Why Fresh Pineapple Burns

by Annie Shao, age 19

When I felt my mouth and tongue burning after eating copious amounts of fresh pineapple, I panicked. What if I am allergic to one of my favorite foods? When will the tingling stop? As a biochemistry student, I guessed the burning might have been caused by natural acids in the fruit, but nature had me fooled.

It turns out that fresh pineapples contain bromelain, a mixture of two proteases, which are enzymes that break down proteins. It can be found all over the plant, but is most concentrated in the stem. Bromelain breaks down collagen, a long protein that binds together human and animal tissue. In other words, bromelain degrades your mouth’s cells.

But don’t panic, there is no reason to stop eating fresh pineapple. The amount of bromelain in pineapples can’t cause permanent damage because the human body will regenerate the broken-down cells. Bromelain also cannot harm the human digestive system because the enzyme will be denatured, or deactivated, by the strong acid in the stomach.

Bromelain is also used to tenderize meat. Meat, like the human tongue, has collagen that holds the muscle tissue together. This can make certain meats very tough and unpleasant to eat. Bromelain can be added prior to cooking to soften the meat. The high temperatures from cooking will denature the bromelain, which is why tenderized meat does not induce the same burning sensation that pineapple does.

But watch out—if the bromelain is left on the raw meat for more than a day, the meat will get too mushy to be edible. If you ask me, I’d take the collagen over mush.

Bromelain is also a widely used herbal medicine. People use it to reduce swelling, alleviate pain, and treat stomach problems. Some scientists even believe bromelain contains compounds that prevent growth of tumor cells and slow blood clotting.

To avoid the burning caused by eating pineapples, people opt for canned or cooked pineapples, which no longer contain bromelain. I would rather brave the proteases’ corrosive effects than give up the sweet, fragrant taste of fresh pineapple.

[Sources: howstuffworks.com; MedlinePlus]

Wow, great article! I wonder if this is why pineapple is so common as a meet marinade? I'll have to give it a try next time I cook some meat. – BenMadison (2014-05-20 20:22)
That kind of thiiknng shows you're an expert – MelloneyThat kind of thiiknng shows you're an expert (2016-07-19 23:39)