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Cuihua has always suspected that this home... Not "clean".
Especially in the summer, there are only parents and her family, but the meals on the dinner table are often the weight of five or six people. Mom sometimes reads words in the kitchen, as if she is performing some kind of ritual...
After observing for a long time, she finally plucked up the courage: "Mom, why do you always talk to yourself in the kitchen?" Still making so many meals? I always have to eat overnight dishes when I can't finish eating, and I said you won't let me. Isn't it...... Is there something you can't see at home? ”
Source: Tencent Medical Code
Unexpectedly, what came to me was a violent beating from my mother.
"What are you talking about?" I was watching my phone learn to cook new dishes, reading recipes for myself to remember. Also, do you know how hot and tiring cooking on a hot day is? I do more at a time, and the next day I can eat it when it is hot, how much work is saved! ”
Jade Flower: "... Well, Mom, you've worked hard! However, I heard that eating overnight dishes will cause cancer! ”
"What is so exaggerated, before we still have your grandparents' generation, eat so many overnight dishes, and I haven't seen any problems, just you young people are flirtatious!"
Can I eat overnight dishes? How to eat it is no problem? In fact, many people don't know.
Can eating overnight dishes cause cancer? Look at the data to speak!
The Internet rumors that overnight dishes cannot be eaten, which may cause cancer, and will also cause nitrite poisoning, making many people drum in their hearts.
The main reason why overnight dishes are worrying is because of the nitrites in them. However, is it really unsafe to eat overnight dishes? Why do some people eat it all right, but some people eat sick?
Recently, the Zhejiang Ningbo Food Inspection Institute used 30 dishes and 450 test data to solve the mystery of whether overnight dishes can be eaten.
In the experiment, 32 kinds of raw materials such as vegetables, meat, and eggs that everyone often eats were selected, and a total of 30 home-cooked dishes were made.
The picture shows 30 dishes used for the experiment
Source: "Zhejiang Online"
Subsequently, the dishes that have just come out of the pan are selected and stored in a disposable crisper box, and 5 boxes of each sample are collected. Placed in a 4°C environment (simulated household refrigerator) and a 25°C environment (simulated normal temperature environment), the nitrite content was detected at 0 hours, 6 hours, 12 hours and 24 hours after these two different storage conditions.
The experimental results are as follows:
remark:
1) The nitrite content in the 32 fresh raw materials used in this experiment is less than 1mg/kg
2) The detection limit of nitrite in this method is 1mg/kg
After reading the results of this experiment, are you confused? It's okay, next please see the lite version of the analysis!
1. All kinds of dishes stored at 4 °C, the nitrite content after 6 hours, 12 hours, 24 hours is basically the same as when it first comes out of the pot, and there is almost no risk of nitrite exceeding the standard and poisoning.
2. Various dishes stored at 25 °C:
Within 6 hours of storage: there is no change in the nitrite content in it;
After 12 hours of storage: In the "overnight dish" containing leafy vegetables, the content of nitrite has increased significantly! Among them, the nitrite content of fried cabbage even exceeds the limit of 20mg/kg of pickled vegetables specified in the nitrite residue standard in processed foods (GB2762-2017);
After 24 hours of storage: the nitrite content in meat dishes does not change much, but the nitrite content in vegetable-containing dishes is significantly increased, especially "overnight leafy vegetables", whose nitrite content is staggering more than 100mg/kg! If you eat such overnight dishes, there may be a food safety risk of poisoning with excessive nitrite.
3. Many people wonder about the overnight eggs, the nitrite content after 6 hours, 12 hours, 24 hours is basically the same as when it first comes out of the pot, so if the eggs are cooked, the overnight eggs can also be eaten.
Where does the nitrite in "overnight dishes" come from?
The junior high school chemistry teacher taught us that nitrogen fertilizer is an important fertilizer for plants. Plants absorb nitrogen from the environment to further synthesize amino acids and proteins. But at the same time, a small amount of nitrogen is stored in the vacuole in the form of nitrate, which is converted into nitrite by reductase in the plant.
That's why, vegetables are always inevitably filled with nitrates and nitrites.
Source: Stand Cool Helo
After the vegetables are heated and cooked, although there is no interference from reductase, the bacteria in the tableware and air will also come in to "stir up trouble". Some reducing bacteria, such as Proteus Morgani, E. coli, etc., will grow in large quantities under the right conditions, and it is easy to reduce the original nitrate of vegetables to nitrite [1].
Therefore, in the case of improper preservation of cooked vegetables (such as too high temperature and too long time), the nitrite in it will increase significantly.
Why is nitrite "focused on crusade"?
According to the previous analysis, it is indeed possible for "overnight dishes" to produce the carcinogen nitrite.
If excessive nitrite is consumed in the short term, it will affect the operation of red blood cells, so that the blood can not transport oxygen, resulting in headache, dizziness, weakness, chest tightness, shortness of breath, palpitations, nausea, vomiting, abdominal pain, diarrhea and lips, fingertips will turn blue, severe cases will make the brain hypoxia, and even death.
If you eat a lot of pickles, and just happen to drink milk, eat fish, and ingest some meat protein, it will break down into corresponding amines, which will produce nitrosamines when they meet nitrites in your body [2].
Nitrosamines are class II carcinogens published by the World Health Organization, and long-term intake can easily lead to stomach cancer, esophageal cancer and colorectal cancer and other diseases.
Read more medical texts: Do these factors increase nitrite in the body, which can lead to stomach cancer?
In addition, if a certain amount of nitrite is ingested in a short period of time during pregnancy, it may cause nitrite to enter the fetus, and the fetus within six months is extremely sensitive to this substance, which can have a teratogenic effect on the fetus [3].
But! Putting aside the dose to talk about toxicity, it must be playing hooliganism.
In general, the minimum toxic dose of oral nitrite in adults is about 0.3 to 0.5 g, and ingestion of 1 to 3 g can lead to death [4].
What is this concept?
Taking the highest nitrite dose detected in the overnight greens in the above experiments, if we want to eat the lowest poisoning dose of 0.3g, we need to eat about 6 pounds of overnight vegetables! Are you sure you can eat it...
Therefore, the nitrite content in the overnight dish is still far from the poisoning dose, and it is not so easy to cause acute poisoning.
So the overnight dish can be eaten with confidence and boldness?
Source: Tencent Medical Dictionary Medical Illustration
How to preserve and eat vegetables and meat?
Overnight vegetables can be eaten, but they cannot be eaten casually, the key is preservation.
Reducing the production of vegetable ria nitrate can be multi-pronged:
1, green leafy vegetables every time to buy fresh, do not buy too much at a time hoarded at home,;
2, the fresh vegetables that have not been finished are washed first, so as not to leave too many bacteria, and then packed in a fresh box;
3, cooked vegetables if you want to overnight, be sure to wrap them with plastic wrap and put them in the refrigerator for refrigeration.
As for overnight meat, from the previous experimental data, the nitrite produced is much less than overnight vegetables, and there is basically no need to worry.
But both raw and cooked meat are the favorites of bacteria. Therefore, the storage principles of meat are:
1, how much to eat and how much to do, the amount of food divided into several meals frozen;
2, overnight meat should also be wrapped with plastic wrap, "hot through" and then eaten, in order to fully sterilize.
After reading it, do you know how to eat the overnight dish?
END
bibliography
Lü Yuankai. Determination and Analysis of Nitrite Content in Overnight Vegetables[J]. Food Safety Herald, 2017(15):160-161.
[2] Zeng Yaochi , Hu Minyu . Research progress on the relationship between N-nitroso compounds and tumors in food[J].Chinese Journal of Cancer Prevention and Control,2008,15(2):151-155.
[3] LI Zhiwen , ZHANG Le , WANG Lina . Nitrate, nitrite and N-nitroso compounds and human congenital malformations[J]. Environment and Health,2005,22(6):92-94.]
Qin Pinzhang. Several Opinions on Modifying the Sanitary Standards for the Use of Nitrates and Nitrites for Food Additives[J], Chinese Journal of Preventive Medicine, 2005, 6: 150-151.
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