Coffee could hold the secret to keeping bad breath at bay.

The beans contain compounds that prevent bacteria releasing the gases behind halitosis, research shows.

Pinpointing the key chemicals could lead to coffee ‘mints’ or pastilles that stop bad breath at the source.

Professor Mel Rosenberg, who has spent two decades studying the diagnosis and treatment of halitosis, actually set out to investigate why coffee causes bad breath.

But his work at Israel’s Tel Aviv University showed that while it may cause problems in our mouths, it has quite the opposite effect in the test tube.

Adding black coffee to ‘soups’ of bacteria-filled saliva blocked the release of gases that cause breath to smell. In some cases, the amount of gas was cut by up to 90 per cent.

The researcher said: ’ We expected that coffee would cause bad breath but there is something inside this magic brew that has the opposite effect.’

The professor, a microbiologist and inventor of the Dentyl range of mouthwash, now hopes to isolate the bug-busting chemical.

He still believes coffee has a negative effect on breath which could be caused by milk fermenting in the mouth or drying it out.

By Fiona Macrae
dailymail.co.uk