Why do canned foods have a shelf life of several years?

What causes us to be unable to preserve food forever in boxes?

Anyone can ever bring fear of a massacre: it could be a nuclear disaster, zombies . And in every movie about the people who survived after the disaster ended, Canned food always plays an important role. For those who are less worried about apocalypse, canned food is also a great choice for long-term camping or storage.

Canned food is also a great choice for camps.

However, what many people do not realize is that canned food does not remain the same forever . Canned food can be stored for 5 years or even decades but there are some final factors that still cause them to fail. The question is why can't it exist forever? What will eventually make canned food broken?

Canned food must not remain the same forever.

Answer : Canned food that is properly disinfected, processed and preserved will not break, although the taste may change over time. However, excessive humidity, temperature, sunlight and other factors can affect the integrity of the box itself and the food contained therein.

Why can canned food be stored for a long time?

When the food is boxed, it is put in a completely new, clean box and then sealed. Food was initially strictly tested, but there was one final step where all the magic came from here. After cover is covered, food starts to be cooked. Heated bacteria and other pathogens that are heated exceed certain temperatures (usually the boiling point of water - 100 degrees Celsius), they will be disabled or killed. After the box is closed, in theory no bacteria or spores get into the food inside the box. So after a few months, years or even decades, when you open the box, you can see that the food is still relatively fresh.

By eliminating microorganisms, humans can keep the quality or ingredients of food unchanged.

Food is broken by microorganisms that come into contact with food, through the air or other things that touch food. Small creatures (such as bacteria or fungi) also need to eat like humans and all other living things. When they are on food, they eat and release waste like any other creature. People cannot digest waste from microorganisms and then food often smells bad (at this point we consider that the food is broken). By eliminating microorganisms, such as canning process, people can keep the quality or ingredients of food unchanged.

How can food be damaged?

Despite being the best source of preventive food, there are still a number of factors that can affect the quality of canned food. If your underground cellar or basement is wet, or if the box gets wet, oxidation and hydration can make the box start to rust. Even without rust, oxidation can open the door for microorganisms to enter the food inside. At that time, the party starts and the food will gradually be damaged or reduced by small organisms.

Some foods after a while will begin to break down and occur chemical reactions between its components.

If a box is broken, bent or dropped, its tightness will be affected making the bacteria easy to penetrate. Moreover, despite the disinfection process, some foods can still contain inactive spores of microorganisms that the ripening process cannot completely eliminate. If it is possible to be exposed to sunlight (or temperature), the air inside the box will expand and the temperature increases also create an ideal environment for microorganisms to reproduce and grow. This is not common but can certainly happen. So make sure you keep the food in a cool, dry and dark place.

Some foods after a while will begin to break down and occur chemical reactions between its components, especially when there is high acid content in food. Although this is not the same as the way food is damaged by bacteria, it can change the taste and make you no longer feel good when enjoying it. It doesn't necessarily make you sick, but you will definitely lose an interesting eating experience.

There is no 100% guarantee that the sterilization and canning process will prevent all microorganisms from entering the box.

Finally, there is no 100% guarantee that the sterilization and canning process will prevent all microorganisms from entering the box. Canned food manufacturers have a strict control process but home-based canning methods (which are becoming increasingly popular) are far from meeting these standards.

If you want to keep yourself safe from pathogens caused by spoiled food or food, just be a bit careful. First, check if the box is intact. If it's still okay, open the box and see if there are any signs of growing microorganisms on the food surface or lid. Finally, taste the food to see if its flavor is normal. If there is any doubt during the test, boldly remove the food box.