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[The following is an exact transcript of this podcast.]
If you’ve ever craved an ice-cold soda, you know that sometimes you’re just looking for something that tastes…fizzy. If that sounds odd, scientists have discovered that carbonation actually has a flavor. And that our taste buds can sense CO2.
Bubbly soft drinks tickle our tongues with their effervescence. But researchers got to wondering whether we can taste the carbonation. To find out, they studied mice whose taste cells had been turned off, one flavor at a time. So, one mouse couldn’t taste sweet things, another couldn’t taste bitter, a third couldn’t taste salt, and so on. And they found that mice lacking the cells that sense the taste sour no longer respond to CO2.
Probing further, they discovered that eliminating a single gene renders these mice blind, if you will, to the taste of carbonation. That gene encodes an enzyme that breaks down CO2—and water…don’t forget the water—into bicarbonate and protons. And it’s the protons—which are essentially acid—that the sour-sensitive cells seem to sense. The work appears in the journal Science.
The scientists speculate that our CO2 sensor evolved to help us avoid food that’s spoiled. Yet we still like some of our drinks to include the delightfully acidic tingle of a touch of CO2.
—Karen Hopkin
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12 Comments
Add CommentThat's an awfully cruel thing to do to an animal, all so someone can show that people are able to taste carbonation. Hell, I could have told them that.
Reply | Report Abuse | Link to thisCan one taste carbonation? Hello - has anyone ever tasted sparkling water?
Reply | Report Abuse | Link to thisI have always suspected that humans can detect light and sound too, but I've never seen a study proving it. Makes you wonder...
Reply | Report Abuse | Link to thisI don't really see the cruelty that Dolmance mentioned, unless the mice were physically harmed. Maybe the mice will never be able to enjoy a cheeseburger as much as the other mice, but I doubt it bothers them. As for the relevance of the study, I imagine they were trying to determine if the sensation of carbonation was merely tactile or if there was a taste component. I had actually assumed it was flavorless.
Reply | Report Abuse | Link to thisOops, the last word of my statement was "flavorless," I meant "tasteless."
Reply | Report Abuse | Link to thisThen you wouldn't mind going through the procedure yourself?
Reply | Report Abuse | Link to thisCome on.
It's genetic engineering, it's not like they physically remove their taste buds. There is nothing cruel about it.
Reply | Report Abuse | Link to thisWhat the podcast doesn't mention, and that I heard elsewhere, is that the experiment was about how we detect it - whether by feeling the bubbles on the tongue as previously suspected, or by detecting the CO2 itself. There was another experiment in which people drank soda in a pressure chamber so that it did not bubble. They still tasted the carbonation.
Reply | Report Abuse | Link to thisDuh. Sour is the taste of acids. Carbonated water is acidic. These are facts I've known since I was in high school. These facts have been known well over a century.
Reply | Report Abuse | Link to thisThey probably got a big government grant to study this "issue". Next on the agenda: does water feel different than air?
Reply | Report Abuse | Link to thisThese mice were born for no other reason. Come on now.
Reply | Report Abuse | Link to thisYou could have just asked me. Carbonated beverages taste terrible to me and hurt my mouth and throat. (Feels like swallowing a mouth full of needles.) The released gas does taste acidic. Maybe the bubbles irritate the mice too?
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