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Archive for Thursday, August 31, 2000

Researchers engineer decaf plants

August 31, 2000

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A new way to keep the caffeine out of coffee and tea, without having to take it out, could soon be developed through genetic engineering, scientists announced Wednesday.

Based on recent experiments in the plants that grow coffee beans and tea leaves, researchers in Japan and Scotland think they can block the chemical pathway in which caffeine is made. The result would be beverages with all the flavors and aromas of the good stuff, minus the kick from caffeine.

"We have cloned the gene encoding caffeine synthase," an enzyme, "from young leaves of tea, opening up the possibility of creating tea and coffee plants that are naturally deficient in caffeine," the researchers said.

The researchers -- Misako Kato and Hiroshi Ashihara at Ochanomizu University, Kouichi Mizuno and Tatsuhito Fujimara at Tsukuba University in Japan, and Alan Crozier, at the University of Glasgow in Scotland -- report their results in today's issue of Nature.

The gene they've isolated makes an enzyme that coffee and tea plants need to finish the last two steps in caffeine production. By removing the gene or shutting down its activity, the complete caffeine molecules would never get made by the plants.

Caffeine, a stimulating chemical, is a natural part of coffee beans and tea leaves, and is often added artificially to some beverages to give them more jolt. But there has been long and continuing debate about the long-term health effects of caffeine consumption.

At present, coffee and tea are decaffeinated in the "super-critical fluid extraction" process, using carbon dioxide. A less-favored way to get the caffeine out is to use extraction solvents, which can leave potentially toxic residues. Both methods add expense and complications to the production process.

According to the researchers, the demand for decaffeinated beverages has been increasing because of concerns about such caffeine-induced symptoms as palpitations, gastric disturbances, anxiety, tremor, increased blood pressure and -- most prominently -- insomnia.

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