You cannot eat fried eggs with onions overnight. "Overnight dishes" do not only refer to dishes that have been left overnight. If they have been left for more than 8-10 hours, they should be considered overnight. There are two reasons for the increase in toxic ingredients in food. The first is because the chemicals in food produce carcinogens, such as nitrite, which cannot be removed even if heated. Another reason is secondary contamination by foreign bacteria during placement.

Because the process of reducing nitrate to nitrite by nitrate reductase in microorganisms is essentially a biochemical reaction, the longer the storage time, the more nitrite will be produced. Therefore, do not leave overnight dishes for too long and dispose of them as soon as possible.

Extended information:

Notes on storage of leftovers:

1. Store them in categories. Cold dishes, hot dishes, meat dishes, and vegetarian dishes should all be stored in categories.

2. It is better to leave meat vegetables than vegetarian vegetables, especially leafy vegetables. Leafy vegetables themselves contain a certain amount of nitrite, and the content will continue to increase after overnight.

3. Store dishes that are not expected to be finished in lunch boxes in advance to avoid leaving leftovers and reduce cross-contamination.

4. When eating again, it must be heated and heated thoroughly to achieve the purpose of sterilization.

5. Be sure to put it in the refrigerator and avoid leaving it at room temperature. Overnight dishes that look spoiled or smell abnormal must be thrown away.

People's Daily Online - Eating overnight vegetables is very harmful. How to deal with it without wasting it