WASHINGTON - Scientists have devised a small, cheap, lab-on-a-chip sensor that quickly and accurately identifies sweetness.

It can accurately identify the full sweep of natural and artificial sweet substances, including 14 common sweeteners, using easy-to-read colour markers.

“We take things that smell or taste and convert their chemical properties into a visual image,” said study leader Kenneth Suslick, University of Illinois at Urbana-Champaign (UI-UC).

This sensory “sweet-tooth” shows special promise as a simple quality control test that food processors can use to ensure that soda pop, beer, and other beverages taste great with a consistent, predictable flavour.

The new sensor, about the size of a business card, can also identify sweeteners used in solid foods such as cakes, cookies and chewing gum.

Suslick’s team has spent a decade developing “colorimetric sensor arrays” that may fit the bill. The “lab-on-a-chip” consists of a tough, glass-like container with 16 to 36 tiny printed dye spots, each the diametre of a pencil lead.

To the scientists’ delight, the sensor identified 14 different natural and artificial sweeteners, including sucrose (table sugar), xylitol (used in sugarless chewing gum), sorbitol, aspartame, and saccharin with 100 percent accuracy in 80 different trials, said an UI-UC release.

Researchers have tried for years to develop “electronic tongues” or “electronic noses” that rival or even surpass the sensitivity of the human tongue and nose.

But these devices can generally have difficulty distinguishing one chemical flavour from another, particularly in a complex mixture. Those drawbacks limited their practical applications.

Their study was presented at the American Chemical Society’s 238th National Meeting in Washington D.C.