A few days ago, Tutu (pseudonym) and his family started to feel sick, vomited and had diarrhea after eating overnight watermelon. Parents had gastroenteritis and was hospitalized directly. Compared with Tutu, it was more severe, with anemia, anuria, and renal failure.
This shocked people who saw the news. Just eating a watermelon overnight, could it really have such serious consequences? But it would be too wasteful to throw away the leftovers like this, right?
Regarding leftovers, what everyone has heard most is that nitrite exceeds the standard and can cause cancer. However, we searched for some information and some experimental results and found that things may not be that simple.
1. The conditions and principles of nitrite poisoning
First, let’s take a look at the scientific definition of “ overnight dishes ”. It refers to dishes that have been left for more than 8-10 hours after cooking, and are not just leftovers from the previous day. vegetable.
Secondly, there are a lot of nitrites in the natural environment, especially in vegetables, meat, eggs and other foods, with an average content of about 3-5mg/kg. After fruits and vegetables are picked, they will continue to produce nitrite. And the longer it is left, the more nitrite content will be in the food.
In addition, nitrite is also a kind of food preservative. When adding it, as long as it abides by the national food safety standards, there will be no problem. For example, nitrite is added to some pickled foods.
Although nitrite itself is not carcinogenic, if too much nitrite is taken in at one time, it will affect the transport of oxygen by red blood cells , causing acute poisoning , with symptoms such as dizziness, chest tightness, nausea, abdominal pain and diarrhea, and It may deprive the brain of oxygen and may lead to death in severe cases.
In addition, the stomach is an acidic environment. If nitrite reacts with the protein in the stomach, nitrosamines will be produced. Nitrosamines can cause cancer. If consumed in large amounts for a long time, it may cause cell mutations and eventually induce various cancers such as gastric cancer, esophageal cancer, and intestinal cancer.
Research shows that adults will be poisoned if they take nitrite orally at a minimum of 300mg-500mg, and will die if they take 1-3g orally.
Generally, if overnight vegetables are stored in the refrigerator compartment for 24 hours, the nitrite content will still be less than 10mg/kg. There is still a big gap compared with the toxic dose.
Therefore, it doesn’t matter if you eat overnight dishes occasionally. Don’t eat them for a long time, and don’t eat a lot at one time.
2. It is best not to eat these 4 overnight dishes
In addition to the effects of nitrite, overnight dishes also have other hidden dangers.
Overnight meals will cause destruction and loss of nutrients when reheated, and bacteria can easily breed during storage, causing gastrointestinal discomfort or even poisoning.
Especially the following four kinds, it is best not to eat them:
1. Overnight vegetables
Experiments have found that stir-fried water spinach , lettuce and other green leafy vegetables are left at 25°C for 24 hours. Afterwards, the test found that The nitrate content reached more than 100mg/kg.
Therefore, cooked vegetables cannot be left for a long time. If stored improperly, a large amount of nitrite will be produced.
strongly advises against consuming overnight leafy greens.
2. Overnight seafood
shrimps, crabs and other seafood may contain various bacteria, and it is difficult to guarantee complete sterilization with general cooking methods. Therefore, it should be cooked and eaten while it is fresh, otherwise it may start to spoil from the inside, leading to deterioration.
Over time, bacteria will multiply and produce toxins, which will cause great damage to liver and kidney functions.
3. Overnight mushrooms
Under normal circumstances, the nitrite content in processed finished products Tremella and mushrooms is lower than that in vegetables.
However, if it is soaked for a long time at room temperature, or left for a long time after being cooked, it is easy for bacteria to breed, and it may also produce flavibacterium toxins, which can cause abdominal pain and diarrhea after eating. In addition, eating mushrooms soaked for a long time will also promote the production of nitrite amine .
suggestion: Seal Tremella Soup and store it in the refrigerator. Eat it as soon as possible within 1-2 days. If it exceeds 3 days, it is best not to drink it.
4. Overnight " soft-boiled eggs "
This type of soft-boiled eggs is not completely sterilized during the production process. If left for a long time, it is easier for bacteria to breed, and it will cause damage to the intestines after consumption.
3. How to store scientifically and with more peace of mind
1. Put it in the refrigerator in time
Leftovers can easily breed bacteria at room temperature, and some bacteria produce toxins that are difficult to eliminate with ordinary cooking methods. Therefore, pack them in fresh-keeping boxes and put them in the refrigerator in time. Don't wait until they are completely cool.
In addition, the shelf life of staple food is 1-2 days; the shelf life of meat and vegetables is generally not more than 3 days.
2. Place them separately
When storing food in the refrigerator, it needs to be placed in layers to avoid cross-infection by parasites or bacteria.
For example, leftovers and cooked food can be placed on the upper level of the refrigerated area; vegetables and fruits can be placed in the middle; dairy products, soy products, eggs, and raw meat can be placed on the bottom level, but they must be eaten on the same day.
3. Reheat thoroughly before eating
Leftovers, especially meat, must be thoroughly heated before eating, that is, boil the pot for at least 3 minutes.
If you are not sure whether the food is heated through, you can use a fork or chopsticks to split the food and make sure it is heated through before taking it out of the pan.
Finally, I recommend that you eat as much as you want and cook as much as you want. I hope everyone can eat safely, freshly and healthily.
