Cold salad can not be eaten overnight, because it is easy to breed bacteria and toxic and harmful elements, affecting health. If you put a sealed fresh-keeping box in the refrigerator and take it out for heating, you can eat it, because it is not easy to breed bacteria and toxic and harmful substances.

But don't eat cold dishes and other overnight dishes, because after a night of bacterial decomposition, the vitamins in vegetables are basically lost, which will produce toxic nitrite.

Every summer, the number of patients with infectious diarrhea such as enteritis and dysentery will increase significantly, which has a lot to do with improper production methods of cold salad or eating cold salad that has been preserved for too long.

Some people think that putting cold salad in the refrigerator can prolong the shelf life, but in fact, low temperature can only inhibit the life activities of some bacteria, thus delaying the deterioration of food and not directly killing bacteria. And some bacteria especially like this low temperature environment.