Why pineapple burns the tongue: the science behind the sting

Pineapple, a tropical fruit valued for its sweet flavor and rich nutritional profile, contains high levels of vitamin C along with essential minerals such as manganese and potassium, according to scientific assessments. The tingling or mild burning sensation the fruit can leave in the mouth is caused primarily by bromelain, an enzyme that breaks down proteins. When fresh pineapple is chewed, the enzyme comes into contact with the protective proteins on the mucous membrane and the surface of the tongue, producing a brief tingling feeling at the microscopic level. The effect is temporary, as oral tissues regenerate quickly and no lasting damage occurs. The intensity of the sensation can vary from one piece of fruit to another and from person to person, depending on the concentration of the enzyme. Once the bromelain reaches the stomach, strong acids neutralize it, limiting its activity to the surface of the mouth and giving pineapple its characteristic sensory feel.