There’s a rumor circulating online that “green potatoes are poisonous,” but this isn’t true. Potatoes appear green because they produce chlorophyll when exposed to light. The green part contains alkaloids, but the amount is likely lower than what’s found in sprouted potatoes. So, can green potatoes still be eaten?

Why do potatoes turn green? Are they poisonous?

Edible potato tubers produce chlorophyll when exposed to light. Potatoes may also turn green in small areas during planting if they aren’t planted deep enough, exposed to sunlight.

The green part begins to produce toxic alkaloids, but the depth of the green color can’t be used to determine the alkaloid content of the entire potato.

Glycoalkaloids are naturally occurring components of potato tubers and are secondary plant metabolites, commonly found in the Solanaceae family. For example, in potatoes, tomatoes, and eggplants, it has insecticidal and fungicidal properties, helping plants resist damage from animals, insects, and fungi.

So, can green potatoes be eaten? It depends on the alkaloid content.

α-Solanine is the main glycoalkaloid in potatoes. Generally, the content is 30-100 mg/kg. However, it can increase to 5 g/kg in sprouting areas or areas that turn green when exposed to light. Eating such potatoes is likely to cause discomfort in healthy individuals.

When the alkaloid content in potatoes exceeds 200 ppm, symptoms of acute poisoning may occur, such as nausea, headache, and abdominal pain. In severe cases, hemolysis and shortness of breath may occur.

Therefore, whether a potato has sprouted or has a green skin, if you really want to cook it, remove the area around the sprout and any green areas before cooking. However, solanine can taste bitter and stinging.

If you’ve removed the sprouts and green areas from your potatoes and they still taste like these, avoid eating them to avoid poisoning.

How should potatoes be stored? Keep them cool and out of direct sunlight.

Don’t assume that heating destroys solanine. That’s not true. Normal cooking temperatures won’t eliminate it. Therefore, the best approach is to store potatoes properly and eat them fresh to prevent them from sprouting or turning green.

When choosing potatoes, choose ones that have been well-stored, have an intact, clean surface, feel firm and smooth, and have no sprouts. After purchase, store them cool and out of direct sunlight or for extended periods. If potatoes sprout, it’s recommended not to eat them to prevent toxic alkaloids like solanine from entering the body.