catalogue
1. Invention history
2. Production key
3. Opening method
4. Canning area
5. The law of eating
6. Terror rumors
1. Invention history
Invented in 1809, Napoleon's soldiers starved to death because they could not eat fresh vegetables, fruits and other foods during the crusade. What shall we do? The French Napoleon government used the huge bonus of 12000 francs to find a way to store food for a long time.
Many people devote themselves to research activities in order to win prizes. One of them, a Frenchman named Appel, managed candied food, worked as a worker in a pickle factory, a winery, a candy store and a restaurant, and later became a chef. When selling fruit pulp, wine and other foods, he found that some often go bad, and some are not easy to go bad. He also happened to find that food sealed in glass containers would not go bad if heated properly, which greatly inspired him. Therefore, Appel responded to the government's reward and specially studied the method of preserving food.
After ten years of hard research, he finally succeeded. His method is: put the food in a jar, put it all in a boiling pot, heat it for 30 ~ 60 minutes, plug it with a cork while it is hot, and then reinforce it with thread or seal it with wax. In this way, food can be preserved for a long time without spoilage. This is the embryonic form of modern canned food.
In this way, the earliest cans appeared. Abel was rewarded by the French government and warmly welcomed by the sailors.
Shortly after Appel's glass jar was improved, an Englishman, Peter Duran, specially made tinplate jars and obtained a patent in Britain. /kloc-At the beginning of the 9th century, canning technology spread to the United States, and canning factories appeared in Boston and new york. 1849, American Henry Evans opened an unprecedented cannery. 1862, French biologist pasteur published a paper pointing out that the main cause of food corruption is the growth and reproduction of microorganisms. Therefore, the cannery adopts steam sterilization technology to make canned food reach the commercial aseptic standard.
China's method of canning food was applied to the people as early as 3,000 years ago in China. The earliest agricultural book, The Book of Qi Yaomin, recorded that the meat of livestock was cut into pieces, mixed with salt and wheat flour, and then the head was sealed with dense mud in porcelain. Although it is different from modern canned food, it is the same.
2. Production key
Canned food generally prevents food from spoilage through three ways of synergy: both food and canned food need to be sterilized, and after bacteria and bacterial spores are eliminated, there will be no bacterial reproduction. But it is unlikely to be completely eliminated. What we can do is to basically sterilize and prolong the preservation time of food as much as possible.
There are also a lot of bacteria and bacterial spores in the dust in the sealed air. Spores of bacteria are like seeds of trees, which are difficult to make and can float in the wind. So the can is vacuum sealed.
Canned food contains preservatives, because bacteria can multiply rapidly in a suitable environment. Even if there is only one bacterium, it will soon become countless because of its fission and reproduction. Preservatives can effectively inhibit the survival of bacteria, so that a few bacteria can not survive, and food will be preserved for a long time.
There are two commonly used food preservatives: sorbate and nitrite, of which sorbate is basically non-toxic, but nitrite is a carcinogen, which is a big problem.
The Hygienic Standard for Food Additives stipulates that no additives can be added to canned fruits. However, some inferior cans were added with synthetic pigments such as potassium sorbate, carmine and lemon yellow, and coconuts were bathed with sweeteners, industrial caustic soda and industrial hydrogen peroxide.
3. Opening method
Sometimes it is not easy to open cans, and it is still dangerous to use tools. It is easy to open cans with a little knowledge of physics: 1. Inverted cans. 2. pat the bottom hard with your hand twice. Bring the jar here and open it with a slight twist.
4. Canning area
Canned food maintains a global production capacity of 40 million tons every year. In China, canned food is a traditional export commodity. According to Liang, chairman of China Canning Industry Association, the main producing areas of canned fish in China are Guangdong, Fujian, Zhejiang, Liaoning and other coastal areas. Canned citrus is mainly produced in Zhejiang and Hunan. Canned meat is mainly produced in Shanghai, Fujian and Sichuan. Canned peaches are mainly produced in Hebei; Canned mushrooms and asparagus are mainly produced in Fujian, Shandong and Yunnan. Tomato paste is mainly produced in Xinjiang; Canned bamboo shoots are mainly produced in Zhejiang, Fujian and Jiangxi. The regionalization of canned product distribution makes the canned industry closely integrated with local industries and helps to stimulate local economy.
In 2007, the canned food output in Shandong reached 483,300 tons [8], up 36.16% year-on-year; Canned sales revenue reached 8.264 billion yuan, of which canned aquatic products revenue reached 854 million yuan, up 38.63% year on year, and canned fruits and vegetables revenue reached 66 1. 1 billion yuan, up 5 1.69% year on year. It is understood that canned food production in Shandong is mainly distributed in Yantai, Weihai, Linyi and Heze, forming three main producing areas: canned asparagus in Cao Xian, canned fruit in Pingyi (mainly produced in the local town of China) and canned seafood in Rongcheng. The canned food production in these three producing areas accounts for more than 50% of the whole province. Among them, the output of canned asparagus in Cao Xian ranks first in the country, which is mainly sold to the international market; Pingyi is one of the three largest canned fruit producing areas in China [9]; Rongcheng enjoys a high reputation in the international market for producing high-grade canned seafood.
More than 140 countries and regions are exported every year, covering five continents. The main markets are Japan, the United States, the European Union 15 countries, Russia, ASEAN countries and the Middle East.
5. The law of eating
Eating in moderation is healthier. Everything should be measured, and canned food is no exception. Although canned food is nutritious and delicious, don't forget your balanced diet. Don't give up these fresh foods when vegetables and fruits are very rich in season; If you are not so busy, you should always cook some meals for yourself and your family to warm your stomach and family.
Don't blindly pursue big packaging. Winners in supermarkets have the habit of buying large packaged foods, which is both worry-free and cost-effective, and may not be a good thing. Canned food can be preserved at room temperature when it is unopened, but once it is opened, it is as easy to deteriorate as other foods. If you open a can and don't finish it, be sure to put it in the refrigerator as soon as possible. Don't think that food in cans can be kept sterile without packaging. Therefore, it is wise to choose the right amount of edible packaging.
One of the most important benefits of canned food is that it can provide uncommon fruits and vegetables or fish, such as horseshoe, asparagus, tuna, shad and so on. These foods are excellent raw materials for cooking dishes. With canned food, we can make these good dishes anytime and anywhere. However, it should be noted that the canned food is cooked during the processing, so just touch the canned food when cooking. If cooking time is too long, it will undoubtedly lose more nutrition.
The selection of cans from famous brands and enterprises is very standardized from raw materials to processing, and there is no problem in safety, hygiene and nutrition. Many famous brands, such as Public Opinion, Merlin, Cologne, Eagle Money, Zhaobao and Yinlu, are all good choices. On the contrary, in order to make huge profits, those small workshop-style canneries use unqualified raw materials and lack the basic knowledge and technology of canning, so they add preservatives, pigments and even other harmful additives in violation of standards. Careful observation of packaging is unfamiliar with canned brands, and you are worried that you can't distinguish defective products? It doesn't matter, observing the outer packaging of cans is a very simple way to distinguish. First look at whether the outer packaging is neat and clean, and whether the handwriting is printed clearly. In addition, the label of canned food produced by regular manufacturers should be marked with product name, factory name, address, ingredient list, net content, solid content, implementation standard code, quality grade and shelf life. Finally, don't forget to look at the production date and buy the products within the warranty period. Carefully identify the quality. Next, check the quality of the cans themselves. Canned fish and meat: Most of these cans are tinned. Because the inside of a good can is vacuum, the top or bottom of the can should be flat or concave. For those cans that are air-tight or improperly sterilized, there are still bacteria in the cans, which will produce gas, so the top or bottom of the cans will bulge, so the cans can no longer be eaten. Canned vegetables and fruits: Most of these cans are packed in glass bottles, and the contents can be seen. A good can should have even contents and clear soup. The contents of bad cans vary in size, and the color of soup will be much heavier.
High quality canned food 1. Check the packaging. Observe whether the outer packaging is neat and clean, whether the handwriting and printing are clear, whether it is within the shelf life, and whether the food label is marked with information such as company name, address and contact number. 2. Check the endoplasmic reticulum. For products packed in glass bottles, we can observe whether the shape of the contents is complete, whether there are foreign bodies and turbidity. Normal products have a certain degree of vacuum, and there will be a crisp sound when knocking on the bottle cap. If there is no vacuum, the product is more likely to have quality problems. 3. prevent fat listening. Don't buy products with changed appearance. When canned food is contaminated by microorganisms and loses its edible value, it often produces the phenomenon of fat hearing of products, that is, the volume of outer packaging increases. 4. Choose genuine products. Consumers should try to buy products produced by regular enterprises or enterprises with a certain scale in the main producing areas in reputable shopping malls, and try not to buy products listed in shopping malls for price reduction.