Canned food can be stored for a long time without preservatives

"This can has been produced for more than a year, why is it still within the shelf life? Is it still edible? Is there a lot of preservatives in it? Is this can safe?" Many consumers will be concerned about the long-term storage. Similar questions arise from canned food, but in fact canned food can indeed be preserved for a long time through commercial sterility.

Canned food refers to food raw materials that have been pretreated, canned and sealed in iron cans, glass bottles, plastics and other containers, and then sterilized to achieve commercial sterility and can be stored at room temperature for a long time. The sterilization of canned food is divided into two modes: low-acid food with a pH value greater than 4.6 should be sterilized by high temperature (about 118°C-121°C), and acidic food with pH value below 4.6, such as canned fruit, should be pasteurized (95°C-100°C).

Some people may also question whether the nutrients in the food are also destroyed after the canned food is sterilized by high temperature? Is the canned food no longer nutritious? This starts with what is commercial sterility.

According to the "Canned Food Industry Handbook" published by China Light Industry Press, commercial sterility refers to the fact that different foods after canning and sealing have different pH values and different bacteria carried by themselves. After scientific testing and strict calculation, after moderate sterilization and cooling at different temperatures and times, a certain vacuum is formed, and the pathogenic bacteria and spoilage bacteria in the can are killed through the sterilization process, and the nutrients and flavor of the food itself are preserved to the greatest extent. It has commercial value during the shelf life of the food. Therefore, the sterilization process of canned food does not kill all bacteria, but only targets pathogenic bacteria and spoilage bacteria, preserving nutrients, and the sterilization process of many foods is also a cooking process, making their color, aroma and taste better. Thicker, more nutritious and more delicious.

Therefore, the long-term preservation of canned food can be realized after pretreatment, canning, sealing and sterilization, so canned food does not need to add preservatives and can be eaten safely.