Why do peeled potatoes turn black? Why do potatoes turn black and how to deal with it? Storage and ventilation

Potatoes have long occupied a leading position on the everyday and holiday tables. It is served as an independent dish and used as an ingredient. In order for the side dish to look appetizing, you need to know why potatoes turn black after cooking and what needs to be done to avoid this.

How to cook potatoes?

The product must be washed and cleaned before cooking. It is better to put potatoes in salted and hot water, rather than in cold water. This way the product will save more vitamins and nutrients. The liquid in which the potatoes were boiled can be used to prepare vegetarian soups and infusions.

If you cook it “in its uniform”, the dish will be much healthier. But it should be borne in mind that the glycoside solanine is present on the surface of the tubers and in the peel - this is a poisonous and bitter substance. If the potatoes are sprouted, they must be thoroughly peeled. In the case where the product grows in fertilized soils, after cleaning it should be kept in cold water for about half an hour.

Why do potatoes turn dark?

Probably every housewife has thought about why it turns black. The reason for this is chemical in nature. The tubers contain the amino acid tyrosine, which begins to oxidize and form the pigment melanin. It is this that colors the potatoes dark.

On an industrial scale, this problem is solved with the help of sulfur dioxide (sulfur dioxide), which is used to treat the product. This substance has restorative properties. At home, you can immerse the potatoes in boiled water and cover the container with a lid to prevent oxygen from entering.

How to avoid potatoes being too soft?

When cooked, potatoes become soft due to the fact that the polymer molecules of protopectin are destroyed and converted into molecules of pectin, which is soluble. At the same time, magnesium and calcium cations are removed from the tubers. If so, this process is much slower. Therefore, potatoes must be added to dishes before sour seasonings and foods, otherwise they will remain uncooked and tough.

How to determine which potatoes will turn black?

In trying to find the answer to the question of why potatoes turn black after cooking, you need to have an idea of ​​the reason for this phenomenon. The browning after cooking is different from that which occurs on the raw product. There is a method that allows you to determine which tubers will turn black. To do this, you need to treat the potatoes with a solution of sodium nitrate, to which diluted hydrochloric acid has been added, and then lubricate it with sodium hydroxide. Within a few minutes, the treated area will begin to turn red.

Are browned potatoes dangerous?

Housewives are interested not only in why potatoes turn black when cooked, but also whether they are dangerous to health. Experts say that such a product can be safely eaten.

Gardeners recommend maintaining the correct proportions of fertilizers. Synthesis may be disrupted if there is a large amount of nitrogen, but little potassium. This will lead to the accumulation of proteins and amino acids. Therefore, it is worth taking care of a sufficient amount of potassium.

To avoid darkening, you need to keep the potatoes in a cool, dry place until frost sets in. Then the tubers will have time to dry and cool. If you immediately place the product in the basement, physiological changes will occur and the tubers will darken during cooking. In the event that this is impossible to do for some reason, you need to keep the potatoes in cold water for some time before cooking.

Storage and ventilation

To understand why potatoes turn black after cooking, it will be useful to know the rules for storing them. Darkening can be caused not only by over-compacted soil, but also by insufficient ventilation during storage. This leads to the fact that the potatoes do not have enough air, and they begin to “suffocate”. To avoid this, you need to regularly ventilate the room and carefully inspect the vegetables that are there. You cannot store food that has begun to rot or is damaged.

Temperature and humidity also matter. Perspiration can cause rapid mold growth, which consumes oxygen. All wet tubers should be dried thoroughly.

Harvesting and transportation

The answer to the question of why potatoes turn black after cooking may be non-compliance with harvesting and transportation rules. When collecting potatoes, you should not throw them away and allow them to get damaged. When storing, it is very important to ensure that conditions are always optimal.

How to cook frozen potatoes?

If the product is frozen, it must be defrosted in cold water. When an ice crust forms around the potatoes, you need to change them and add a little salt.

To make it easier to peel potatoes in their jackets, after boiling you need to pour cold water over them.

Secrets of cooking boiled potatoes

Experienced cooks advise adding a little vinegar to the water while cooking potatoes. This will not only prevent darkening, but will also help prevent the product from overcooking.

Jacket potatoes will not boil if you add a little more salt to the water than is required for normal cooking.

Those that are considered mealy often become very boiled, so you should add brine from cucumbers or cabbage to the water, and then a little more vinegar. It is better to cook this product over low heat so that the starch swells evenly.

One explanation for why boiled potatoes turn black may be that they are “old.” In this case, you can add a small amount of milk during cooking.

If the potatoes will not be cooked immediately after peeling, it is better to keep them in cold water with a drop of vinegar added. It should be salted at the beginning of cooking, this will preserve more vitamins and beneficial components.

Where to keep peeled potatoes?

We have already figured out why potatoes turn black after peeling. This is due to the fact that the compounds contained in the product interact with air, and this, in turn, causes the oxidation process. This can be avoided by soaking the root vegetables in water and vinegar.

Every housewife has potatoes on her table. This is perhaps one of the most important root vegetables for preparing a variety of dishes. And indeed it is. Potatoes are added to most soups. And what a delicious puree you can make if you boil the vegetable correctly!

It is used not only in the daily menu, but also in the holiday menu. But sometimes it happens that after cooking the potatoes turn black. The appetizing appearance is immediately lost, and fears arise that such a root vegetable is harmful to the body. Many housewives have a question: “Why did it turn black?” We will look at where the stains come from and how to deal with this problem in more detail in this article.

Reasons for blackening of boiled potatoes

It turns out that not only raw potatoes darken, but also boiled ones. A raw vegetable turns black after cutting, because the tubers contain special components that, when in contact with air, give such a reaction.

After cooking, it also happens that the potatoes turn black. Don’t be scared and throw away the vegetable: consuming such a product is not at all dangerous or harmful. The only negative is the aesthetic appearance, which becomes unsightly, and the taste deteriorates slightly.

Reasons that lead to a vegetable turning black or blue:

• The soil where this root crop was grown was not sufficiently enriched with potassium or was fertilized with a mixture containing chlorine. This is unacceptable, because a large amount of acid negatively affects the taste and color of the fruit. In summer, a lack of potassium can be easily noticed by the appearance of the plant. In this case, the upper leaves turn yellow and curl, and eventually the stem. To avoid this, it is important to grow the vegetable correctly.
• Potatoes turn black after frosty days. Therefore, the plant should not be allowed to cool down.
• The excavation and transportation process must be careful. In places where tubers are damaged, blackness appears.
• It is very important to store vegetables correctly. The room should be well ventilated, and the potatoes should be well dried before being sent to the basement.
• During storage, you also need to monitor the temperature in the room. With high humidity there is a risk of mold formation. This needs to be monitored periodically; if wet tubers are detected, they should be dried well.

There are also certain varieties that contain a lot of starch. If you come across this variety, then the question of why the potatoes turn black after cooking disappears by itself. You just need to grow a different variety, and there will be no problem. It should be remembered that you should not eat green root vegetables: this is not only not healthy, but also dangerous to health.

How to prevent darkening of tubers?

Not every person has a summer house or a garden where they can grow their favorite vegetables. Most of us buy all our products in supermarkets and markets. And there you can’t always be sure of the quality of the product. Therefore, to prevent the potatoes from turning black after cooking, it is better to prevent this unpleasant phenomenon.

How to prevent vegetables from browning:

• When planting yourself, you should remember about the correct fertilizer. There should be no chlorine impurities, but potassium sulfate will be beneficial.
• Prevent tubers from being exposed to low temperatures. And when buying, you need to choose a quality product, there should be no cracks or blackening.
• Make sure that moisture does not get on the root crop before storing. Ventilate the room and dry the tubers sufficiently.
• If there are rotten or moldy potatoes, they should be thrown away. Then other tubers will not be infected.
• During the cooking process, you need to completely cover the potatoes with water.
• After cleaning, raw tubers must be stored in cold water before boiling.
• Good cleansing is also important. If the tubers are very dirty, it is better to wash them. There may be fertilizer in the dirt.
• To reduce the level of starch in root vegetables, you can leave them in cold water for an hour. After which it is recommended to pour out the liquid and pour in fresh liquid for cooking.
• One effective way is to use bay leaves. Add a couple of leaves to the water and the tubers will not change color.
• The acid helps prevent blackening. Vinegar or ascorbic acid are suitable for these purposes.

If you want to prevent your potatoes from turning black after boiling, you can use these simple tips. You should try to choose good quality vegetables. After all, both the taste of food and the benefits to the body directly depend on this.

Potatoes can rightfully be called the second bread. It contains many useful components and vitamins. Dishes made from root vegetables are satisfying and tasty. To make them look appetizing and aesthetically pleasing, try to avoid the appearance of dark spots.

The pulp of potato tubers may turn gray, black or bluish during cooking. Why does this happen and how to avoid it?

In such tubers, chlorogenic acid accumulates, which forms a strong complex with iron ions during cooking. As a result, the taste and culinary qualities of the tubers decrease and they change color.

There are several reasons for the darkening of potato tubers.

1. First of all - insufficient potassium intake. Potassium starvation can be determined during the growing season of plants. The leaves become dark green with a bronze tint. Then they turn yellow and brown, the tissue along the edges of the leaves dies. The internodes are shortened, the leaf segments are more closely spaced, and due to uneven growth, leaf wrinkling increases. First, these signs appear on the lower leaves of the bush, and then throughout the bush. To prevent this, it is necessary to add 1 square meter to the soil. m at least 30 g of potassium fertilizers (based on active substance).

2. The tubers turn blue and with an incorrect ratio of batteries. It is known that potatoes consume more potassium, slightly less nitrogen and even less phosphorus. Depending on the soil-climatic zone, the ratio of nitrogen, phosphorus, potassium when applying mineral fertilizers should be 1:1.5-2:1.5-2.2. Only on peat bogs is the dose of nitrogen increased. It is not recommended to use potash fertilizers containing sodium and chlorine.

Applying chlorine-free potassium fertilizers to potatoes promotes the accumulation of more citric acid in the tubers, which forms a colorless compound with iron.

3. The reasons for the darkening of potatoes may be injury to tubers during harvesting, loading and transportation, and bulkheading. When tissue is damaged, oxidative processes intensify, in particular, irreversible oxidative transformations of phenolic compounds occur.

4. Insufficient oxygen supply to the soil during the growing season, and especially during the formation of tubers, can also lead to their darkening. Violations of air temperature and humidity during storage of tubers, lack of oxygen and excess carbon dioxide also affect the quality of products.

Varieties are of great importance. In some early-ripening varieties, the tubers begin to darken during cooking already in April, especially at elevated storage temperatures.

So, in order to prevent darkening of the tubers when cooking potatoes, it is necessary to provide the plants with potassium, provide good soil aeration, and avoid injury to the tubers during harvesting and transporting the crop. It is also necessary to observe the optimal storage conditions for potatoes (temperature no more than 7-7.5˚C). Adding 1-2 bay leaves to the water reduces the darkening of tubers during cooking; the taste of the potatoes does not deteriorate.

Why potatoes turn black inside during storage - there are many reasons for this, from the choice of variety to the conditions of its storage in the cellar. Experienced gardeners, having learned from their mistakes, follow all the necessary rules. If the necessary storage conditions are created, potatoes can last almost until the next harvest.

Why do potatoes turn black inside?

Potatoes are a very popular vegetable in Russia; almost every gardener grows them. But it is important not only to get a large harvest, but also to preserve it. The most common problem in this case is that the tubers turn black inside. Sometimes even normal-looking vegetables have dark spots in their cut.

Important! Medium-sized mature tubers last the longest.

It is necessary to promptly identify the reason why the tubers begin to turn black inside during storage and eliminate it, otherwise the entire crop may be destroyed. Such signs can be caused by both the physiological disease melanosis, or gray spotting, and various infectious diseases caused by fungi.

Adverse weather conditions

Potatoes grow well in moderate humidity and temperature. If these indicators change, this negatively affects the yield and keeping quality of tubers:

• at high temperatures the vegetable overheats;
• at low temperatures, potatoes grow small due to lack of nutrients;
• if there is a lack of watering, the crop dries out;
• If there is an excess of moisture, oxygen does not reach the tubers well, provoking the development of bacterial and fungal infections.

All these conditions, individually or in combination, can lead to the vegetable starting to turn black inside. Thus, the product loses its consumer qualities.

Incorrect application of fertilizers

Some gardeners, in pursuit of large yields, fertilize their vegetable crops with too much organic matter. Herbal infusions, manure or green manure are used. These fertilizers promote plant growth due to their high nitrogen content. But during storage, such overfed tubers begin to turn black inside.

To avoid spoilage of potatoes after harvesting, you need to fertilize them according to the rules:

• Fresh organic fertilizers are not used, only rotted ones;
• manure is applied rarely - once every 2 years.

There is often an excess of nitrogen and a lack of potassium fertilizers in the soil. Namely, potassium is what contributes to the long-term storage of potatoes. Without it, it may begin to turn black.

Mechanical damage to tubers

Potatoes can also turn black inside due to mechanical damage that occurs during harvesting or transportation. Deformed parts of the potato subsequently change color. And if the skin is damaged, then there is a high risk of fungi and bacteria entering the vegetable.

Potatoes turn black inside during storage also when they are placed in several layers. The tubers lying below experience quite a lot of pressure.

Infectious diseases

The appearance of characteristic dark spots inside tubers is usually accompanied by diseases such as:

• Blackleg. A disease called blackleg affects potato tops and tubers. Its first symptoms appear during crop storage. It is rot that reaches inside the center of the tubers, and they begin to turn black. Externally it can be distinguished from gray spotting. The entire fruit is affected, beginning to emit an unpleasant odor. Potatoes lying nearby are also susceptible to infection. It is important to identify the disease at the growing stage in order to prevent such vegetables from entering storage.

• Late blight. The disease is common in almost any climate where potatoes are grown. Both tops and tubers are affected. The fungus spreads quickly, harming all plants. Brown spots appear on the leaves, they rot and dry out. The disease is transmitted through weeds and progresses when agricultural practices for potato cultivation are violated. Tubers affected by late blight become covered with brown spots on the inside. High temperature promotes the development of fungus. Potatoes become infected during harvest or from their own diseased tops. The likelihood of transmission from a neighboring tuber during storage is minimal. Late blight can also provoke diseases by other fungi.

Improper storage

The potato harvest is stored in a basement at a temperature of +1 to +4 °C. If the indicator drops below, the tubers become sweet and begin to turn black inside. At higher temperatures, potatoes germinate and the risk of gray rot increases.

Late cleaning

Timely harvesting of potatoes is the key to preserving the resulting harvest. To prevent the tubers from starting to turn black inside, adhere to the following rules:

1. When harvesting potatoes, you must be guided by varietal characteristics - a crop harvested too early will most likely turn black inside during storage. Tubers must ripen in natural conditions.
2. Harvesting must be done before the first frost. If you leave potatoes in the ground at a temperature of -1 ° C, they will freeze and then rot during storage.
3. After the tops have been mowed, the tubers must be collected as soon as possible. If warm weather begins, the vegetable may overheat.
4. The collected potatoes are stored in a dry, well-ventilated room at a temperature within +4 °C.

Harvesting potatoes in a timely manner reduces the likelihood that the tubers will begin to turn black inside during storage.

What to do to prevent potatoes from turning black

Very often situations arise when potatoes lay in the basement all winter, and by spring they began to turn black. This could be due to poor ventilation.

As the weather gets warmer, the potatoes move into storage and sprout. The pulp darkens and becomes limp. There is a sharp jump in temperature, moisture is released, and the debate continues. Thus, you can lose the entire harvest.

To prevent potatoes from starting to turn black inside during storage, you must follow a number of rules:

• After harvesting, potatoes should be placed in the fresh air for 20 days;
• place it in wooden boxes equipped with ventilation holes;
• maintain the required temperature in the storage;
• boxes and pallets should be moved 20 cm away from the walls;
• potatoes are sorted at least once - sprouted and diseased tubers are removed, as well as healthy ones located next to them;
• if storage is carried out at home on the balcony, then it is recommended to cover the boxes with a warm blanket;
• Potatoes can only be stored together with beets, which will take away excess moisture from them; proximity to other vegetables is strictly prohibited.

Is it possible to eat darkened potatoes?

If the potato has turned black inside due to rot or infectious diseases, then it should not be eaten. In other cases, eating such tubers is allowed, but they lose their beneficial properties and taste. They are low in vitamins, protein and starch. Dishes made from such potatoes look unattractive, so tubers with black spots are not eaten.

Storage rules

How long the potatoes will last depends on proper preparation for storage and the conditions in the cellar itself. The choice of variety when planting also influences. The main factors that must be taken into account for the safety of the crop:

1. When planting, you need to think about which varieties you will need, because they are stored differently. Late potatoes are intended for long-term storage in the cellar. Even under ideal conditions, early varieties will not last long. They are intended to be eaten directly during the season.
2. Before being sent for storage, the tubers are sorted and sorted - diseased, damaged, and suspicious ones are removed. Potatoes that come into contact with diseased vegetables should also be removed; they may be infected, but symptoms have not yet appeared. Even a few diseased tubers can destroy the entire crop in storage. Potatoes must be dried, otherwise raw tubers may turn black inside and rot.
3. Constant monitoring of the temperature in the place where the crop is stored is necessary. Special control is needed during the changing seasons in autumn and winter, when there is a risk of temperature fluctuations.

Important! Some potato varieties contain a lot of starch and a slight browning is normal for them.

To maintain the desired air temperature in the storage room, use ventilation and bottles of cold or hot water placed around the perimeter of the cellar. This reduces the risk that the vegetable will begin to turn black inside. With timely control of humidity and temperature, potatoes can be preserved.

Conclusion

There are many reasons why potatoes turn black inside during storage. If you choose the right variety, follow the watering and fertilizing regime, then such a problem can be avoided. It is also worth harvesting, guided by the rules available for this. The final and one of the main points in the preservation of tubers is the conditions of their maintenance in the cellar.