There are three undesirable components in pineapple that may cause trouble:
Glycosides, which are organic compounds, can be somewhat irritating to human skin and oral mucous membranes. This is why eating raw, unprocessed pineapple can cause an itchy mouth, but it does not pose a direct health hazard.
Serotonin, a nitrogen-containing organic compound, has a potent effect of constricting blood vessels and raising blood pressure. Each 100 grams of pineapple juice contains 2.5 mg to 3.5 mg. The direct reaction to consuming too much is a headache.
Bromelain, a proteolytic enzyme. When extracted, it has a strong effect of breaking down fibrin and blood clots, making it useful in medicine.
The small amount of bromelain in pineapple is broken down and destroyed by gastric juice once it reaches the stomach. However, a small number of people are allergic to this enzyme. Symptoms such as abdominal pain, nausea, vomiting, urticaria (commonly known as hives), headache, and dizziness may appear 15 to 60 minutes after consumption. In severe cases, difficulty breathing and shock can occur. This is what is meant by pineapple allergy.
Prevention methods:
After peeling and coring the pineapple, cut it into slices or pieces and blanch it in boiling water before eating. Bromelain begins to denature and lose its function at 45-50°C, and over 90% of it is destroyed at 100°C; glycosides are also simultaneously destroyed and removed; and serotonin dissolves in water. The flavor is also improved after boiling.
If you wish to maintain the fresh taste of the pineapple, you can soak the sliced or cubed pineapple in salt water (about the same salinity as used for cooking) for about 30 minutes, then rinse it with cool water to remove the salty taste. This method can also achieve a desensitizing effect.