A Japanese company has begun marketing a pill that when swallowed transforms sour foods into sweet tasting comestibles for a few hours. The tablet administers a dose of miraculin, which is extracted from miracle fruit (native to West Africa). This protein tricks the brain by attaching itself to sweet receptor taste buds for a brief time before decomposing. Products with miraculin are illegal in the U.S.

Read the article.
Miracle-Fruit.net (Japanese Text)
Miraculin (Wikipedia)