Friends, how to avoid nitrite in cooking

Nitrite is mainly broken down by bacteria.

Nitrite refers to the conversion of nitrite to nitrite due to the consumption of cured meat products, kimchi and spoiled vegetables with high nitrate content.

Pickles and kimchi can also produce nitrite, but the peak occurs on the seventh day of pickling, and if eaten half a month later, the nitrite in it will be greatly reduced.

The production of nitrite in vegetables, the raw material is nitrate in vegetables, and the transformation conditions are mainly bacterial growth.

Nitrate in vegetables is converted to nitrite. This transformation process can be achieved by the original reductase enzymes in the vegetable, but when the vegetable is heated and cooked, these enzymes lose their activity and this path is truncated. Another pathway is the action of bacteria.

Originally, the vegetables were cooked, and the bacteria in them were almost killed. But in the process of eating, some bacteria on the chopsticks will enter the leftovers; During storage, some airborne bacteria may also enter. Cooked vegetables are more suitable for bacterial growth, and under the right conditions, they can grow in large quantities, and nitrates can be converted to nitrite during the growth process.

Overnight meals are not called overnight, but the scientific time is (1 to 10 hours), and after 10 hours, the time is called overnight.

Water contains trace amounts of nitrate, and when the water is heated for a long time, the concentration of nitrate increases relatively due to the continuous evaporation of water, and it is decomposed into nitrite by heating. If it is stored for too long or improperly, bacteria can multiply, and nitrate can also be converted to nitrite.

Sodium nitrite is a food additive, which is used in the processing of meat products, and the maximum residue of nitrite in meat products is 30mg kg.

However, nitrite is not always artificially added, and nitrite is also widely found in natural foods. Don't ignore the presence of nitrates in food ingredients!

Nitrate and nitrite are widely found in natural soils and waters. Some plants also contain nitrates, and different varieties have different contents, such as sugar beets, lettuce, spinach, celery and radishes in green vegetables. This is due to the cultivation of crops and the use of nitrogen-containing pesticides and nitrogen-containing fertilizers.

In addition, some pickled vegetables have problems with the process, resulting in high nitrite content, and nitrite content has been reported to be as high as 78mg kg in some varieties. The Northeast region, which likes to eat sauerkraut, has a higher incidence of stomach cancer, which may be caused by long-term intake of nitrite.

1. Nitrite is a class of nitrogen-containing inorganic compounds that are ubiquitous in nature, which can be used as a food additive in meat products.

Nitrite and nitrate are nitrogenous inorganic compounds that are ubiquitous in nature. The nitrogen cycle in nature, as well as human activities, is an important part of nitrate. In the formation of nitrate, nitrite is often produced due to the action of microorganisms.

Common nitrites mainly include sodium nitrite and potassium nitrite, which are similar in appearance to table salt, white to light yellow, powdered or granular, odorless, slightly salty in taste, easy to deliquescent and soluble in water.

Nitrite appears in vegetables 5 to 15 days after salting, and will gradually decrease later, so it is safer to eat after 30 days of salting.

Study on nitrite content in pickled vegetables and measures to reduce it.

Overview: The nitrite content in pickled cabbage and mustard at different pickling stages was analyzed, and the effects of sodium VC and sodium benzoate on nitrite in pickled cabbage and mustard were analyzed, and the results showed that nitrite reached the highest peak after 20 days of pickling (when half-cooked), and then gradually decreased.

The antioxidant sodium isoVC has a certain effect on preventing the reduction of nitrate to nitrite, while sodium benzoate does not.

Expert: "The nitrite content has a clear peak of growth during the curing process, called the nitrosation peak. In general, pickled products have the highest nitrite content in 4 to 8 days, begin to decline after the 9th day, and begin to disappear after 20 days, at which time they can be eaten.

According to the relevant regulations of the state on the declaration of green food for pickled vegetables, the nitrite content in sauerkraut should be 4 mg per kilogram, that is, the weight of half a millet grain, if you eat 20-30 grains of millet, so much nitrite can cause poisoning, excessive intake of nitrite will cause hemoglobin in the blood to become methemoglobin, so that red blood cells lose their oxygenated function, resulting in tissue hypoxia, and bleeding lips, headache, dizziness, nausea and vomiting, palpitation and other poisoning symptoms, In severe cases, it can also lead to death. ”

Beware of nitrites when eating pickled vegetables.

At present, it is the season to eat pickled vegetables, crispy cucumbers, refreshing snow mushrooms, flavorful radish strips, spiced gnocchi, as well as Korean kimchi and Northeast sauerkraut? They are all excellent side dishes when drinking porridge.

But some people say that eating pickled vegetables can cause cancer, is it true?

In stale vegetables, nitrate can be converted to nitrite.

If nitrite enters the human blood circulation, it oxidizes the hemoglobin in the blood, which can weaken the ability of hemoglobin to carry oxygen, resulting in food poisoning caused by hypoxia. Nitrite turns into nitrosamines under the action of bacteria in the stomach, which has carcinogenic effects.

Pickles are not fresh vegetables, but kimchi is a strict lactic acid fermentation, and sauerkraut is also acetic acid fermentation, which can protect nutrients such as vitamin C under acidic conditions, and is not conducive to the formation of nitrite. Therefore, the nitrite content of kimchi and sauerkraut, which is not contaminated by miscellaneous bacteria, is very low. Nitrite appears in vegetables 5 to 15 days after salting, and it will gradually decrease later, so it is safer to eat it after 30 days of salting.

Adding some vitamin C to pickles can reduce nitrite production, and the blocking rate of nitrite by adding 400 mg of vitamin C per kilogram of pickles.

In short, as long as it is processed reasonably and eaten in a timely and appropriate amount, pickled vegetables will not become a carcinogenic factor. (Li Xiaoguang).

Teacher Wu: "I make sauerkraut, the first cabbage to choose is better, to be small, and the core should be full, and then wash the cabbage clean, I want to use cool white to pickle sauerkraut, my experience is to put a little C when pickling, a kilogram of cabbage can put 4 grains C, the role of vitamin C is mainly to block the generation of nitrite. Brother Tong".

The nitrite levels in food are a cause for concern. For example, the only remaining leafy greens. At the same time, it is also a common food additive.

It is generally used in meat products for its color, preservative, and flavor improvement. Vegetables, meat, seafood you have it. Maintain a balanced diet.

Vegetables and fruits are eaten in different ways. Avoid long-term support for a few foods. Eat less overnight dishes.

Because it is easy to be contaminated by bacteria. Vegetables should be eaten fresh. Fresh vegetables are very low in nitrite.

If stored for too long, nitrates from bacteria and vegetables are converted to nitrite.

Nitrite cannot be removed from food, only reduced or neutralized. A small amount of nitrite is harmless to the human body, and the human body will eliminate it through metabolism, so you don't have to pay too much attention to it, which will have a psychological burden. Sauerkraut, pickles, salted fish, bacon, bacon, etc., in the process of making these foods, the harmful substances to the human body - N-nitroso compounds will increase, and should be avoided as much as possible.

Boiling water, cooking food for too long can also accumulate nitrites. Nitroso compounds are relatively stable in an alkaline environment and are not easy to hydrolyze under general conditions, but they can be hydrolyzed when heated to 70 100 in an acidic environment, and can be cleaved under sunlight, but vitamin C, vitamin E, etc., can block the formation of N-nitroso compounds. Therefore, in daily life, we can also reduce its content in food through certain processing methods and reasonable food combinations.

1.Nitrate and nitrite are widely present in vegetables, and nitrate is the main in fresh vegetables, nitrite is much lower than nitrate, and the nitrite content in pickled and stale vegetables will increase significantly, and the increase can be several times to hundreds of times. Fresh sparse vegetables are generally boiled, sunshine, hot water washing and other methods can be used to eliminate carcinogenic purposes.

The best way to cook pickled and stale vegetables is to boil them in water, but this has an effect on the taste of the pickles. 2.Bacon and sausages are not fried Meat products such as salted meat and sausages are usually preserved and protected by the presence of nitrite, and they should not be fried, which can promote the synthesis of nitroso compounds at high temperatures, so that the carcinogens such as nitrosopyrrolidine and dimethylthiamine are high.

Therefore, it is crucial to avoid fried sausages and bacon in your daily life. Before eating, you can steam down and pour out the soup to reduce the amount of nitrite. 3.

Salted fish is boiled first Salted fish also contains more nitroso compounds, so it is best to boil it in water before eating, or steam it, and the soup should also be removed. However, some people use sunlight irradiation to think that it can remove nitroso compounds on the surface of the fish, but it does not cause much damage to carcinogens in the deep part of the fish. When eating, it should also be accompanied by some fresh fruits and vegetables.

Shrimp skin and dried shrimp contain volatile nitroso compounds such as dimethylnitrosamines, so it is best to boil them in water before eating, or directly expose them to the sun for 3 6 hours, which can also achieve the purpose of eliminating and reducing carcinogens. Fresh fruits and vegetables are rich in vitamin C, which helps protect against the harmful effects of N-nitroso compounds, and can be eaten in conjunction with these foods.

Eat fresh vegetables, fruits, and meats, and skip overnight dishes.