Species
Among more than a dozen known species of the genus coffea, only two have economic significance, for its extensive cultivation. They are the Coffea arabica, commonly known as arabica, and Coffea canéphora, known as robusta. There is a third species, Coffea libérica, known as coffee Liberia, whose cultivation is marginal compared to the previous two.
The cultivation of Arabica is more widespread than the robust, representing about two thirds of world production.
The grains of the two most common species, arabica and robusta, are similar to the naked eye when they have been roasted, but in reality, there are many differences between the two species.
The arabica, genetically, it has 44 chromosomes against 22 of the sturdy. The color of the leaves and fruits of the two species are different, and plant height.
The arabica reached, when it grows freely, from 6 to 8 metres, while the robusta tends to be higher, from 8 to 10 meters. The plant is robust tougher, as its name implies, to attacks by parasites, disease and heat. The arabica is particularly susceptible to a disease called rust (Hemileia vastatrix), especially when planted in areas at low altitude. This is one of the reasons for locating plantations arabica usually at an altitude of 900 to 2,000 meters.
But the big difference between the two species is in the green beans. The grain of arabica is more elongated and flattened, its green color is more intense, and sometimes shows blue hues. It has, moreover, a central winding path. The grain of robust, in contrast, is more convex and domed, with a central groove straight, and their color is pale green with brown or grey shades.
From a chemical point of view, the wheat from the arabica contains from 1.1 to 1.7% of caffeine, while the robust contains from 2 to 4.5%. Acids chilorgénicos (substances that can cause gastric disorders consumers) are in higher amounts in the grain from the robust than that of arabica. And the flavor in the cup in the two species is not like that of the arabica is more sweet and aromatic and noticeably less bitter and astringent that experimented with the robust. The drink is obtained from robust stronger and more bitter.
There are other differences between the two species that most often interested specialists. However, we will note a few:
A.La plant is more robust than the arabica branched.
B.El number of clusters per axilla is higher in the kind of robust than that of arabica, and the flowers are larger.
C.La arabica is autógama, ie flowers autopolinizan, while that of robusta requires a work of pollination.
Coffee arabica from the species is considered much higher than that obtained by robust.