Peeling Large Quantities of Kiwi Can Make Your Fingerprints Disappear

In a previous post, I wrote about precautions when making kiwi distilled spirits. This time, I’d like to share an experience that happened during the process.

When I make kiwi distilled spirits, I typically use about 25 kg of kiwi at a time. I peel all the kiwis and crush them in a grinder. It’s a labor-intensive task, but during this process, I encountered an unexpected problem. I did the peeling by hand, and that turned out to be an issue.

After finishing the peeling and cleaning up, I noticed a persistent slimy sensation on my fingertips. Initially, I thought this was due to some slippery substance in the kiwis that clung to my fingers and didn’t wash off easily. I assumed it would eventually wear off, perhaps after taking a bath. But even after bathing, the sensation didn’t go away.

When my hands got wet, everything I touched felt unnaturally smooth. That’s when I realized something was off. Upon closer inspection, I noticed that my fingerprints had disappeared. My fingers had become completely smooth, and the lack of friction caused the slippery sensation when touching objects. Strangely, I didn’t notice this when my hands were dry, but it became very apparent when they were wet.

Why Do Fingerprints Disappear?

Kiwi contains a high amount of a protein-digesting enzyme called actinidin. The human skin is composed of approximately 57.5% water, 27.3% protein, and 14.2% fat. Protein-digesting enzymes break down proteins into amino acids, which means they can break down the protein in skin. When handling large amounts of kiwi with bare hands, this enzyme can potentially erode the ridges of your fingerprints, making them disappear temporarily.

About Kiwi’s Protein-Digesting Enzyme

Now that we know the power of kiwi’s actinidin, here’s some practical information you can use in daily life.

Protein is a vital nutrient for beauty, health, and immunity. By using kiwi’s protein-digesting properties, you can more efficiently absorb protein when consuming it alongside meat and other protein-rich foods.

Green kiwi contains 200–300 mg of actinidin per 100 g of fruit, which helps break down proteins in the digestive tract. Eating kiwi with meat, fish, dairy, or soy products can assist in digesting the protein. Kiwi can also be used in cooking: marinating meat or fish with kiwi breaks down the protein, tenderizing the flesh.

Scientific Evidence for Actinidin’s Effectiveness in the Stomach

While some have questioned whether actinidin can function effectively in the highly acidic environment of the stomach, studies have confirmed that it retains its protein-digesting ability in the stomach as well.

Other Fruits with Protein-Digesting Enzymes

Several other fruits are rich in enzymes that not only aid digestion but also tenderize meat when used in cooking. Here are a few examples:

Pineapple: Contains bromelain, which breaks down meat proteins and tenderizes it.
Kiwi: Contains actinidin, known for its meat-tenderizing and digestion-aiding effects.
Papaya: Contains papain, which is effective for tenderizing meat.
Mango: Contains protease, which enhances meat tenderness and aids digestion.
Fig: Contains ficin, which helps with digestion.

Marinating meat with these fruits before cooking results in softer, more flavorful dishes. Why not give it a try?