Miracle Fruit is a plant known for its berry that, when eaten, causes sour foods such as lemons and limes subsequently consumed to taste sweet. This effect is due to miraculin.
Miracle fruit (Synsepalum dulcificum) is a type of fruit native to West Africa. Eating miracle fruit is known to alter the flavors of certain foods, for example, chewing the berries prior to eating lemon can cause the latter to taste sweet rather than sour.
Research suggests that miracle fruit's flavor-modifying effect is due to miraculin, a protein found in the berry. Miraculin appears to alter the shape of proteins on the tongue responsible for sensing sweet flavors. As a result, these proteins (known as "sweet receptors") respond to acidic or bitter foods in a way that creates a sensation of sweetness.
Although miracle fruit is often used to experiment with flavor changes, there's also widespread interest in the berry's potential health benefits. For instance, some doctors are exploring miracle fruit's ability to increase appetite in certain populations of patients (such as those undergoing chemotherapy).
Widely available in tablet form, miracle fruit is also sometimes touted as a weight loss aid. Preliminary research suggests that miracle fruit may be beneficial in the treatment of diabetes. Although miracle fruit is generally considered safe when consumed occasionally as a food, the safety of long-term use of miracle fruit supplements is unknown.