Why sprouted potatoes should be kept at bay?

Potatoes are everywhere when it comes to Indian cuisine. These stem tubers are used to make tangy curries, crispy fries, masala fillings and whatnot. They also pack a healthy punch with a decent amount of starch, vitamins, minerals and fibre. But the question that is raised time and again—is it safe to eat sprouted potatoes, that too with green spots? Studies have shown that the presence of natural toxins in sprouted potatoes with a green hue is not deadly but the consumption of such spuds in large quantities can result in poisoning and make you sick. The usual brown skin of the potato gets a greenish tinge when they are exposed to sunlight. And the reason is quite simple. The plants get their green colour because of the presence of a pigment called chlorophyll. When the potato sprouts or is exposed to sunlight, chlorophyll is produced resulting in the green colour.

Chemicals in potatoes
Along with chlorophyll, certain other chemicals, which are collectively known as glycoalkaloids, are also found in potatoes. Two types of glycoalkaloids – solanine and chaconine—are present in potatoes in small quantities and both act as a protective mechanism to ward off pests. But when potatoes sprout or have green spots, there is a marked increase in alkaloids, which is detrimental to one’s health. The high concentration of alkaloids in the leaves of potato plants makes them inedible. The Journal of Family Medicine and Primary Care in 2022 reported a case of solanine poisoning, which had its origin from potatoes, in an 11-year-old child in Saudi Arabia. It is worth noting that there have been no reports to date of glycoalkaloids in potatoes causing human deaths. However certain studies have proved that glycoalkaloids can adversely affect the nervous system.

As many as 78 children were admitted to hospital after consuming potatoes with high solanine in London in the 1970s. However, prompt medical treatment helped them to regain health. The permissible level of glycoalkaloids in potatoes is 20mg for 100g. The potatoes with a greenish skin will have 100mg of glycoalkaloids for 100g. When the skin is peeled off, the presence of glycoalkaloids will dip to 0.10 - 4.50mg for 100g. Ensure not to mix potato shoots with food as glycoalkaloids are very high in them. If possible, avoid potatoes with green spots. If you want to use them, chop off the shoots peel off the skin completely and wash them thoroughly. Make sure you store potatoes away from sunlight.