These foods are:

Processed meat

This food should also not be reheated, as some substances used to preserve it are not suitable for microwave cooking and can cause adverse health effects.

Beets

This food is rich in nitrates and cannot be reheated because the iron it contains oxidizes. Furthermore, vegetables reheated in a microwave lose their nutrients and can also become carcinogenic.

Hard-boiled eggs

The steam generated by the appliance can cause the food to explode.

Potatoes

They can produce Clostridium Botulinum, a bacteria that can cause botulism.

Fruits

In general, they contain a lot of water. When heated, the water inside turns into steam, and the lack of a convenient outlet causes the fruit to explode.

Hot peppers

They contain a certain amount of capsaicin, responsible for the spicy flavor. This is released into the air, which can cause severe itching in the eyes and throat.

Breast milk

Microwaves do not heat evenly. Some parts may seem cool or at the right temperature, but others may be too hot and cause burns.

Rice

This is because it contains spores of Bacillus cereus, a bacteria that can cause food poisoning, and can survive during cooking.

These foods should not be reheated in the microwave because they lose nutrients, change their composition, texture, and flavor, and can even cause food poisoning.