Gastronomists revel in its pungent taste while most people are repelled by its odour, but no one perhaps can remain indifferent to garlic. Besides indulging the taste buds, the white cloves have been recommended as a cure for various ailments from common cold to cancer. A flavouring agent known for thousands of years, garlic's pungency has intrigued cooks and scientists alike. Now, a team of academic and industrial researchers from the Scripps Research Institute (SRI), the Genomics Institute of the Novartis Research Foundation, both in the US, and the Korea University College of Medicine has found what makes garlic acrid (Current Biology, May 24, Vol 15, No 10).

They found raw garlic is full of sulphurous compounds, including a chemical called alliin, which is responsible for its peculiar taste. Alliin is concentrated within the body of the garlic, making up about 0.25 per cent of the mass of any given clove. The chemical acts on specialised neurons (nerve cells) embedded in the skin, including the mouth and tongue, that the human body uses to detect temperature and pain, producing the "kick'.

Led by Ardem Patapoutian and Lindsey Macpherson, both from SRI, the team of scientists is now showing that the chemical difference between raw and cooked garlic is the loss of allicin which can account for the change in pungency.