Chinese storytelling is often an army moving in the stomach. Food is an important factor in the war. Napoleon is one of the greatest soldiers in history, and he is deeply aware of this and offers 12000 francs to collect food that can be preserved for the army. For a long time, there are not many ways to preserve food, especially ready to eat food. A chef named Nicola Appel noticed that food packaging was heated in a bottle and could be kept for a long time without being opened. Based on this discovery, he tried and tried for more than 10 years, and finally invented canned food preservation technology. 1810, he won the prize.

The invention of canned food is one of the milestones in the history of food technology. An Englishman, Peter Durand, is promoting the development of canned technology. He invented the process of packaging food with tin cans and applied for a patent. However, he did not use the patent, but sold it to others. 1813, a canned food processing plant based on the technology has been established in the UK. In the past year, canned technology has also spread to the United States, and New York has also set up factories.

Tin cans have advantages in process and cost, but opening cans is more difficult. Tin tin's hair has been shining for decades. How to open it is a trouble. People everywhere began to design tin cans. Before 1870, there were a few ingenious designs, but they were limited to a variety of special configurations. 1870, the US William Lyman applied for canned cans patent, first stuck in the canned center and then rotated on the tin with a rotary cutting wheel. The design is ingenious, but the operation of the center is annoying first, and the product is not very successful.  1925, an American company uses "another wheel" to improve Lehmann's design to "bite" cans to avoid entering the tin shop first. Tin feeder is easy to use, safe and can be seen in the market. Since then, canned food has become more and more convenient. The current tin can only run on the tin and automatically turn on.

When Appel invented canned technology, people do not know why canned food will not deteriorate. It was not until more than 50 years later that Pasteur, a French scientist, unveiled the mystery of food corruption, and the principle of canned technology was well known. The original food is bad, is the result of bacterial growth. Bacteria are everywhere in nature, and bacteria in the air fall on food and grow from nutrients in food. Heating is an effective way to kill bacteria. When the food is fully heated, it is sealed in the bottle. The bacteria are completely killed and separated from the air. There is no bacteria entering the food, so the food can be preserved for a long time but not bad.

Many people say that when they say food with long shelf life, they must use many preservatives. This is for granted. Canned food is the core of killing bacteria, and then isolate the source, it will not "rot", in general, there is no "reverse".

The perfection of canned technology has not only been applied in the army, but also has been welcomed in the civil field. By the middle of nineteenth Century, canned food became a fashionable food, to a certain extent, a symbol of the quality of the middle class.

In the past 100 years, food processing technology and fresh-keeping technology have been greatly developed. With the development of logistics ability, canned food is no longer as attractive as before. Nevertheless, it is still the most economical solution for long-term preservation of ready to eat food. Canned foods still have a large market abroad, and many families who are unwilling to cook are eating lots of canned food all the year round. On the other hand, many family canning methods are being perfected. DIY canned foods are common in Europe and the United States, similar to those made in China.

Many people, including some nutrition experts, think that canned food is not nutritious because it needs to be heated and heated enough to destroy some nutrients. 1997, a commentary published by University of Illinois raised challenges. They compared the various nutrients in fresh fruits and vegetables, frozen fruits and vegetables, canned fruits and vegetables, and the effects of cooking and storage on these nutrients. The results showed that the contents of vitamin C, vitamin B and polyphenols in canned foods were lower than those in fresh frozen foods, but these substances in fresh and frozen vegetables and fruits, vegetables and fruits were much lower than tin lead. In addition, fresh vegetables and frozen vegetables are raw and cooked, and these nutrients are further reduced in cooking. Canned food is cooked. These nutrients will not decrease significantly during storage. They do not need cooking.