This one is for all the foodies out there:

Miracle fruit secret revealed

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Researchers and foodies alike have long known the effects of the miracle fruit (a.k.a. Richadella dulcifica). At flavor-tripping parties, guests will pop a berry then chew, chew and chew some more, letting the masticated fruit linger on the tongue. Then the sampling begins: Guinness tastes like a chocolate shake, Tabasco loses its sting and pickles their mouth-pinching tang. Lemons and limes gush with sweetness.

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.

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