Fresh, juicy pineapple can’t be beat. I could eat it all day, every day, but unfortunately, every time I try, I end up with a sore tongue and mouth — a stinging feeling. I decided to investigate why such a delicious food has such a terrible side effect. Most people think that it’s the acid from the fruit tearing up their mouth or that it’s the sign of an allergic reaction, but both of these explanations for the discomfort are probably incorrect. The irritation happens because pineapples contain bromelain, and enzyme that digests protein. The enzyme essentially attacks your tongue, cheeks and lips until it is swallowed. After that, your saliva and stomach acids both overtake the enzyme and denature it. When concentrated, bromelain is commonly used as a natural meat tenderizer, which explains a lot. Basically, your mouth = meat, and the pineapple is tenderizing (eating away at) your soft skin. This all sounds kind of scary,…