Have you ever seen a potato with a green tinge? Every once in a while we’ll open a new bag of potatoes and discover some with a pronounced green tint to the skin. Years ago a friend cautioned us to either pitch the potatoes in the compost or at least trim the green skin aggressively so that’s what we have always done. I never bothered to research the reason why we shouldn’t eat the green.
The green on a potato is not the healthy kind.
The green is actually chlorophyll but the process of greening also increases the amount of solanine in the potato and it’s the increase in solanine that makes a potato toxic. This over production of the toxin is produced by the potato when it has been exposed to light or warm temperatures, either in the field, in storage, at the grocery store or at home.
Why green potatoes are not safe to eat.
Potatoes naturally contain solanine in small amounts. It defends them from disease and pests and in a normal potato is harmless. In a green potato the solanine makes the potato taste bitter and can cause headaches, a burning throat, nausea, diarrhea, and neurological problems. According to food scientists, elevated solanine in one large baked potato is enough to make a 100 lb person ill.
Symptoms of solanine poisoning usually occur within 8-12 hours after ingesting toxic potatoes. Keep in mind that children are more susceptible to solanine poisoning since their smaller bodies can’t metabolize the compound as effectively.
What to do with green potatoes…
- Remove all of the green before cooking. That means cutting off the skin in thick slices any removing chunks if necessary.
- Solanine can also be elevated in normal looking potatoes if they have been exposed to warm temperatures. To be safe, if the cooked potato tastes bitter don’t eat it. (Solanine is not reduced by cooking.)
- Potato shoots are also high in solanine so pare generously around any sprouts before cooking the potato.
- Thin-skinned potatoes are more susceptible to greening. Eat them quickly rather than storing them.
- Examine red and blue skinned potatoes carefully before buying since the green tint may be harder to spot in potatoes with naturally coloured skin.
- Store potatoes in a cool, dark place.