Bitter blockers: Making life taste sweeter

Scientists have found a way to switch off the bitter after-taste associated with artificial sweetners...

Substances like saccharin are popular alternatives to sugar because, despite tasting extremely sweet, they contain very few calories. But they also, unfortunately, trigger the tongues' "bitter buds", producing an unpleasant after-taste that can put off some consumers.

Now, scientists from the US and Europe have found a way to block the effect. Writing in Current Biology, Jay Slack, a researcher at Givaudan Flavours Corporation in Cincinnati, explains how he and his colleagues have identified the chemical GIV3727 (or, to give it its proper name, 4-(2,2,3-trimethylcyclopentyl)butanoic acid) that blocks the tongue's bitter receptors, negating the after-taste effect.

The team made the discovery by adding the genes encoding the tongue bitter receptors to cultured cells, effectively giving them a sense of taste.

By incubating the cells in a solution of artificial sweetener but then also introducing potential "bitter blocker" molecules and watching the chemical response of the cells, the team were able to whittle down nearly 18,000 chemical candidates to 139 promising compounds. Of these, GIV3727 showed the potency.

Subsequent tests on human volunteers confirmed that the agent could mask the bitter aftertones associated with sweeteners. The team suggest that, apart from making sweeteners taste more pleasant, the agent could be used to make certain medicines more palatable, or even introduce entirely new flavour sensations when combined with certain foods...