Chilled Out

Andy Coghlan / New Scientist 12dec01

GET ready to chill out with the world's coolest drinks. The secret? A natural food additive with 35 times the cooling power of menthol--but no minty flavour whatsoever.

It could bring a supercool fresh tang to a wide range of products, including beer, bottled water, citrus drinks, chocolate and confectionery, says Thomas Hofmann, whose team at the German Research Centre for Food Chemistry in Garching, Munich, discovered the new substance. And because it "cools" skin 250 times as intensely as mint, they say it could add fresh zest to cosmetics such as anti-perspirants.

The effects of the new substance last for half an hour, twice as long as menthol, the extract that gives peppermint and spearmint their icy zing. "We've found the world's most powerful natural cooling agent without a mint odour," says Hofmann.

"It's a fascinating discovery," agrees Andy Taylor, a flavour technologist at the University of Nottingham. "I don't think anyone has ever found a cooling agent without menthol flavour," he says.

Hofmann's team isolated the substance from roasted dark malt, a key ingredient for brewing beers and whiskies. It belongs to a family of chemicals called cyclic alpha-keto enamines. When a panel of tasters sampled the substance, they found it cooled as well as menthol even when concentrations were 35 times lower. It also cooled skin as effectively at concentrations 250 times lower.

Hofmann says that like menthol, the substance "cools" by its effect on nerve endings. "There's no evaporation, and no temperature change," he says. So cooling is a slight misnomer. Nevertheless, Taylor says that like menthol, the substance activates so-called "trigeminal" receptors found throughout the mouth, cheeks and throat. They seem to register spice-based "temperature"--anything from the hotness of curry to the coolness of menthol, he says.

Hofmann says it won't replace menthol in products such as mints, chewing gums, toothpastes and mouthwashes. But because it has no taste, you can give a fresh zing to a massive range of things without altering the flavour.

And since we've been consuming the substances for centuries in beer and whisky, it is unlikely to be harmful, he says. The first "supercooled" products could be on the market within two years, says Hofmann.

Graham Young, president of the British Society of Flavourists, says there are already some artificial cooling agents, but this is the first natural one apart from menthol. "It could be useful from a marketing point of view," he says.