Yummy? Thank the bacteria in your mouth

Find the taste really yummy? Thank the bacteria in your mouth that imparts those delicious and distinctive flavours.

Christian Starkenmann and colleagues who conducted research into taste pointed out that some fruits and vegetables release characteristic odours only after being swallowed.

Scientists performed sensory tests on 30 trained panelists to evaluate the odour intensity of volatile compounds - known as thiols - that are released from odourless sulphur compounds found naturally in grapes, onions, and bell peppers.

It took participants 20 to 30 seconds to perceive the aroma of the thiols - and this perception persisted for three minutes, according to a release of the American Chemical Society (ACS).

The researchers also determined that the odourless compounds are transformed into the thiols by anaerobic bacteria residing in the mouth - causing the characteristic 'retroaromatic' effect.

"The mouth acts as a reactor, adding another dimension to odour perceptions," they explained. However, the authors conclude, it is saliva's ability to trap these free thiols that helps modulate the long-lasting flavours.

The study will appear in Wednesday's edition of the ACS bi-weekly Journal of Agricultural and Food Chemistry.

Last updated on Nov 11^th, 2008 at 16:32 pm IST--IANS