Tongue numbness after eating pineapple is because pineapple contains pineapple enzyme, which breaks down proteins and causes tongue numbness after eating. Therefore, it is recommended to soak the pineapple in salt water or heat it at high temperature before consumption. 1. Soak in salt water: Soak the pineapple in lightly salted water for about 30 minutes before eating it, which can make the protease in pineapple inactive and reduce the acid content. 2. High-temperature heating: Boil the pineapple in water or microwave it for 3 minutes to destroy the irritants in the pineapple and prevent tongue numbness after eating it. If tongue numbness occurs after eating untreated pineapple, you can rinse your mouth well with hot water or light salt water, which can neutralize the symptoms of tongue soreness and relieve the symptoms.