The most famous coffee bean is the Coffea seed, evergreen shrub belonging to the botanical family of the Rubiaceae.
There are more than 80 kinds of Coffea, but only two are used commercially extracting their seeds, which, once roasted and ground, give origin to coffee: Coffea arabica and Coffea canephora, better known as Arabica and Robusta. Arabica has been the first used Coffea, and different species of it are cultivated, featuring low caffeine content, but rich in aroma and with a pleasant acid level. Coffea Robusta has a higher resistance to parasites and weather conditions, such as higher temperatures and abundant rainfalls.

The coffee obtained from its round and yellow (or yellow-brown) beans is more full-bodied and stronger, with a higher caffeine content. Although the World Health Organization describes it as “nun nutritive dietary component”, in other words a non-food, it is unlikely to find another beverage that is as rich in active and inactive ingredients as coffee. In fact, about 900 substances have been identified in coffee, among which minerals (potassium, calcium, magnesium, phosphates and sulphates). However, the most important substance as for concentration and features is caffeine.