The key facts

  • Cutting off the green area of a greened potato does not guarantee removal of solanine — the toxin can spread deeper into the tuber
  • Boiling and frying only partially reduce the amount of solanine but do not destroy it completely
  • The toxic dose for an adult is approximately from 50 mg of solanine, for a child from 15–40 mg

Cutting off the green side does not make a potato safe

You should not eat greened potatoes even after removing the green part: the common belief that it is enough to cut off the green side is a myth. This was stated to Gazeta.Ru by Alexander Sysuev, a lecturer at the Department of Biotechnology and Industrial Pharmacy at RTU MIREA. According to him, the green color on a tuber is a signal that solanine, a natural toxin that protects the plant from pests and diseases, has accumulated in that spot.

Why cutting it out does not help and what experts advise

The problem, the chemist explained, is not limited to the green patch: solanine is concentrated mainly in the peel, sprouts and eyes, and can also spread deeper into the tuber, so simply cutting out the damaged area does not guarantee complete removal of the toxin. Heat treatment does not solve the issue either — boiling and frying only partially reduce the amount of solanine but do not eliminate it.

Doses and signs of a dangerous tuber

The toxic dose for an average adult starts at approximately 50 mg of solanine, and for a child at 15–40 mg. In greened areas the concentration can be very high, so even a small portion of such potatoes can cause nausea, vomiting, diarrhea and abdominal pain. At the same time, according to Sysuev, some experts allow cutting out the damaged area with a margin if the green patch is small and the tuber is firm, without sprouts or signs of rot. However, if the greening is pronounced, large sprouts have appeared, the tuber has become soft, wrinkled or has developed an unpleasant smell, such potatoes should be discarded without hesitation.