These 4 overnight dishes are too dangerous, it is better to waste them than to eat them! They can damage the liver and kidneys and the intestines...

This article was reviewed by Pa Li Ze, chief physician of nutrition, member of the Science Popularization Committee of the Chinese Nutrition Society

It is said that "thrift is a traditional virtue of the Chinese nation", but when faced with leftovers at home, many people are in a dilemma: throw it away, it is a waste; heat it up and eat it the next day, but words like "excessive nitrite", "carcinogenic", and "poisoning" make people worry...

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Can we still eat leftover food? Which dishes should be thrown away without hesitation, and which can be saved for the next meal? How should we deal with leftover food scientifically? Today, the editor will answer them one by one for you~

01

Overnight food contains nitrite

Is it toxic and carcinogenic?

First of all, we need to make it clear that the so-called "overnight food" does not simply refer to the food left over from the day of the meal and left for the next day. Scientifically speaking, food that has been left for more than 8-10 hours is considered overnight food.

The longer the food is stored, the higher the nitrite content will be. Many people are always worried that eating food will cause nitrite poisoning or even cancer. Is this really the case?

Nitrite itself is not carcinogenic

In fact, nitrite itself is not carcinogenic. It is widely present in the natural environment, especially in food. For example, the average nitrite content in vegetables is about 4 mg/kg, meat is about 3 mg/kg, and eggs are about 5 mg/kg. After being picked and harvested, vegetables and fruits will continue to produce nitrite.

In addition, nitrite is also a legal food preservative. As long as it is within the national food safety standards, there is no health risk. For example, nitrite may be added to the pickled foods such as ham and bacon that we often eat in our lives.

Under certain conditions, nitrite is toxic.

However, it is not entirely groundless that people always say that overnight food is toxic and carcinogenic:

On the one hand, if excessive intake of nitrites in a short period of time, it will cause acute poisoning, affecting the functioning of red blood cells and making the blood unable to transport oxygen. In mild cases, symptoms may include dizziness, weakness, chest tightness, shortness of breath, nausea and vomiting, abdominal pain and diarrhea, and blue lips and fingertips; in severe cases, it may lead to brain hypoxia and even death.

On the other hand, when nitrite enters the acidic environment of the stomach, it will react with the protein eaten to produce nitrosamines, which are truly carcinogenic. Long-term and large-scale consumption may cause cell mutations and even induce gastric cancer, esophageal cancer, liver cancer, colon cancer and other cancers.

Does the nitrite content in overnight food exceed the standard?

According to relevant domestic research reports, the minimum toxic dose of oral nitrite for adults is about 300mg-500mg, and ingestion of 1-3g can cause death.

What does this mean? Generally speaking, overnight food stored in the refrigerator for 24 hours (excluding pickled vegetables and processed meat) will not contain more than 10 mg/kg of nitrite.

Therefore, the nitrite content in overnight food is far from the toxic dose. It is not a big problem to eat a little occasionally. There is no need to be afraid of overnight food. The key is the frequency and amount of eating.

02

These 4 overnight dishes are too dangerous

It’s best to throw away any leftovers!

So, can we eat leftover food without any worries? No!

This is because during the storage and reheating of overnight food, not only will some nutrients be destroyed and lost, but it will also easily breed bacteria, which can easily cause gastrointestinal discomfort or even food poisoning after consumption. In particular, the following four types of overnight food are more harmful to the body and should be thrown away if not finished:

Overnight vegetables

Eating vegetables regularly has many benefits. According to the "Dietary Guidelines for Chinese Residents", adults should eat 300 to 500 grams of vegetables every day. But there is an old saying: "It is better to have leftover meat than leftover vegetables."

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If vegetables are left for too long after being cooked or are improperly stored, a large amount of nitrite will be produced due to the decomposition of nitrifying bacteria, and the content in the leftovers is likely to reach the severe limit.

Zhejiang Ningbo Food Inspection Institute once conducted an experiment and found that green leafy vegetables such as celery, lettuce, and water spinach, after being fried and stored at room temperature of 25°C, had an astonishing nitrite content of over 100 mg/kg after 24 hours.

It is strongly recommended not to eat green leafy vegetables overnight.

Overnight seafood

It is difficult to completely eliminate the various bacteria that may exist in seafood products such as shrimps and crabs using general cooking and eating methods. If they are not cooked while fresh and eaten in time, they may become corrupt from the inside out!

If you do not finish the food on the same day and eat it overnight, it may cause bacteria to multiply and produce bacterial toxins, which may cause damage to liver and kidney function.

Overnight Tremella Mushroom

Many people will stew a pot of Tremella soup and put it in the refrigerator to eat several times. But this practice is actually very dangerous!

Generally speaking, the nitrite content of dried Tremella and mushrooms, whether grown indoors or collected in the wild, is lower than that of vegetables. However, if they are soaked at room temperature for too long, or left for a long time after being cooked, not only will the production of nitrosamines increase after consumption, but they will also be more likely to breed bacteria. If they are improperly stored, there is a possibility of the production of bacterium toxins, which will cause abdominal pain, diarrhea and other symptoms after eating.

[Tips]: It is okay to seal the Tremella soup and refrigerate it for 1-2 days; but if it is more than 3 days, it is best not to drink it; and if the leftover Tremella in the bowl is not refrigerated, it is best not to eat it the next day.

Overnight soft-boiled eggs

Many people prefer to eat half-cooked "soft-boiled eggs" rather than fully cooked white-boiled eggs. However, these half-cooked eggs are not sterilized thoroughly and may contain a variety of pathogenic bacteria such as salmonella; if left for a long time, it is easier for bacteria to grow, which will harm the intestines after consumption.

[Tips]: If the eggs are cooked for the first time and stored at a low temperature and in a sealed environment, it is generally okay to eat them overnight.

03

Scientific storage of leftovers

Eat more safely

Generally speaking, it is best to cook as much food as you can eat. If you cook too much and cannot finish it, you can follow the following 4 points to deal with the leftovers:

I would rather leave some meat than some vegetables

When there are bound to be leftovers during a meal, vegetables should be eaten first, and any leftover meat or non-vegetarian dishes can be saved for the next meal. For details, please refer to the following storage time ranking:

Green leafy vegetables: storage time 0 days (salad vegetables should be eaten as soon as possible);

Staple food: storage time 1 to 2 days;

Meat dishes from livestock and poultry: The storage time shall not exceed 3 days.

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Refrigerate while hot

The longer leftovers are left at room temperature, the greater the risk of bacteria growing; moreover, some of these bacteria produce toxins that may not be killed by normal home cooking.

Therefore, when the dishes have cooled down to a temperature that is not too hot to touch, you can pack them in fresh-keeping containers and put them in the refrigerator. Don’t wait until they are completely cold before putting them in the refrigerator.

The location of leftovers in the refrigerator is also crucial

① The upper layer of the refrigerator area: leftovers and other cooked food can be placed;

②The middle of the refrigerated area: suitable for fruits and vegetables;

③The constant temperature refrigerated area at the bottom: can be used to store eggs, dairy products, soy products and meat to be eaten that day.

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Keeping raw and cooked food separate can prevent parasites and bacteria carried in raw food from falling onto cooked food such as leftovers when eating, thereby reducing the risk of cross infection.

Reheat thoroughly before eating

Leftovers must be thoroughly heated before eating, especially meat. Thorough heating means heating the entire dish to 100°C and keeping it boiling for more than 3 minutes.

To avoid uneven heating, you can use tools such as chopsticks and forks to look inside the food to make sure it is heated thoroughly before taking it out of the pot.

Source: I am a great doctor official account

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