1. Introduction
Whilst arabica coffee (C. arabica) is the most highly commercialized variety in the world, robusta coffee (C. canephora) has been responsible for 25% of the exportable coffee on the world market in the last 10 years (Delaporte, 1991, Hesse, 1990 and Toledo and Barbosa, 1998). Currently it is mainly cultivated in Indonesia, Brazil, Vietnam, The Ivory Coast and Uganda. The predominance of arabica coffee over robusta coffee is due essentially to consumer preference for the aroma and flavour of the former, commonly described as rich, that of robusta coffee frequently being described