text: Do Pineapples Have Poison? - lumparland.com
  Why does pineapple hurt tongue?
  Though fruits and vegetables can be very healthy for you some can actually cause or worsen canker sores. Acidic fruits such as oranges, lemons, pineapples and grapefruits can cause stress on the tissue in the mouth. People with mouth sensitivities can also be prone to reactions with certain foods.