The Miracle Fruit plant (Synsepalum dulcificum)
produces berries that, when eaten, cause bitter and sour foods (such as lemons and limes) consumed later to taste sweet. The berry, also known as Miracle
Berry, Magic Berry, Miraculous Berry or Flavour Berry.
The berry contains an active glycoprotein molecule, with some trailing carbohydrate chains, called miraculin.When the fleshy part of the fruit is eaten, this molecule binds to the tongue's taste buds, causing bitter and 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". This effect lasts between thirty minutes and two hours.