There are three kinds of bad ingredients in pineapple: malnutrition-irritating to human skin and oral mucosa, which will cause itching; Serotonin, which strongly constricts blood vessels and raises blood pressure, can cause headaches; There is also bromelain, although it will be destroyed by gastric acid decomposition, but there are still a few people who will have abdominal pain, nausea, vomiting, rash, headache, dizziness and other symptoms about 15-60 minutes after eating. If you want to keep the fresh taste of pineapple, you can soak it in salt water (generally the salinity of cooking) for 30 minutes, and then soak it in cold boiled water to remove the salty taste, so as to achieve desensitization, and then eat it.