Caffeine-free coffee tree is discovered

A naturally caffeine-free coffee plant has been found growing wild in Ethiopia, heralding the prospect of a cup of freshly-ground arabica that will not keep you awake.

A naturally caffeine-free coffee plant has been found growing wild in Ethiopia, heralding the prospect of a cup of freshly-ground arabica that will not keep you awake.

Scientists in Brazil have discovered three arabica coffee plants that do not produce caffeine in their leaves or beans among a batch of 6,000 wild specimens originally collected in the late 1980s.

The scientists believe the wild plants could be cultivated to produce their own caffeine-free beans, or could be cross-bred with other varieties of arabica coffee to introduce the natural caffeine-free trait into commercial crops.

About 10 per cent of the coffee consumed in the world is processed to remove caffeine, a natural chemical linked with heart palpitations, raised blood pressure, anxiety, tremors, gastrointestinal upsets and insomnia. But the decaffeination process also removes organic compounds that can affect coffee's taste and aroma.

The wild plants that lack caffeine were found by a team led by Paulo Mazzafera, professor of plant physiology in Brazil, whose study is published in the journal Nature. "We have discovered a naturally decaffeinated Coffea arabica plant from Ethiopia, a species normally recognised for the high quality of its beans," he said.

It is not known why coffee plants normally produce caffeine, which is also produced in the leaves of unrelated plant species such as tea and cocoa.

"We can find it in more than 60 species of plants in nature. We don't know why it's there, it does not seem to be a simple waste product of plant metabolism, nor does it protect against insect pests," Professor Massafera said.

The three decaffeinated coffee plants do not look any different from other arabica plants but chemical analysis reveals that the wild plants have a caffeine content of 0.06 per cent, which compares with a content of about 2 per cent in roasted coffee beans of ordinary plants and 0.03 per cent in processed decaffeinated coffee.

It is possible that the wild caffeine-free plants carry a genetic mutation that interferes with a natural enzyme called caffeine synthase, which is involved in producing caffeine.

British and Japanese scientists have been working on ways of ridding caffeine by genetically altering such genes but in the current anti-GM climate it was unlikely that consumers will accept such a product, Professor Massafera said.

"This wild plant produces a naturally decaffeinated coffee bean. It's a product for those who don't like GM organisms and who like the taste of non-decaffeinated coffee," he said.

The Brazilian team hopes to begin a cross-breeding programme between the wild arabica plant and local commercial varieties to produce a hybrid which gives a good crop of decaffeinated beans.