"overnight dishes" don't just refer to dishes left overnight. If the dishes are left for more than 8-1 hours, they should be counted as overnight dishes. There are two reasons for the increase of toxic components in food. The first reason is that chemicals in food produce carcinogens, such as nitrite, which cannot be removed even if heated. Another reason is the secondary pollution caused by foreign bacteria when it is placed.

Overnight dishes have the following hazards:

1. Produce pathogenic nitrite

Overnight dishes will produce pathogenic nitrite in addition to the destruction of nutrition. This is because the longer the storage time, the more nitrite content in vegetables will increase. Although nitrite does not directly cause cancer, it has certain health risks to the body.

2. A large number of bacteria proliferate

Overnight dishes are prone to bacteria in a humid and mixed environment. Especially in hot summer, the speed of bacterial reproduction is accelerated, and overnight dishes are easily contaminated by bacteria. When people eat them again, it is easy to cause gastrointestinal diseases and even food poisoning.

Extended information:

Several methods to reduce the harm of overnight meals

1. Keeping at low temperature

in a refrigerator at 4 degrees (cold storage) can inhibit the growth and reproduction of microorganisms, inhibit the activity of nitrate reductase and reduce the production of nitrite. Many literatures have studied how the storage time and conditions of vegetables affect the content of nitrite, and the conclusion is that refrigeration can greatly reduce the production of nitrite.

2. Don't turn

Put out the dishes you can't finish in advance, and then put them in the refrigerator for preservation, instead of turning them for a long time. The more vegetables are turned, the greater the chance of being infected with microorganisms. In this way, the production of nitrite can be well controlled and the safety of leftovers can be guaranteed.

3. Reduce the storage time

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, overnight dishes should not be placed for too long, and should be solved as soon as possible.

Reference: People's Daily Online-Overnight dishes are very harmful, so don't eat these overnight dishes any more.