How does pineapple react with water? After having bought my first pineapple, I had been instructed to be careful about washing my hands if I ever got pineapple on it (after slicing it open). Furthermore, I was told that I shouldn't wash the pineapple fruit with any water, but that I could only do it after cooking the water first. Both of these were explained as their being a sort of reaction that the pineapple has on contact with water. Reminds me of those chemical reactions with sodium and water.

The problem is, I couldn't get a satisfactory explanation of what the reaction was. The reasoning behind the reaction was not given, and when I asked what the reaction caused, the only explanation I received was "it is like that funny taste you sometimes get in your mouth when eating pineapple". I should note that I've never had a funny taste in my mouth when eating pineapple, so this explanation wasn't helpful.

What is the reaction that pineapple has when it comes into contact with water? Does it have dangerous effects, or is it mostly just affect the flavor of the fruit?
I have never heard the water-pineapple thing. It may be a confused result of the fact that fresh pineapple cannot be put in a gelatin because there is an enzyme in pineapple (and papaya) that breaks down the structure of the gelatin and it will never set. Canned pineapple is fine to put in gelatins though, the canning process breaks down the enzyme. I have definitely gotten water on pineapple (in fruit salads from other fruits) though, and I didn't explode... It might also just be that pineapple doesn't need or benefit from washing and it turned into 'NEVER GET IT WET' at some point.