Miracle Fruit Secret Revealed

You may remember “miracle fruit” from such posts as “Food Dude Hosts Wild Miracle Fruit Party!” For those who are unfamiliar with Synsepalum dulcificum, here is a quote from the New York Times –

…Mr. Aliquo greeted new arrivals and took their $15 entrance fees. In return, he handed each one a single berry from his jacket pocket. “You pop it in your mouth and scrape the pulp off the seed, swirl it around and hold it in your mouth for about a minute,” he said. “Then you’re ready to go.” He ushered his guests to a table piled with citrus wedges, cheeses, Brussels sprouts, mustard, vinegars, pickles, dark beers, strawberries and cheap tequila, which Mr. Aliquo promised would now taste like top-shelf Patrón.The miracle fruit, Synsepalum dulcificum, is native to West Africa and has been known to Westerners since the 18th century. The cause of the reaction is a protein called miraculin, which binds with the taste buds and acts as a sweetness inducer when it comes in contact with acids…

An interesting piece of the miracle fruit puzzle was that researchers weren’t exactly sure how the fruit can change our perception of flavor. This week an article in Science News sheds light on the subject (membership required).

Scientists have finally explained how a little red berry makes just about anything, from the sourest lemon to the bitterest beer, taste as sweet as honey. A protein found in the fruit tickles the tongue’s sweet-sensing machinery, its effects intensifying in the presence of acidic flavors like citrus and carbonated drinks.

…While the active ingredient in miracle fruit — miraculin — has been known for decades, it hasn’t been clear exactly how the protein confers its sweetness. Now scientists in Japan and France report that miraculin’s interaction with the tongue’s sweet sensors depends on the acidity of the local environment. At a pH of 4.8 (water is neutral with a pH close to 7), the sweet-tasting cells respond twice as vigorously to miraculin than they do at a less acidic pH of 5.7. At closer-to-neutral pH levels of 6.7 and higher, the protein seems to slightly shift shape, blocking the sweet sensors but not activating them. This explains why under certain conditions sweet foods may taste less flavorful after eating the berry, researchers led by Keiko Abe of the University of Tokyo report online September 26 in the Proceedings of the National Academy of Sciences.

It is an interesting article and will give you plenty of fodder to impress your friends at your next dissertation.