Green on your potatoes? It’s more than just color and you might be serving a toxic meal without knowing

Saturday 25 October 2025 15:30 - Mirella Mendonça
Green on your potatoes? It’s more than just color and you might be serving a toxic meal without knowing

Have you ever picked up a potato from the pantry and noticed that it was starting to turn green? Your first reaction might be to cut off the colored part and use the rest as normal. But is this really safe?

Although it may seem like an aesthetic change, the green coloration of potatoes can indicate the presence of a toxic substance: solanine. And it can pose a real risk to your health.


Why do potatoes turn green?

The greenish hue appears when the potato is exposed to light for a long time. The light activates the production of chlorophyll, which is harmless in itself - but it also signals that the potato may be producing solanine, a natural compound that functions as the plant's defense against insects and fungi.

What is solanine and why is it dangerous?

Solanine is a toxin found in plants of the solanaceae family, such as potatoes, tomatoes and eggplants. In high concentrations, it can cause

  • Nausea
  • Vomiting
  • Diarrhea
  • Dizziness
  • In extreme cases, neurological disorders and even hallucinations

According to studies, , just 2 mg of solanine per kilo of body weight can cause mild symptoms. In other words, a seemingly small amount of contaminated potato can be enough to cause discomfort.

Does cooking eliminate solanine?

Unfortunately, no. Solanine resists heat, so frying, roasting or boiling the potato doesn't completely eliminate the toxin. Even if you peel the potato and remove the green part, there may still be residues of the substance in other areas.

When should I throw the potato away?

  • If the potato is very green on the outside and inside
  • If there are sprouts or signs that it is shriveled and old
  • If it tastes bitter after preparation

In these cases, the recommendation is clear: don't eat it. The risk, however small, is not worth it.

How to prevent potatoes from turning green?

  • Store potatoes in a dark, cool and dry place
  • Avoid leaving them in the fridge or exposed to light
  • Consume within the expiration date

Better safe than ill

Potatoes are part of millions of people's diets, but care should be taken with their storage and appearance. If you notice that a potato is green, don't risk it. If in doubt, it's best to discard it.

Your health is worth more than a potato.

Mirella MendonçaMirella Mendonça
I am the editorial manager at Petitchef (Portugal and Brazil) and a huge enthusiast of travel and world cuisine, always in search of new flavors and experiences. However, as much as I love exploring the delights of different cultures, my mom's cooking will always be my favorite — with that unique flavor that only she can create.

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