Many people think that the nutrition of canned food is even worse. But this is not accurate.

The production of cans is actually not complicated. The basic process is as follows: firstly heat the contents (food) and kill all the microorganisms; then fully heat the packaging containers (cans, bottles, etc.); then put the sterile food into a sterile container. In the end, the heat is sealed; finally, the heat is sterilized. After cooling, the volume of the air in the headspace of the container shrinks, and a negative pressure is generated. The originally sealed bottle can not be opened, and the bacteria outside cannot enter. In this way, the microorganisms inside are killed by high heat, and the outside microorganisms cannot find the door to enter, and the food will of course not be corrupted. If the sterilization is thorough enough, the seal is strong enough, not to mention two years, three years will not be bad, naturally no need to add preservatives.

Making cans to heat the food twice will definitely lose some nutrients, but this loss may not be as big as everyone thinks.