The secrets of coffee unlocked

Scientists have unlocked the genome, or the gene material that makes coffee what it is.

After water, coffee is the second most consumed beverage and the second most traded commodity after petroleum. One of three of the 2.25 billion cups of coffee consumed worldwide each day comes from Robusta (Coffea canephora); almost all the rest comes from its relative, the Arabica. That makes coffee one of the world's most important crops, cultivated in more than 11 million hectares in 70 countries and exported by 60 nations.

Coffee is highly valuable because of its flavor, aroma and caffeine, the stimulant that it produces. 

“We generated a high-quality draft genome of the species Coffea canephora,” said lead author France Denoeud of the Commissariat à l’Energie Atomique, Genoscope, Institut de Génomique and the Université d’Evry in France.

The study found that coffee chromosomal regions show unique one-to-one correspondences with grapevine chromosomes and a one-to-three correspondence with the tomato genome.

Caffeine is synthesized in both coffee leaves, where it has insecticidal properties, and in the fruits and seeds, where it inhibits seed germination of competing species. 

Linoleic acid is the major polyunsaturated fatty acid in the coffee bean where it contributes to aroma composition and flavor which lingers after roasting. 

According to the Editor's Summary, scientists have seen similar but independent expansions in distantly related species of tea and cacao, suggesting that caffeine might have played an adaptive role in coffee evolution.

The study—“The coffee genome provides insight into the convergent evolution of caffeine biosynthesis”—is published online in the September issue of the Journal Science.

Studying the genes behind coffee's flavors and aromas may enable scientists—through selective breeding or genetic engineering—to breed coffee with enhanced characteristics, according to smithsonia.com.

“Our study highlighted genes that make alkaloid compounds, which are known bitter flavors,” it quotes the study's co-author, Victor Albert, a plant evolutionary biologist at the University of Buffalo. “We found another group of enriched enzymes that make flavonoid compounds, which are another taste element. We also highlighted the genes involved in fatty acid pathways, so we've identified many different genetic aspects of aroma and flavor.”

“There's a big research area in designer enzyme chemistry, where people modify enzyme groups in small ways for them to take on completely new functions,” Albert says. “That kind of designer chemistry was accomplished accidentally by caffeine-producing plants in nature.” 

The Department of Agriculture’s Bureau of Agricultural Statistics puts local coffee production at 96,433 metric tons. The Philippines lies in a narrow area in the world called the coffee belt, making it one of the few countries that can grow four varieties of coffee: Arabica, Excelsa, Liberica and Robusta. (SciencePhilippines)