Washington, Aug 18 - 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.