Green is not a good thing when it comes to potatoes.
What causes potatoes to turn green — and are they safe to eat?
Light exposure can cause a potato’s skin cells to produce chlorophyll. The chlorophyll then causes the skin to turn green and helps the potato get ready to sprout. Light also activates the skin cells to produce solanine, a glycoalkaloid toxin, which has a bitter taste.
Throughout this process, a second toxin formed is chaconine. According to Poison.org, the two toxins can cause abdominal pain, diarrhea, vomiting, irregular bowel movements, headache, redness or flushing of the complexion, brain fog, confusion, disorientation and fever. Therefore, you should avoid eating green-skinned potatoes to avoid causing these symptoms.
While few people will eat enough of the bitter-tasting green potato to make themselves sick, Michigan State University Extension still recommends throwing green-skinned and sprouted potatoes away to prevent possible gastrointestinal upset caused by solanine and chaconine. The symptoms are likely to begin within a few hours of eating the green potatoes, but symptoms may sometimes occur a full day or two after eating green potatoes.
When purchasing potatoes from the farmer’s market or grocery store, check them, avoiding any green-colored, shriveled or sprouted potatoes. These are signs of poor quality.
Potatoes must also be stored in a cool, dark, dry location, preferably between 45 and 50 degrees Fahrenheit. The storage location should be well ventilated. With these storage recommendations, the potatoes should remain at their best quality for about a month.
When preparing potatoes for cooking and eating, trim away any small green spots and sprouts or eyes. Do not use green potatoes, trimmed or not, if you have small, young children; they are more susceptible to solanine poisoning due to their small body mass.
An excellent resource with guidelines for how long you can store food is the U.S. Department of Agriculture (USDA) Food Keeper App available online or as a download from your smartphone app store. For best quality and food safety reasons, only purchase enough food that your household will eat in a reasonable amount of time, whether you are storing it in the pantry, freezer, or refrigerator. Use a rotation system called FIFO (first in, first out) in your pantry, so the older products are used up first.
For food safety questions, you can also contact the Michigan State University Extension Food Safety Hotline at 877-643-9882. The hotline is available Monday through Friday, from 9 AM to 5 PM EST.
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FAQs
To be safe, it is best to not eat the green part of tubers." You do not need to discard green potatoes. Just peel the skins, shoots and any green color; that is where the solanines concentrate. The United States Department of Agriculture's Food Safety and Inspection Service inspects only meat, poultry and egg products.
Can you eat potatoes with a green tinge? ›
While few people will eat enough of the bitter-tasting green potato to make themselves sick, Michigan State University Extension still recommends throwing green-skinned and sprouted potatoes away to prevent possible gastrointestinal upset caused by solanine and chaconine.
What to do with green potatoes? ›
Green potatoes should be prepared carefully. Although the green color itself is not harmful, it may indicate the presence of a toxin called solanine. Peeling and trimming green potatoes can help reduce solanine levels. If a potato is green throughout or your potato dish tastes bitter, it's best to throw it away.
What happens if you accidentally eat a green potato? ›
Solanine is considered a neurotoxin, and ingestion by humans can cause nausea and headaches and can lead to serious neurological problems and even death if enough is consumed. A recent study suggested that a 16-oz (450-gram) fully green potato is enough to make a small adult ill.
Why do potatoes turn green? ›
When potatoes are exposed to light, they start undergoing photosynthesis and converting those nutrients into energy. Photosynthesis triggers the production of chlorophyll, and the potato turns green. Unfortunately, this process also creates solanine, a poison that can be dangerous if it's ingested in large quantities.
Why does potato turn green on passing current? ›
This process release electrons in potato and increase the negative particles. When these negative particles reach the other end of copper, it reacts with a part of Cu wire inside potato and makes a complex which is green in colour. Hence it becomes green on passing electricity.
Can you eat potatoes with green growth? ›
A potato that has grown eyes is still safe to eat so long as it's firm to the touch and its skin isn't shriveled. Sprouts, however, are not edible and should be removed and tossed.
Can solanine be destroyed by boiling green potatoes? ›
Solanine is not removed by boiling, but it can be destroyed by frying. Solanine poisoning is uncommon as cooks and the public are aware of the problem and tend to avoid green potatoes, in any case, consumption of up to 5 g of green potato per kg body weight per day does not appear to cause acute illness.
Are sprouted potatoes safe to eat? ›
Sprouted potatoes that are still firm, have relatively small sprouts, and don't show any wrinkles or shriveling are okay to eat, as long as you cut off the sprouted parts and soft spots. However, there's still a chance you could get sick. If your potato is sprouted and shriveled up, then it's too far gone. Toss, it.
Can green potatoes cause food poisoning? ›
Despite their nutritional value, potato tuber may harm human health by virtue of their toxic glycoalkaloids (solanine). Acute solanine poisoning can happen from ingesting green or sprouted potatoes. The toxicity of Gas in humans causes mainly gastrointestinal disturbances such as vomiting, diarrhea, and abdominal pain.
CONSTITUTION: Solanin is removed from potatoes by dipping the potatoes in vinegar of 30-60 deg. C, containing 0.3-1.0 vol% of acetic acid, for 2-5 minutes.
When not to eat potatoes? ›
As they age, or with improper storage, potatoes may develop sprouting and green spots. If there isn't any sprouting, you can use the color change as an indicator of spoilage. If the skin looks greenish or if there's sprouting present, you'll need to remove the sprouts or toss the whole potato, depending on severity.
Are potatoes with a green tinge OK to eat? ›
Consequently, it is important to store potatoes in the absence of light to prevent greening. Tubers with a high concentration of solanine will taste bitter, and can be harmful if eaten in large quantities. To be safe, it is best to not eat the green part of tubers." You do not need to discard green potatoes.
How do you get rid of green on potatoes? ›
Removing the green portions by simply cutting them out will eliminate most of the toxin. However, if more extensive greening occurs, throw the tuber away. Never eat tubers that are green beneath the skin.
When should you throw out potatoes? ›
Potatoes that are soft, mushy, squeezable, or moist are past their prime. "If you cut into a potato and it looks green or brown throughout, you should throw your potatoes away," said Silness. If it's just a few blemishes, those can be trimmed off, and the potato can be salvaged.
Is solanine destroyed by cooking? ›
Solanine is not removed by boiling, but it can be destroyed by frying. Solanine poisoning is uncommon as cooks and the public are aware of the problem and tend to avoid green potatoes, in any case, consumption of up to 5 g of green potato per kg body weight per day does not appear to cause acute illness.
How to stop potatoes from going green? ›
To keep tubers from turning green, avoid exposing them to light. When purchasing potato tubers, check for green coloring before purchasing them. You can prevent potatoes from turning green by storing them in a cool, dark area with good air circulation and high humidity.
