Miraculin

Miraculin is a taste-modifying glycoprotein derived from the fruit of Synsepalum dulcificum, commonly called miracle fruit, a berry native to West Africa first documented by the explorer Chevalier des Marchais during an eighteenth century expedition. The protein is not itself sweet; instead, when it contacts the taste buds it binds to sweetness receptors so that sour foods such as citrus taste sweet, an effect that persists for one to two hours after consumption.