sterculiaceae.