Overnight dishes (take-away cooking), especially green leafy vegetables, are not recommended. Even if it is preserved, it will produce carcinogens. Remember to eat as much as possible next time.
Let's learn about overnight dishes:
If the fried vegetables are left for too long, or the bought vegetables are left for too long, the nitrate in the vegetables will be reduced to nitrite under the action of bacteria. For this kind of leftovers containing nitrite, it doesn't work even if it is put in the freezer.
Even if the leftovers are taken out and heated, toxic nitrite will not be removed, and the residual nitrate in vegetables will be decomposed into more nitrite under the action of high temperature. After too much nitrite enters the human body and is absorbed into the blood, the low-iron hemoglobin in the blood can be converted into methemoglobin, and the ability to carry and transport oxygen is lost, and tissues and organs cannot get enough oxygen, so the body will have symptoms of hypoxia and mild nausea and vomiting. It is not recommended to eat vegetables overnight.
How much nitrite will green vegetables produce overnight? When vegetables are just heated, high temperature inactivates reductase and kills most bacteria, so they are the healthiest to eat. Cooked vegetables are more suitable for bacterial growth. Even if it is covered with plastic wrap and put into the refrigerator, bacteria will enter when it is taken or turned, so that the content of nitrite begins to increase again.
The nitrite content of vegetables after 24 hours in the refrigerator is about 7㎎/kg. All kinds of green leafy vegetables contain different amounts of nitrate, especially the large use of chemical fertilizers now, which leads to the increase of nitrate in vegetables, so this situation is not recommended.