The preservation method of canned fruits mainly relies on strict processing techniques, including sealing, exhaust, and heat sterilization, which work together to ensure long-term preservation of the food without the need for preservatives. The specific introduction is as follows:

Sealing: Canned food uses strict sealing technology during the production process to ensure that the food inside the container is isolated from the outside world, preventing microorganisms and oxygen from entering the interior of the container. ‌

Exhaust: By heating the exhaust, vacuuming, or filling a mixture of nitrogen and carbon dioxide gas, the oxygen content in the container is reduced, reducing the possibility of microbial growth. ‌

Thermal sterilization: using heat treatment technology to kill microorganisms inside containers, usually by heating to a certain temperature (usually below 100 ℃ for acidic foods such as fruits) to sterilize. ‌

These measures work together to enable canned food to be stored for a long time without preservatives, typically for 1-3 years at room temperature. In addition, the packaging containers for canned food must be safe, non-toxic, and have good corrosion resistance and sealing to ensure the quality and safety of the food. ‌