http://en.wikipedia.org/wiki/Miracle_fruit
http://www.nytimes.com/2008/05/28/dining/2...ruit&st=cse
QUOTE
Tokyo dieters with a sweet tooth can enjoy cakes and fruit ices with minimal sugar and no artificial sweeteners at a new cafe that opened last week. The desserts are unpalatably sour in taste, but customers are instructed to chew on an African berry, called “miracle fruit,” which contains a protein that causes the taste buds to temporarily sense sour as sweet.
QUOTE
The berry contains an active glycoprotein molecule, with some trailing carbohydrate chains, called miraculin.[5][6] When the fleshy part of the fruit is eaten, this molecule binds to the tongue's taste buds, causing sour foods to taste sweet. While the exact cause for this change is unknown, one hypothesis is that the effect may be caused if miraculin works by distorting the shape of sweetness receptors "so that they become responsive to acids, instead of sugar and other sweet things".[3] This effect lasts between thirty minutes and two hours.






















