Have you ever noticed that your tongue and lips feel slightly sore or burned after eating a large amount of fresh pineapple? This is not just the acidity of the pineapple causing this sensation โ there is a much more interesting scientific reason.
Pineapple contains bromelain, a group of highly active protease enzymes (enzymes that digest protein). Bromelain is not only found in the flesh of the pineapple but also in the stem, leaves, and skin. When you eat fresh pineapple, bromelain starts to digest the protein in the mucous membranes of your mouth, tongue, and gums โ literally starting a digestive process earlier than usual.
Bromelain is a very useful enzyme in the food industry. It is used to tenderize meat because it breaks down collagen and muscle proteins. Baking with fresh pineapple (not canned pineapple) as a decoration will not set properly because the bromelain in the fresh pineapple will digest the gelatin and proteins in the cake. Canned pineapple does not have this issue because the heating process during canning destroys the enzyme.
Bromelain also has interesting medical uses. It is used in supplements to reduce inflammation, aid in protein digestion, and in some studies, it has shown potential anti-cancer properties. In the industrial world, bromelain is used in leather tanning, textile production, and various biochemical industrial processes.
When you eat pineapple, there is an interesting race: whether your enzymes digest the pineapple first, or the bromelain in the pineapple digests you first. In practice, you win because bromelain is destroyed by stomach acid before it can do much damage.