Decomposition temperature of vitamins. How many vitamins are lost after cooking - why can't we understand Indonesian gourmets? Ascorbic acid is an important factor in health and wellness

We became friends with this vitamin in early childhood. Who didn't ask mommy to buy sour pills when she went to the pharmacy? Askorbinka was given to us with a cold, when there was no currant jam in the house. We learned that vitamin C and ascorbic acid are the same substance when we ourselves became fathers and mothers. Unfortunately, the information received about this most important "element of life" for many is still scarce and scattered.

Meanwhile, vitamin C deserves to know as much as possible about it. Its importance for health cannot be overestimated. I will tell you about the medicinal properties of ascorbic acid, about food products and plants in which it is contained.Let's talk about what problems arise with its lack and how much of this substance a person needs for normal well-being.

Another important topic that should be touched upon is the misconceptions and myths associated with the destruction of vitamin C during the heat treatment of food and the brewing of medicinal herbs.

After reading this article, you will discover the powerful healing properties of ascorbic acid and its great importance for the prevention of diseases.

The history of the discovery of vitamin C

Few people know that vitamin C was discovered not in the laboratory, but during sea voyages. The Englishman James Lind, a naval surgeon by profession, proved that the presence of oranges and lemons in the diet of sailors saves them from scurvy. It happened back in 1747.

Later, his discovery was enshrined in the scientific name of vitamin C. The word "ascorbic acid" contains the Latin name for scurvy (scorbut). Particle A means negation. It turns out that the substance found in the fruits of citrus plants prevents this terrible disease that has tormented sailors and polar explorers for centuries.

Two centuries passed and Lind's work was continued by the Americans. They managed to isolate ascorbic acid from fruits and proved that this is a new substance. The significance of the discovery was so great that the head of the team of scientists, Albert Szent-Györgyi, won the Nobel Prize in 1934. At the same time, a method was found for the chemical synthesis of “ascorbic acid” and the first preparations containing it appeared.

The joy of the researchers was overshadowed by the fact that ascorbic acid in its chemically pure form did not save from scurvy. Only its extracts obtained from vegetables and fruits had a therapeutic effect. Let's take this fact into account when we talk about the biological formula and properties of vitamin C.

Vitamin C - it's not as simple as it seems

The structure of natural vitamin C is much more complicated than the formulas of its synthesized analogues sold in pharmacies. Accordingly, the effectiveness of the natural substance is much higher.

Vitamin C contained in vegetables, fruits and berries consists of two types (isomers) of ascorbic acid. It also contains the substance ascorbigen, which has anti-cancer properties, and eryterbic acid, a powerful antioxidant.

The healing power of natural ascorbic acid increases many times due to enzymes, bioflavonoids and rutin, which are not found in synthetic vitamins. It is for this reason that the crystalline powder of "ascorbic acid" is not able to cure a person from scurvy.

Vitamin C Properties

It should be remembered that vitamin C is classified as essential. Our body does not know how to produce it, but cannot live without it. Another problem is that the vitamin in question does not accumulate in organs and tissues. That is, we cannot hope for its “strategic reserve”. It is not difficult to draw a conclusion from what has been said: vitamin C must be constantly present in our diet.

The main task that it performs in the body is to strengthen the immune system. This natural barrier resists the invasion of harmful microbes and protects us from the negative effects of the environment.

No less valuable is the ability of vitamin C to fight allergens and reduce stress.

The natural complex of ascorbic acid strengthens blood vessels, accelerates wound healing and is involved in the utilization of harmful cholesterol, which provokes cardiovascular diseases.

Without vitamin C, the body cannot produce adrenaline and folic acid, the "female vitamin" B9. For those suffering from diabetes, it brings relief by lowering glucose levels. Its beneficial effect on the eyes protects the elderly from glaucoma and cataracts.

Vitamin C activates the endocrine system, stimulates the liver and neutralizes toxins that poison the body. By protecting antioxidant vitamins E and A from oxidation, it increases their working time for the benefit of our health.

Without it, there is no process of formation of connective tissue and collagen necessary for skin renewal, strength of tendons, blood vessels, teeth and bone tissue.

One of the reasons for low hemoglobin is a lack of vitamin C. It is necessary for hematopoiesis, since it is directly involved in the synthesis of hemoglobin.

Scientists have found that vitamin C supports more than 300 life processes in the human body! This fact eloquently testifies to its exceptional importance for our health.

What does vitamin C deficiency lead to?

Scurvy, one of the most devastating diseases caused by a lack of vitamin C, does not threaten us today. But there are plenty of other problems caused by its deficiency, and they are all very serious:

• ● nosebleeds and bleeding gums;
• ● bruising with minimal physical impact;
• ● fragility of the eye blood vessels;
• ● poor wound healing;
• ● frequent colds;
• ● general weakness, apathy;
• ● joint pain;
• ● dry skin, hair loss and swelling of the face;
• ● anemia (anemia);
• ● irritability.

How much vitamin C does the body need

The physiological norm of a healthy person is 70 mg per day. In the conditions of modern life, with its sick ecology, food chemistry and stress, the body needs much more ascorbic acid. Any disease dramatically increases the deficiency of vitamin C, which is used by the immune system to fight the threat. Therefore, for colds, flu and other infectious diseases, doctors prescribe to patients shock doses of "ascorbic acid" - from 500 to 2000 mg per day.

During pregnancy and while breastfeeding, the norm of vitamin C increases to 150 mg. Intensive sports require its intake in a dosage of 250 to 500 mg. Heavy smokers, like athletes, need vitamin C. To neutralize toxic nicotine, it must be introduced into the diet in an amount of at least 200 mg.

Those who work under stress, work in the Far North or the hot South, should increase their intake of vitamin C by 2-3 times compared to the physiological norm.

In old age, the need for this substance also exceeds the medically recommended 70 mg per day, reaching a level of 100 mg.

Aggressive pharmaceutical chemistry, without which the treatment of most diseases is indispensable today, gives a lot of side effects. To smooth them out, we also need a natural “ascorbic acid” in a double dosage (140 mg / day).

Where is vitamin C found

The main suppliers of this essential vitamin are plants. Most natural ascorbic acid is found in rose hips: 650 mg / 100 g in fresh fruits and in dry berries of this plant, the concentration of "ascorbic acid" reaches 2000 mg.

In second place are three representatives of the plant world at once: blackcurrant, sea buckthorn and sweet bell pepper (200 mg / 100 g). With a slight lag, they are followed by the fruits of the exotic kiwi fruit - 180 mg. Immediately after them, we will put parsley and porcini mushrooms (150 mg).

Fifth place in the ranking is occupied by dill, broccoli and Brussels sprouts - 100 mg. Orange, presented to us as a powerful source of vitamin C, takes a very modest sixth place (60 mg), sharing it with strawberries, red rowan, papaya and pamelo fruits.

From animal products, ascorbic acid is found only in the liver (chicken, lamb, beef and pork). Here its concentration is from 20 to 40 mg/100 g. It is not found in meat delicacies.

Cooking, freezing and vitamin C - myths and reality

The expanses of the Internet are roaming "horror stories" that are firmly planted in the minds of many people. They talk about the almost complete destruction of vitamin C as a result of heat treatment and freezing. Let's look at this issue objectively, based on experimental data.

The Siberian Academy of Sciences on March 7, 2013, within the framework of the 8th International Scientific and Practical Conference, published the results of specialized research. Their subject was the study of the dependence of vitamin C content on heat treatment and freezing of fresh fruits (Table No. 1).

The table shows that even after 5 minutes of boiling, the loss of vitamin C does not exceed 58%. Based on this, the following conclusion can be drawn: when brewing herbs and short-term heat treatment of fruits, ascorbic acid is stored in an amount sufficient to make up for its deficiency.

Freezing has an even lesser effect on the amount of ascorbic acid. The table shows that its losses in this case do not exceed 33%.

Lovers of jam and other sweet homemade preparations may not worry. Vitamin C is preserved in sufficient quantities in these delicacies. The acidic environment protects it from destruction. Organic acids (malic, citric, oxalic and others) are always present in fruits and vegetables. When cooking jam, compote, jelly, mousse and other sweets, an acidic environment is created in which vitamin C feels great.

Only a combination of two factors has a detrimental effect on ascorbic acid: long-term heat treatment (more than 30 minutes) and its high temperature (+100C).

Without detracting from the highest vitamin qualities of fresh berries and vegetables, you should not refuse and put an end to thermally processed foods. Considering that freshly picked seasonal fruits, berries, herbs and vegetables occupy a smaller share of the diet than frozen and thermally processed ones, we get no less vitamin C from the latter.

Also, do not worry about brewing herbs and berries (in particular, rose hips) with boiling water. When brewing herbal teas with boiling water, the destruction of vitamin C occurs within the specified normal limits, but we ensure the disinfection of herbs taken from nature.

Changes in vitamins in fruits and vegetables

Carotenoids are stable and their amount practically remains unchanged during heat treatment. There are very few vitamins of group B in plant products, and during hydrothermal treatment they turn into a decoction and are destroyed slightly.
Vitamin PP is not destroyed by boiling, exposure to oxidizing agents and light. It is one of the most stable vitamins.
For an animal organism, three substances are equivalent in biological action: pyridoxine, pyridoxal and pyridoxamine. All three compounds with the biological activity of vitamin B6 are resistant to heat, unstable to the action of oxidizing agents, such as peroxides, as well as swat.
Pantothenic acid is resistant to atmospheric oxygen at room temperature, it is destroyed by autoclaving and heating in acidic to alkaline solutions.
Biotin is resistant to heat and dilute acids and alkalis. Prolonged aeration and H2O2 do not affect its activity.
Choline is a colorless, alkaline, syrupy substance that is resistant to heat.
The greatest degree of destruction is observed in vitamin B6: when cooking spinach, it decreases by 40%; white cabbage by 36%; carrots by 22%.
Vitamin B12, when heated in aqueous solutions, is most stable at pH 7, at pH 2 there is a slow loss of activity, and at pH 9 - rapid destruction. Autoclaving of this vitamin at 121°C in a neutral medium for 15 minutes does not change its activity. It is destroyed in solutions under the action of light.
Vitamin A and carotene are highly reactive due to the presence of a large number of double bonds. They are unstable to heat in the presence of oxygen, but stable in its absence. Vitamin A in the absence of oxygen can be heated to 120-130 ° C without changing the chemical structure and loss of biological activity, it is destroyed by ultraviolet rays.
Vitamin D is resistant to high temperatures, as well as to oxygen, but when heated no higher than 100 ° C.
Tocopherols are resistant to heating up to 200°C in the presence of oxygen; destroyed by ultraviolet rays and some oxidizing agents.
Vitamin K is resistant to high temperatures, except for heating in an alkaline environment. Destroyed by ultraviolet rays.
Vitamin C undergoes significant changes. Ascorbic acid is oxidized by atmospheric oxygen under the action of an enzyme, it passes into dehydroascorbic acid. Upon further heating, both forms are destroyed. The rate of destruction of ascorbic acid depends on the properties of the processed semi-finished product, heating rate, duration of treatment, contact with atmospheric oxygen, composition and pH of the medium. The higher the content of vitamin C and less dehydroascorbic acid, the less it is destroyed. The faster the heating, the better the preservation of vitamin C, the faster the enzyme that oxidizes vitamin C is inactivated. The presence of oxygen, copper, iron, manganese in the cooking medium reduces the amount of vitamin C.
Vitamin C is less destroyed in an acidic environment. When vegetables are cooked in an acidic environment (tomato paste), vitamin C is better preserved (due to the weakening of the action of copper ions).
Ions of copper, iron, magnesium, contained in tap water or entering the cooking medium from the walls of dishes, catalyze the destruction of vitamin C.
Substances contained in vegetables and fruits (amino acids, vitamin A, E, thiamine, anthocyanins, carotenoids) prevent the destruction of vitamin C. Cooking in broth preserves vitamin C.
Storing food in a hot state, vitamin C is destroyed at room temperature. The greatest loss of vitamin C is during poaching. During frying, it is destroyed less than during hydrothermal treatment, since there is less oxygen access, rapid heating, and a short period of thermal exposure. In the manufacture of products from vegetable cutlet mass, up to 90% of vitamin C is destroyed.
Cutting vegetables and fruits leads to an increase in the destruction of vitamin C.

MOSCOW, October 14 - RIA Novosti, Olga Kolentsova. The role of proteins, fats and carbohydrates in the body is clear - they are sources of energy and building material. But it's hard to build a house without the right tools, which is what vitamins are. They are responsible for the normalization of almost all processes in the body, their deficiency leads to disruption of the functioning of our body, which can cause serious illness. The most famous example is scurvy, a disease caused by a lack of vitamin C.

There are 13 vitamins in total: A, C, D, E, K, H, B1, B2, B3, B5, B6, B9, B12. They are divided into two groups: fat-soluble (lipophilic) and water-soluble (hydrophilic). The first group includes A, D, E, K, and the second - all the others.

To use the required dose of vitamins, it is not enough to know the proportion of their content in products. The fact is that food processing and even your own bad habits (smoking and addiction to alcohol) can destroy beneficial substances. To get the required amount of vitamins, you need to know why exactly the products can lose their beneficial properties.

Vitamin C is called ascorbic acid (chemical formula C6H8O6) and is recommended for boosting immunity. But this connection is extremely fragile: light, temperature, and contact with air can break the bonds in it.

© RIA Novosti illustration. Alina Polyanina

© RIA Novosti illustration. Alina Polyanina

Of course, if you put a slice of lemon in hot tea, vitamin C will not be completely destroyed, since the ascorbic acid molecule decomposes at a temperature of 190 ° C. But it must be understood that the decrease in the amount of vitamin in the product is not directly proportional to the processing temperature.

100 grams of lemon contains 40 milligrams of vitamin C. According to studies, after treating a lemon with boiling water for five minutes, it retains 1.31 milligrams of vitamin per 100 grams of product, and when infused in water at room temperature - 0.704 milligrams. The fact is that at a temperature of 50 ° C, oxygen still remains in the products. This element has a high electronegativity, that is, the ability to pull the electron of another atom onto itself, due to which its former connection is destroyed. And at a temperature above room temperature, the oxidation reaction begins to proceed more actively, "tearing off" atoms from ascorbic acid. But when the water contained in the product boils, oxygen evaporates, therefore, the number of oxidative processes decreases.

But, for example, iron or copper can also participate in the oxidative reaction, so you should pay attention to the choice of dishes and appliances for preparing foods rich in vitamin C.

Light also breaks the bonds in the ascorbic acid molecule, so chopped vegetables retain the maximum amount of the vitamin in a dark refrigerator. The peel, on the other hand, protects products not only from exposure to light: for example, in a potato baked with the peel, the vitamin content will be higher than in its "naked" counterpart.

© Photo: Dmitry Ukhov and Alexander Kolpakov

© Photo: Dmitry Ukhov and Alexander Kolpakov

The equally well-known vitamin A, or retinol (chemical formula C20H30O), is essential for vision, bone growth, healthy skin and hair, and the normal functioning of the immune system.

It withstands high temperatures (up to 120-130°C) in the absence of oxygen. However, vitamin A is completely resistant to room temperature water. But open air destroys it, as does light containing ultraviolet rays. Their energy is enough to break the chemical bonds in the compound. In addition, this element also does not combine with alcohol, so the liver in wine will not be the best option for those who want to cook a dish rich in vitamin A.

© RIA Novosti illustration. Alina polyanina

© RIA Novosti illustration. Alina polyanina

The group of B vitamins includes five different substances: B1, B2, B3, B6, B12. B1 is destroyed when exposed to high temperature (120°C), but can withstand up to 140°C in an acidic environment. When you add baking soda to baking, you destroy vitamin B1, as it does not tolerate the neutral and alkaline environment that soda creates. He is also afraid of low temperatures - when frozen, half of the vitamin B1 contained in the product is lost. Salt also harms him, so you should add it to foods rich in B1 immediately before eating.

Its closest "brother" riboflavin (B2) is destroyed by approximately the same factors, but is slightly more resistant to heat. B3 is one of the strongest in this group and is destroyed only under the influence of alcohol. B6 (pyridoxine) is unstable to sunlight, but resists oxidation and heat treatment. Cobalamin (B12) is afraid of water, alcohol and sunlight, and is also destroyed by contact with copper and iron. But not afraid of high temperatures!

All B vitamins are soluble in water. That is why buckwheat, rich in this element, should be boiled so that it completely absorbs water.

Many people think that raw foods are the healthiest. In most cases, this is true, but sometimes a simple hit on such products in direct sunlight can devalue them as a source of vitamins. And treatment with hot water (for example, 50°C) does not always preserve vitamins better than immersing them in boiling water (100°C). Therefore, if you want to enrich your body with useful substances, you should carefully study their properties and resistance to heat treatment.

I looked at culinary sites in one of them I became interested in the “Healthy Eating” section. So many recipes! But I was embarrassed that, for example, cabbage cutlets are served as a recipe for a healthy diet and a high content of vitamins!

Description: These cutlets are just a lifesaver for me. Quick, easy, helpful! Nothing is fried, but baked. My kids just love them, especially with sour cream!

Butter - 2 tbsp. l.

Egg - 2 pcs

Milk - 100 ml

Oat flakes - 3 tbsp. l.

White cabbage - 400 g

Finely chop the cabbage. Simmer with the addition of oil and water for about 15 minutes. Add hercules, salt. Add milk and simmer for another 10 minutes. Let's cool down! Add eggs, mix. Put into molds. Bake in an oven preheated to 200 degrees for about 30 minutes. Serve with sour cream! From this amount of products, 6 cutlets are obtained.

The benefits of this dish are obvious! Here, nothing is fried in oil, but baked, which is very beneficial for the body. In addition, cabbage is a good source of ascorbic acid. For 100g. cabbage leaves can have up to 50 mg of vitamin C. Over time, its supply decreases. So, after 3 months of storing a vegetable in the cellar, the amount of ascorbic acid decreases by a quarter, and after six months by more than a third. Sauerkraut, on the other hand, is even richer in vitamin C than fresh cabbage, and the content of vitamin P is increased by as much as 20 times. In addition to ascorbic acid, cabbage contains vitamins K, U, B and many trace elements: potassium, calcium, phosphorus, sulfur. Vitamin U is known as the "anti-ulcer" vitamin. Potassium supports the normal functioning of the heart muscles, prevents the formation of blood clots, and lowers cholesterol. Calcium and phosphorus strengthen bones, teeth, nails and hair. Since ancient times, cabbage has been considered a medicinal plant. In ancient Greece, she was treated for diseases of the lungs and liver, ulcers. Fresh cabbage juice was used to treat gastritis, gastric and duodenal ulcers. The benefit of cabbage is that it contains few carbohydrates, so it is used in diabetes. HERCULES. Hercules is one of the leaders among other types of cereals in the content of nutrients (phosphorus, iodine, silicon, potassium, calcium, zinc) and vitamins (B, C, A, E, PP). The name Hercules passed to porridge from the ancient Greek hero of the same name, also known by his second name - Hercules. And not by chance. The richness of hercules in amino acids and complex carbohydrates gives our body an extraordinary strength inherent in the hero of mythology. Hercules is useful to use to avoid stressful situations. Large doses of vitamin C help keep the body's immune system in good condition, and B vitamins contribute to the excellent functioning of the nervous system.

And this is where I got a little carried away! Double heat treatment of cabbage, oatmeal! Plus milk! Plus heat treatment of butter! And what is the benefit, besides fiber and the remaining trace elements, preserved in this dish? Where is the healthy food?

Naturally, Yandex to help me, I began to look for an excuse for my own indignation. And here's what I found:

Vitamin A withstands very high temperatures for a fairly short time.

Whereas vitamin E is almost not destroyed by exposure to high temperatures.

It is destroyed by about 30% with short exposure to high temperatures, but when boiled, it is completely destroyed.

Vitamin B2 destroys during heat treatment by 15 percent, and is completely destroyed in sunlight.

Vitamin B3 responds normally to heat treatment.

Vitamin B5 during heat treatment is destroyed by about 50 percent.

Vitamin B6 responds normally to heat treatment.

Vitamin B9 is very sensitive to heat treatment.

Vitamin B12 is destroyed after about a few hours during the boiling process.

Vitamin C is rapidly destroyed by heat treatment.

Vitamin D responds normally to heat treatment.

Vitamin K is very sensitive to heat treatment.

And I came to the conclusion: In order for food to be healthy, it must be a raw food diet!!!

Let's start with a disclaimer: it is difficult to predict exactly how heat treatment will affect vitamins. There are too many factors at play: it all depends on the temperature during cooking, how the vegetables were grown, whether they were frozen, fresh, pre-cut or cooked whole, and so on.

Another important point: research is carried out on a rather limited set of products. The most popular experimental vegetables are carrots, broccoli, and. And the results of experiments often turn out to be different even with identical preparation methods. And how the same vitamins will behave in other foods, one can only guess.

And the experiments themselves, frankly, are not similar to the actions of an ordinary person in the kitchen. For example, in one study, cooked vegetables were cooled to minus 80°C before measuring the micronutrient content.

We studied all the studies and chose the most intelligible.

What happens to vitamins during cooking

Vitamin C

Contained in broccoli, spinach, watercress, red pepper, zucchini, carrots, potatoes, kiwi, currants, citrus fruits, papaya, strawberries.

What kind of cooking hurts. Generally not helpful boiling or frying. But there are nuances. Study , which used broccoli, spinach and lettuce, showed that when cooked, the content of vitamin C in these products is reduced by 40-54.6%. Wherein it does not affect carrots and zucchini so badly: the amount of ascorbic acid declining only by 9 and 15%, respectively.

How best to cook.For a couple: in this way, the losses will be only 8-14%. A gentle alternative blanching , which, for example, is great for broccoli.

Vitamin A

Found in sweet potatoes, beef liver, spinach, orange and red vegetables, zucchini, broccoli, dairy products, eggs, dried apricots, mangoes.

What kind of cooking hurts. In experiment with carrots, zucchini and broccoli, frying not only reduced vitamin A by 67%, but also reduced the amount of other antioxidants in vegetables.

How best to cook.Cook. In the case of vitamin A, this is the most gentle way. Moreover, the content of antioxidant carotenoids, precursors of vitamin A, increases in cooked vegetables (for example, in carrots by 14%).

But there is a catch: in zucchini, other useful substances, polyphenols, are destroyed during cooking. Therefore, it is better to cook them in pairs.

Vitamin E

Contained in nuts, seeds, buckwheat, sprouted seeds, peppers, broccoli, spinach, chard, zucchini, papaya.

What kind of cooking hurts.There are no exact data.

How best to cook.Boil, steam or microwave for 5 minutes. All three ways increase the amount and bioavailability of vitamin E in green plants such as broccoli, chard and spinach. Zucchini also falls into this group, but its cooking time can be increased to 10-12 minutes.

Alas, these same methods will reduce the concentration of the trace element in potatoes, sweet potatoes and carrots.

Vitamin K

Contained in cabbage, green tomatoes, spinach, rowan berries, liver, pumpkin, carrots, potatoes, legumes, egg yolk, beets.

What kind of cooking hurts.There are no exact data.

How best to cook.It is known that vitamin loss will be small if spinach and chard are cooked in the microwave. Scientists suggest that heat treatment leads to an increase in the bioavailability of the vitamin, but further studies are needed to confirm this hypothesis.

Vitamin D

Contained in fatty fish, seafood, liver, eggs, mushrooms, whole grain bread and specially fortified foods - milk, yogurt, breakfast cereals.

What kind of cooking hurts.There are no exact data.

How best to cook.Vitamin D enough stable to heat treatment, but the optimal method of preparation depends on the product.

For example, if eggs are boiled, they retain up to 84% of the vitamin, and ifbake in the oven – maximum 45%. For fish fit baking at a temperature of 172-200 ° C for 20 minutes, in this case, the loss of vitamin D will not exceed 10%.

Vitamin B 9 (folic acid)

Contained in beef and beef liver, spinach, beans, asparagus, Brussels sprouts, broccoli, green peas, avocados, rice, potatoes, bananas, and specially fortified foods such as bread and pasta.

What kind of cooking hurts. Cooking is known to reduce 51-56% folic acid content in spinach and broccoli. Much decreases the amount of B 9 in a potato if it is baked in the oven with the skin on.

How best to cook.Ideal for potatoes method sous vide (cooking in a special vacuum bag at low temperature). However, during normal cooking, potatoes (in their skins and peeled) lose a small amount of folic acid.

Legumes can be boiled for no more than 2 hours, cooked in the microwave or steamed. All three methods will save up to 77% of the vitamin, and at the same time reduce the concentration of phytic. Spinach and broccoli are best steamed for 4.5 to 15 minutes. The grill can be used for beef.

Vitamin B12

Found in animal products: in beef and chicken liver, octopus, herring, mussels, mackerel, beef, lamb, turkey, egg yolk, dairy products.

What kind of cooking hurts.Little information. Known , for example, that fried beef loses about 32% of vitamin B 12 . And its content in fish, apparently, is reduced by 38% with almost any heat treatment. At least such results obtained by Japanese scientists when they boiled, fried, grilled, microwaved and steamed herring meat.

How best to cook.Beef - bake or grill: so the loss of vitamin will be negligible. The only method of heat treatment that does not affect the content of B 12 in fish is cooking in a vacuum bag (according to the same experiment with herring).