Many people who enjoy fresh pineapple have experienced the strange sensation it can cause: a tingling or raw feeling on the tongue, lips, and inside of the mouth. For those who cut the fruit, a similar phenomenon can occur on the hands, leaving the skin on the fingertips feeling unusually smooth, as if the prints have been temporarily erased. The experience is not an allergic reaction for most, but a direct result of the fruit’s chemical composition interacting with your body.
The Chemical Behind the Sensation
The tingling and soreness are caused by a complex of enzymes called bromelain. Found in the pineapple’s fruit and stem, bromelain is a protease, an enzyme that breaks down proteins. When you eat fresh pineapple, the bromelain begins to act on the protein-rich tissues lining your mouth, including your tongue and cheeks.
This process is also why pineapple is used as a meat tenderizer; the bromelain breaks down the tough proteins in the muscle tissue. The same action that softens a cut of meat is what causes the temporary irritation and the feeling of smoothed-out fingerprints, as the enzyme digests the outer layer of skin cells. The cells in your mouth and on your skin regenerate quickly, so the sensation does not last long. The combination of bromelain and the fruit’s natural acidity likely intensifies this effect.
A Plant’s Natural Defense
The reason pineapples contain this potent enzyme mixture is not for the benefit of humans, but for the plant’s own survival. Bromelain functions as an effective natural defense mechanism. It serves to protect the pineapple plant from agricultural pests and insects that would otherwise feed on the sweet, ripening fruit.
This enzymatic defense creates an irritating or harmful effect on the pests, discouraging them from consuming the plant tissue. In addition to bromelain, pineapples contain microscopic, needle-shaped crystals called raphides, which are made of calcium oxalate. These tiny needles can physically prick the lining of a predator’s mouth, working with bromelain to create an unpleasant experience that protects the fruit.
How to Prevent the Tingling Feeling
For those who enjoy the taste of pineapple but not the accompanying discomfort, there are several methods to neutralize the bromelain:
- Apply heat by cooking, grilling, or blanching. This denatures the enzymes, which is why canned pineapple, heated during its canning process, does not cause the same tingling sensation.
- Soak the cut fruit in a saltwater solution before eating. The salt helps to activate the bromelain, causing the enzyme to exhaust itself before it comes into contact with your mouth.
- Pair fresh pineapple with dairy products like yogurt or ice cream, as the bromelain will act on the milk proteins instead of the ones in your mouth.
- Remove the core of the pineapple to reduce your exposure, as the bromelain is most concentrated in that part of the fruit.