Do canned foods contain preservatives?

In the era when material life was not very developed, canned food became a common nutritional supplement in people's daily life. Canned food allows people to eat a variety of fruits in different seasons. The biggest feature of canned food is that it can keep the ingredients fresh. Is this because canned food contains preservatives? In fact, from a health perspective, there is no necessary connection between canned food and preservatives, so why can it stay fresh for a long time?

Do canned foods contain preservatives?

Many people think that canned food does not go bad for a year or two because preservatives are added to it. In fact, this is completely wrong.

The reason why canned food can be stored for a long time without deteriorating is entirely due to the sealed containers and strict sterilization, and has nothing to do with preservatives. Canning is actually not mysterious. The principle of canning is very simple: first, heat the raw materials thoroughly to kill all microorganisms; at the same time, heat and sterilize the packaging cans thoroughly; then put the sterile food into a sterile container and seal it while hot; finally, heat and sterilize it again. After cooling, the air volume in the top gap of the container shrinks and negative pressure is generated, making it even more difficult to open the tightly sealed bottle, and bacteria from outside cannot get in. After these processes, the food will naturally not spoil and there is no need to add any preservatives.

What are canned foods?

When Chinese people eat porridge, they are used to eating a variety of canned foods, such as guar, potato gluten, fermented bean curd, seaweed sauce, etc. There are a wide variety of canned foods that are convenient and ready to eat and go well with rice.

It is a favorite of many elderly people and those who eat out. However, many people also think that canned food is full of preservatives and eating too much is bad for the body... Are canned food really that bad? Does it have to be canned to be considered canned food?

In fact, to distinguish whether it is canned food, it is not based on its container and appearance, but on its processing and production process:

Only foods that are sealed in airtight glass jars, aluminum cans or soft material containers and sterilized at high temperatures before and after packaging so that they can be stored at room temperature for a long time can be called "canned food";

Therefore, everything from aluminum cans of zucchini, potato gluten, glass jars of Chinese cabbage, kimchi, chicken essence, etc. to meat chunks and sauces in seasoning packets of instant noodles are all canned foods. And because canned foods rely on sterilization and sealing to achieve long-term preservation, they do not require the addition of additional preservatives. Therefore, many canned foods do not necessarily contain preservatives. Even if they are added, they are mostly only in trace amounts. People do not need to worry too much, but they should pay attention to their sodium intake.

When purchasing canned food, pay attention to whether the can is swollen, dented, dirty, rusted, incompletely sealed, or the vacuum button is floating, as these may cause the can to deteriorate.

In addition, unopened canned food should be placed in a cool, dry place at room temperature. It is best to eat it immediately after opening. If you cannot finish it, you should store it in the refrigerator and eat it as soon as possible to avoid the growth of microorganisms such as mold and bacteria, which may cause corruption or deterioration.

How long is the shelf life of canned food?

The former China Light Industry General Association stipulates that the shelf life of exported canned food is:

The validity period of tomato sauce seafood, fruit juice, tomato products, fruits and vegetables and other canned foods is two years;

The validity period of canned pork, beef, mutton, poultry, fried food, and jam is three years.

At the same time, it is clarified that "if the government laws of the importing country have specific requirements for the validity period of canned food and it exceeds the current period stipulated in my country, it can be handled and labeled in accordance with the requirements of the importing country. However, quality objections and claims should still be handled in accordance with my country's current regulations."

The former Ministry of Light Industry stipulated that the shelf life of canned food for domestic sale is:

Fish, meat and poultry no younger than 24 months;

Fruits and vegetables are not less than 15 months;

The China Canned Food Industry Association has issued a document stipulating the shelf life of canned food:

1. Shelf life of hard-packaged canned food: canned meat, poultry and fish produced in metal cans or glass bottles shall not be less than 24 months; canned fruits, vegetables, wheat and pasta shall not be less than 15 months; canned fried dried fruits, fruit and vegetable juice, shrimp, crab, shellfish and tomato products shall not be less than 12 months.

2. Shelf life of high-barrier soft-packaged food cans: The shelf life of various soft cans produced using high-barrier composite materials, including aluminum-plastic composite bags, plastic composite bags, paper-plastic-aluminum composite containers, plastic cups, plastic bottles, etc., is not less than 12 months.

Fried dried fruits, fruit juice, shrimp, crab, tomato sauce for no less than 12 months.