Potatoes are a staple food in many cultures and have been enjoyed for over 10,000 years (1).
Besides being rich in potassium, they are a great source of carbohydrates and fiber (2).
These tasty tubers can be prepared in many ways, but they are usually baked, boiled, roasted, fried or dehydrated.
Proper storage can prolong its useful life and avoid unnecessary waste.
This article reviews the best storage techniques and includes tips for selecting the freshest potatoes.
Store raw potatoes in a cool place
The storage temperature has a significant impact on the duration of the potatoes.
When stored between 43-50 ° F (6-10 ° C), raw potatoes will remain for many months without spoiling (3).
This temperature range is slightly warmer than cooling and can be found in basements, basements, garages or cool sheds.
Storing potatoes in these conditions can help delay the formation of skin flares, one of the first signs of deterioration.
In fact, one study found that storing potatoes at cool temperatures more than quadrupled their shelf life, compared to storing them at room temperature (3).
Storage at lower temperatures also helps preserve its vitamin C content.
The research showed that potatoes stored at cold temperatures kept up to 90% of their vitamin C content for four months, while those stored in warmer temperatures lost almost 20% of their vitamin C after one month (3, 4 ).
Storing at temperatures slightly above cooling is an excellent way to extend shelf life and maintain vitamin C content.
Summary Storing the potatoes in a cool place helps to reduce the sprouting rate and maintains its vitamin C content.
Stay away from light
Sunlight or fluorescent light can cause potato skin to produce chlorophyll and acquire an undesirable green color (1).
While the chlorophyll that makes the skins green is harmless, exposure to the sun can produce large amounts of a toxic chemical called solanine.
Many people throw away green potatoes because of their higher levels of solanine (5).
Solanine creates a bitter taste and causes a burning sensation in the mouth or throat of people sensitive to it (6).
Solanine is also toxic to humans when consumed in very high amounts and can cause nausea, vomiting and diarrhea. Some cases of death have even been reported (7).
However, many countries have mandatory guidelines that limit the amount of solanine in commercial potatoes to less than 91 mg per pound (200 mg / kg), so it is not a common concern (8, 9).
Solanine is found almost exclusively in the skin and in the first 1/8 inch (3.2 mm) of the meat. If the skin and the underlying green flesh are peeled, most of it can be eliminated (5).
Summary Storing potatoes in the dark prevents them from turning green and developing a high content of solanine, which can cause nausea, vomiting and diarrhea when consumed in large quantities.
Do not store raw potatoes in the refrigerator or freezer
While cold temperatures are ideal for storing potatoes, refrigeration and freezing are not.
Very low temperatures can cause "cold-induced sweetening". This happens when part of the starch is converted into reducing sugars (10).
The reduction of sugars can form carcinogenic substances, known as acrylamides, when they are fried or exposed to very high cooking temperatures, so it is better to keep the levels low (11, 12).
Uncooked potatoes should never be stored in the freezer.
When exposed to freezing temperatures, the water inside the potatoes expands and forms crystals that break the structures of the cell wall. This makes them soft and unusable when defrosted (13).
Raw potatoes can also turn brown when exposed to air in the freezer.
This is because the enzymes that cause browning are still active in potatoes, even at freezing temperatures (14).
It is good to freeze them once they are totally or partially cooked, since the cooking process deactivates the golden enzymes and prevents them from discolouring (15).
Summary Raw potatoes should not be kept in the refrigerator, since cold temperatures increase the amounts of reducing sugars and make them more carcinogenic when fried or roasted. Neither should they freeze, as they will become soft and brown after thawing.
Place in an open container or paper bag
Potatoes need air flow to prevent the accumulation of moisture, which can lead to deterioration.
The best way to allow free air circulation is to store them in an open container or in a paper bag.
Do not store them in a sealed, unventilated container, such as a zippered plastic bag or glassware with a lid.
Without air circulation, the moisture released from the potatoes will accumulate inside the container and promote the growth of mold and bacteria (16).
Summary To help your potatoes last longer, store them in an open container, a paper bag, or another container with ventilation holes. This helps prevent the accumulation of moisture, which leads to it spoiling.
Do not wash before storing
As potatoes are grown underground, they often have dirt on their skin.
While it may be tempting to rinse the dirt before storing it, it will last longer if you keep it dry.
This is because washing adds moisture, which promotes the growth of fungi and bacteria.
Wait until you are ready to use them, then rinse and rub them with a vegetable brush to remove the remaining dirt.
If pesticides are a concern, rinsing with a solution of vinegar or 10% salt can eliminate more than twice as much waste as water alone (17).
Summary Potatoes will last much longer if they remain dry during storage and do not wash until they are ready to be used. Washing with a salt or vinegar solution can help eliminate more pesticide residues than water alone.
Stay away from other products
Many fruits and vegetables release ethylene gas as they mature, which helps to soften the fruit and increase its sugar content (18).
If stored nearby, mature products can cause raw potatoes to sprout and soften more quickly (19).
Therefore, do not store potatoes near ripe fruits and vegetables, especially bananas, apples, onions and tomatoes, since they release relatively large amounts of ethylene (18).
While no study has looked at the extent to which potatoes should be prevented from ripening fruits or vegetables, storage at the opposite ends of a cool, dark, well-ventilated pantry is probably effective.
Summary Store potatoes away from ripe products, especially bananas, tomatoes and onions, since the ethylene gas they release can cause potatoes to germinate more quickly.
Cure home grown potatoes before storing
Most people buy potatoes in their local market, but if you grow your own, "cure" them before storing them will prolong their useful life.
The curing consists of storing at moderately high temperatures, generally around 65 ° F (18 ° C) and humidity levels of 85 to 95% for two weeks.
You can use a small dark cabinet or an empty shower with a space heater and a container of water, or an empty oven that is slightly open, lit with a 40-watt bulb for heat and a container of water for moisture.
These conditions allow the skins to thicken and help heal any minor injuries that may have occurred during harvest, reducing the chances of deterioration during storage (20).
Cured potatoes can be kept in a cool, dark place with good ventilation for long-term storage.
Summary Freshly harvested potatoes should be "cured" at higher temperatures and with high humidity for a few weeks to allow the skin to thicken and the spots to heal. This helps extend your storage life.
Store raw slices in water for up to a day
Once peeled and cut, raw potatoes fade quickly when exposed to air.
This is because they contain an enzyme called polyphenol oxidase, which reacts with oxygen and makes the meat a gray or brown color.
You can avoid discoloration by covering the peeled and cut slices with one or two inches of water and refrigerating them until you are ready to use them (1).
The water protects them from the air and prevents enzymatic browning.
However, if left in the water for more than 24 hours, they can absorb too much water and become soggy and tasteless. Only use this technique for potatoes that will be cooked on the same day.
For longer storage, consider vacuum packaging, a technique in which all air is removed from a container and sealed tightly.
Vacuum-packed potatoes will last up to a week in the refrigerator (21).
Summary Raw potatoes turn brown or gray when exposed to air, so they should be cooked quickly or stored in water until ready to use. If you keep them for more than a day after preparing them, remove them from the water, vacuum them and store them in the refrigerator.
Store cooked leftovers in the refrigerator for three or four days
Cooked potatoes will last several days in the refrigerator.
However, leftovers can become watery or rubbery, since potato starches change shape and release water when cooled (22).
Cooking and cooling also increase the formation of resistant starch, a type of carbohydrate that humans can not digest and absorb.
This can be good for those with blood sugar problems, since it reduces the glycemic index by about 25% and causes a much smaller increase in blood sugar after eating (23, 24).
Resistant starch also promotes intestinal health, since intestinal bacteria ferment it and produce short-chain fatty acids, which help keep the lining of the large intestine healthy and strong (25, 26, 27).
Although cooked and cooled potatoes have some health benefits, they should be eaten within three or four days to avoid spoilage and food poisoning (28).
Summary Cooked potatoes can be stored in the refrigerator for up to four days. The cooling process increases the formation of resistant starch, which has a lower impact on blood sugar levels and promotes the growth of healthy intestinal bacteria.
Store cooked leftovers in the freezer for up to one year
If you do not plan to eat cooked potatoes in a few days, it is best to keep them in the freezer.
Cooked leftovers can be stored in the freezer without browning, since cooking destroys the enzymes responsible for discoloration (15).
Like all frozen products, leftover potatoes will last longer if they are protected from the air while in the freezer.
Use a plastic bag or storage container and press all the air to remove it.
Research shows that frozen and cooked potato products can last up to a year without significant changes in quality (13).
When ready to eat, let them thaw in the refrigerator overnight before heating and serving. This results in a better texture than thawing in a microwave (29).
Summary The remaining cooked potatoes can be stored in the freezer for up to one year. Store in airtight containers to preserve quality and thaw overnight in the refrigerator before use.
Tips for selecting the best potatoes
Potatoes will last longer if they are fresh and healthy when purchased.
When selecting, look for the following features:
- Firm to the touch: The soft potatoes have already begun to degrade, so look for firm and bright qualities.
- Soft skin: Potatoes that have been damaged by cold temperatures can develop skin with brown holes and centers, so look for soft textures.
- Free of bruises or injuries: Sometimes potatoes can be damaged during harvest or transportation. Avoid people with visible injuries, because they will be lost more quickly.
- They do not sprout Outbreaks are one of the first indicators of deterioration, so avoid buying any that have already sprouted.
You may also consider trying some of the more exotic varieties of potatoes, such as those with blue or purple flesh.
Studies show that varieties of vibrant colors contain much higher amounts of antioxidants than traditional white potatoes (30).
Summary Fresh and healthy potatoes last longer, so look for soft, firm ones without spots or buds. Consider trying blue or purple varieties, as they contain high levels of antioxidants.
The bottom line
Knowing the best ways to store potatoes can prolong their shelf life and reduce food waste.
Store uncooked potatoes in a cool, dark place with plenty of air circulation, not in the refrigerator.
Prevent the cut and peeled slices from browning by covering them with water or vacuum sealing.
Cooked potatoes can be kept in the refrigerator for up to four days, or in an airtight container in the freezer for up to one year.
When it comes to home-grown potatoes, cover them briefly at warmer temperatures and high humidity before long-term storage.
Regardless of the storage method, potatoes will last longer if they are fresh and healthy when purchased, so look for firm, smooth, flawless tubers with no signs of outbreaks.
Reference: https: //www.healthline.com/nutrition/how-to-store-potatoes