The team, from CIRAD in France and Brazil's Agricultural Institute of Paraná, says it has pin-pointed the genes responsible for sucrose accumulation in coffee beans.
Sucrose is thought to play a vital role in the taste of coffee by releasing flavour and aroma during roasting.
The discovery, which is the result of five years' research, may pave the way for higher quality coffee, potentially widening the added value sector of the coffee market and so improving earnings in the supply chain.
One enzyme, sucrose synthetase, is responsible for sucrose accumulation in arabica coffee beans, the team found. The enzyme exists in the form of two different proteins and is coded within two different genes.
Further testing found that the first gene controlled sucralose accumulation in coffee beans during ripening and picking, while the second was involved in sucrose breakdown during the roasting process.
"This is a new step along the way to producing exceptional coffees," the team said. The aim now is to identify ways of improving sucrose content in beans and managing its production so as to guarantee end product quality.
Higher quality coffee may open up new added value opportunities for both growers and coffee firms, something many in the industry believe will be crucial in raising earnings further down the supply chain.
Coffee prices crashed a few years ago, leaving producers with little income. The last year has seen a resurgence, together with a growing trend for fair trade, but most farmers are still being paid less for their beans than they were 20 years ago, according to International Coffee Organisation figures.