Canned food is one of the most important inventions in the history of human food industry. It is also a model for the conversion of military technology to civilian use.

Napoleon, the French emperor, opened up territory in Europe, the front was too long, in order to solve the problem of military logistics supply, he offered a reward of 12,000 francs to solve.

At that time, it was a huge sum of money, which was equivalent to a person's lifetime income.

 

 

A Frenchman, called Nicola Appel, has come up with the earliest can of food in a wide - mouth glass bottle, first steamed, and then sealed.

 

 

 

 

After that, Peter duren, the British man, invented the tin cans, which made the storage and portability of the cans further improved, and to date it is still an important logistics material for the army and expedition.

 

 

 

 

 

 

 

 

Later, the convenience, storage and nutritional characteristics of canned food were widely recognized by the community, and gradually become a popular delicacy.

A few decades ago, when visiting relatives and friends, if the canned fruit cans were sent, the owner would be very happy.

If you have canned luncheon meat, that's a luxury.

But with the development of food storage and processing and the development of processing technology, fresh food is available, people start to abandon the former partner, the most important of which is that it is "filled with the taste of preservative."

It is true that canned food can be guaranteed for half a year or even more than a year.

 

 

 

 

 

 

[commercial aseptic]

Canned fruit, vegetables, mushrooms, meat or aquatic products as raw materials, through processing, canning, sealing, sterilization and other processes.

Whether tinned meat cans or glass cans of fruit, the core is sterilization, although the manufacturing process is slightly different.

 

Canned food, all is preservative or without preservatives?

 

 

Early sterilization was done by boiling (100 degrees), then by calcium chloride solution (115 degrees), and then by high-pressure steam sterilization (121 degrees).

According to the current national standards, canned food needs to meet "commercial aseptic".

 

 

Commercial aseptic testing should be done before the cans leave the factory. By simulating room temperature storage, we can see if the cans will appear to be listening, bulging and other deterioration phenomena.

Microbial culture experiments were conducted to see if there was any possibility of microbial reproduction.

"Commercial asepsis" does not mean that there is absolutely no bacteria, but that it does not contain pathogenic microorganisms.

Some canned foods may contain a small number of non pathogenic microorganisms, but they will not breed at normal temperatures.

For example, there may be a small amount of fungal spores in the canned tomato sauce. Because of the strong acidity of the ketchup, the spores are not easy to reproduce, so the preservatives can be used.

 

 

Canned preservatives

Most canned goods do not require preservatives, but individual varieties are exceptions.

For example, canned waxberry can be added with propionic acid, canned mushrooms and canned grains can be made with nisin.

In addition to traditional cans, the industry is now more popular with soft cans. Its production process is basically similar to ordinary cans, but packaging materials have changed, common including nylon membranes, polyethylene films, aluminum foil and so on. Some are also added to preservatives according to the process needs.

It needs to be stressed that these cans have no problem even with preservatives, on the one hand, and on the other hand, on the other hand, it does not affect health according to national standards.

Canned meat (such as lunch meat) usually contains nitrite, which can be used as a preservative, but here is another function.

Nitrite can combine with myoglobin and form beautiful red, so it can protect the color.

 

 

Canned nutrition

Another reason canned food is criticized is that nutrition is destroyed. Have you ever wondered what the contents of canned food are not nutrients?

After high temperature treatment, the nutrition of canned food is certainly worse than that of fresh food, but it does not mean that there is no nutrition.

Protein, fat, mineral, dietary fiber and other nutrients do not cause substantial changes in the process of sterilization, the main loss of canned processing is vitamins, such as vitamin C, vitamin B and folic acid.

But cooking and cooking will destroy vitamins more or less, and you won't eat them.

 

 

For a long time, the biases of canned food have affected the development of the canned food in China, but the Chinese canned goods are very popular in the international market and are sold to the developed countries such as the United States, Russia, Germany and Japan.

According to statistics, Americans eat 90 kilograms of canned food a year, 50 kilograms in Europe, 23 kilograms in Japan, and only 1 kilogram in China.

In addition, safety, health, storage, easy to eat and can provide the nutrition of the human body, canned food is still playing a very important role in the fields of travel, exploration, disaster relief, military logistics and other fields.