The secret to coffee's success that has made it one of the world's most favorite beverages has been a mystery for a long time but thanks to a new study conducted by a team of international researchers, some of these coffee secrets are now revealed.
In the new study published in the journal Science on Sept. 5, Victor Albert, from the Department of Biological Sciences at the University at Buffalo in New York, and colleagues sequenced the genome of the Robusta coffee (Coffea canephora), which comprises 30 percent of the supply of coffee worldwide, and compared its genetic sequences with those of other plants. With the detailed genome of the coffee, some of the coffee enigmas can now be unraveled including those that involve the plant's caffeine.
Results of the analysis of the plant's genome have suggested that caffeine biosynthesis has evolved many times through distinct pathways in different plant groups as the genes in coffee that are attributed to producing caffeine are different from those that produce the compound in other caffeine producing plants such as tea and cacao.
Albert explained that coffee shared the same ancestor with chocolate and tea millions of years ago and these plants independently evolved their ability to produce caffeine after they have been separated for a very long time.
"Comparative analyses of caffeine NMTs demonstrate that these genes expanded through sequential tandem duplications independently of genes from cacao and tea, suggesting that caffeine in eudicots is of polyphyletic origin," Albert and colleagues wrote.
Although the plants have their own versions of the same caffeine genes, the researchers said that small changes have resulted in big differences in these gene's biological roles. Albert cited that while the genes responsible for caffeine production in coffee have relatives in cacao, those that are found in cacao do not actually produce caffeine but something else.
As to what gives the coffee its distinct taste and aroma, the researchers said that the genome study looked at different genes that contribute to the coffee's unique flavor.
"Our study highlighted genes that make alkaloid compounds, which are known bitter flavors," Albert said. "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."
Knowing what particular genes contribute to the taste and aroma of coffee could pave way to the production of better coffees through genetic manipulation and selective breeding.