There are food safety concerns with growing, storing, preparing, and preserving potatoes. Find out how to handle them safely.
Potatoes are the most commonly consumed vegetable in the United States. According to the United States Department of Agriculture, 49.4 pounds of potatoes are consumed per person every year. It is also a popular vegetable to grow in a home garden. Potatoes are a great source of vitamin C, potassium and fiber and are a versatile plant that can be prepared in a variety of ways. As with any type of produce, there are some quality and safety considerations one should consider.
Growing and Harvesting
Potatoes are easy to grow in home gardens and even though it is tempting to plant potatoes that sprouted in your pantry, it is recommended to purchase certified seed tubers. By using certified tubers there is greater assurance that your crop will be virus and disease free, in addition to a more bountiful harvest. Potatoes grow well in sandy soil and are grown in a mound. There are some food safety considerations during the growing phase:
- Green potatoes: Have you ever heard that the green part of a potato is poisonous? The mound helps to keep growing potatoes covered from sunlight, which can lead to the formation of glycoalkaloids, a toxic compound. The type of glycoalkaloid found in potatoes is called solanine, and if enough of it is consumed, it can lead to vomiting, diarrhea, headaches, paralysis, coma and in rare cases, death. A small amount of green on a potato chip for example doesn’t necessarily equate to these symptoms. If you notice small spots of green on a potato, they can be trimmed off. If it covers a large area, discard the entire potato.
- Younger vs. older potatoes: Young, “new” potatoes are potatoes that are dug before their skins have grown thick. Many people like the tenderness of new potatoes, but they can be more susceptible to bruising, so handle carefully.
- Potato leaves: Potato leaves are toxic, so take care to remove them and do not eat them.
- Unharvested potatoes:Another question surrounding growing potatoes is if they are safe to eat if they were left in the ground over the winter. According to Oregon State University Extension, they are safe as long as they are disease free, firm and the skin is not green.
Storage
Model conditions for storing potatoes include dark, cool environments. Temperatures of 45-55 degrees Fahrenheit are ideal. Do not store raw potatoes in a refrigerator as temperatures are cooler than this (<40 degrees) and can facilitate the conversion of starch to sugar, resulting in an undesirable flavor. While newly harvested potatoes should be dried before storage, moist environments are best for storage. So, locations such as a root cellar or basem*nt can provide this desired humidity. However, for shorter term storage, a pantry is perfectly safe.
Some additional tips:
- Store potatoes in perforated plastic bags or an open bin, to allow for air flow.
- Do not store with onions, apples or other fruit as they produce ethylene gas which can promote sprouting.
- Do not rinse harvested potatoes before storing them, just brush the dirt off. Moisture can lead to rot, so rinse them just before you use them.
Preparing
If you notice that your potato has sprouted, how do you know if it is safe to eat it? As long as the potato is firm, not soft or shriveled and the sprouts are small, you can remove the sprouts and safely consume the rest of the potato. The sprouts and the potato plant contain the toxin solanine, so the consumption of the potato sprouts or plant is not recommended.
First, wash the potatoes under lukewarm, running water and scrub the skin with a vegetable brush. Prepare the potatoes according to your recipe. Once potatoes have been cooked, they need to be cooled and stored in the refrigerator at 40 degrees or lower within two hours. Due to the heat and moisture that have been introduced through cooking, the potato becomes a potentially hazardous food and should be kept out of the danger zone (40-140 degrees Fahrenheit). Foil wrapped baked potatoes are of particular danger of botulism illness and have been associated with foodborne outbreaks. Remove foil before storing in the refrigerator.
Preserving
Potatoes are a low-acid food, and thus they must be processed using a pressure canner when home canning. You may use either a weighted gauge or a dial gauge pressure canner. If you are using a dial gauge canner, be sure to have your dial gauge tested annually for accuracy. Although it is safe to can cubed or sliced potatoes, it is NOT safe to can mashed or pureed potatoes. It is critical to follow research-tested guidelines and recipes when canning foods at home for safety as well as quality. In addition to canning, potatoes can also be safely frozen, but generally this is not preferred because the water separates from the starch, and results in a poor-quality product. For full canning and freezing instructions, see our Michigan Fresh: Using, Storing, and Preserving Potatoes factsheet.
For more information on how to safely preserve food at home, check out our Preserving MI Harvest series every Thursday at 1 p.m. and 6 p.m. EST.
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FAQs
Once potatoes have been cooked, they need to be cooled and stored in the refrigerator at 40 degrees or lower within two hours. Due to the heat and moisture that have been introduced through cooking, the potato becomes a potentially hazardous food and should be kept out of the danger zone (40-140 degrees Fahrenheit).
How to tell if potatoes are safe to eat? ›
Raw potatoes should be firm to the touch with tight skin that's free of large bruises, black spots, or other blemishes. If a potato has become soft or mushy, you should throw it out. Though it's normal for potatoes to smell earthy or nutty, a musty or moldy odor is a hallmark of spoilage.
How do I make sure potatoes are safe to eat? ›
3 ways to prevent potato-related food hazards
- Cool off. Cooling potatoes properly is the best way to avoid a foodborne illness outbreak. ...
- Serve safely. If cooked potatoes are being reheated, make sure they reach at least 165°F. ...
- If in doubt, throw it out!
What is the foodborne illness in potatoes? ›
Perhaps the most concerning consequence of cooling a baked potato improperly is the potential growth of Clostridium botulinum, which is a group of bacteria that can cause botulism. Botulism is a serious illness that can lead to paralysis and even death if left untreated.
Are cooked potatoes safe to eat? ›
Cooked potatoes and other cooked vegetables can be safely kept in the refrigerator 3 to 4 days.
When shouldn't you eat a potato? ›
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.
What is the danger zone for potatoes? ›
Due to the heat and moisture that have been introduced through cooking, the potato becomes a potentially hazardous food and should be kept out of the danger zone (40-140 degrees Fahrenheit). Foil wrapped baked potatoes are of particular danger of botulism illness and have been associated with foodborne outbreaks.
Is it okay to eat potatoes that are sprouting? ›
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.
Are slightly soft potatoes safe to eat? ›
But what if they're just a little soft, or have a few sprouts? As long as the potatoes are still mostly firm, they're fine to cook. Potatoes are 80 percent water, so softness is usually just a sign of dehydration. But if they're extremely mushy or shriveled, do not pass go.
How common is solanine poisoning? ›
Because of the bitter taste and appearance of such potatoes, solanine poisoning is rare outside conditions of food shortage.
As mentioned above, commercially available potatoes hardly ever cause food poisoning.
Can you explain why reheating potatoes can make them harmful to eat? ›
Even though a popular food item, it isn't too safe to reheat potatoes. A bacteria called Clostridium botulinum that releases a toxic chemical would be grown if cooked potatoes are kept at room temperature for longer. So, leftover potatoes should be stored in the fridge.
Why are mature potatoes toxic? ›
Potatoes contain two toxic glycoalkaloids called solanine and chaconine. However, fresh potatoes that have not sprouted contain only small amounts of glycoalkaloids at concentrations that are safe for consumption. Exposure to light greatly increases the formation of chlorophyll and glycoalkaloids.
Is it safe to eat potatoes with black spots inside? ›
Are they OK to eat? A: Black spots in potatoes are mostly attributed to internal bruises or the result of sugar concentrations brought on by any of several pre or post-harvest conditions and are generally harmless. However, the black spots could also be an early concentration of decay.
Why shouldn't cooked potatoes be refrigerated? ›
Higher acrylamide levels
Refrigerating boiled potatoes and then reheating them can elevate acrylamide levels.
What is the healthiest way to cook potatoes? ›
Steaming And Air Frying Are The Healthiest Ways To Cook Potatoes. Despite popular claims, potatoes can be an amazing source of fiber and nutrients so they're beneficial for losing or maintaining a healthy weight.
Can I eat potatoes that have sprouted? ›
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.
How do you know if a potato is poisonous? ›
The poison is found throughout the plant, but particularly in green potatoes and new sprouts. Never eat potatoes that are spoiled or green below the skin. Always throw away the sprouts. Potatoes that are not green and have had any sprouts removed are safe to eat.
When should you throw out potatoes? ›
If the green tint on your taters is light and mostly skin-deep, peel them well to remove the green parts and go forth. But if they're starting to look like post-transformation Fiona, it's time to pitch 'em. Same goes for potatoes that have gone mushy or wrinkly—those are tell-tale signs of spoilage.
How long should it take for potatoes to go bad? ›
Shelf life of potatoes
Preparation and storage temperature | Shelf life |
---|
Raw, stored at around 50°F/10°C | 2–3 months |
Raw, stored at around room temperature | 1–2 weeks |
Cooked and refrigerated | 3–4 days |
Cooked and frozen | 10–12 months |
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