In research published online in the Proceedings of the National Academy of Sciences and led by the University of Tokyo’s Keiko Abe, it was explained how the fruit miraculin can add a sweet taste to a variety of food products. It was discovered a protein found in the fruit sets off the tongue’s sweet-sensing abilities, with its effects intensifying in the presence of acidic flavors.
The research found interaction with the tongue’s sweet sensors depends on the acidity of the local environment. At a pH of 4.8, the sweet-tasting cells respond twice as much to miraculin than they do at a less acidic pH of 5.7. At pH levels of 6.7 and higher, the protein seems to shift, blocking the sweet sensors but not activating them. This explains why under certain conditions sweet foods may taste less flavorful after eating miraculin.
However, while miraculin does increase sweetness, the protein's use has not been approved by the U.S. Food and Drug Administration. Also, because it is a protein, it would likely fall apart if heated, making it unlikely to be useful in applications such as baked goods.