The pineapple contains alkaloids called bromelain, an enzyme of proteolysis that occurs in the biochemical reaction of hydrolysis of muscle tissue, which can dissolve the fibrin in muscle tissue, and the tongue is stimulated with a tingling sensation, so before eating the pineapple is generally soaked in light salt water for more than 30 minutes to minimize the concentration of bromelain and minimize the stimulation of the muscle. The tingling sensation is also not sensitive. What if I eat a pineapple that has not been treated with light brine and my tongue hurts? To gargle with light salt water, gargle several times to dilute the pineapple prion enzyme, the effect of dissolving muscle tissue will gradually disappear, so the stinging sensation will gradually be relieved.