Canned four "buzz" nutrition and "plus and minus"

Canned food is a bit of an editorial note: Twenty years ago, all kinds of canned foods were a favorite of many people: yellow peaches in glass jars, luncheon meat in tin cans... and when we remembered, we could just swallow. In recent years, fresh foods have been enriched, and from time to time there have been “rumors” that canned foods have no nutrition and preservatives, allowing the cans to gradually move away from our lives. Is it safe to eat canned food? In this issue, we invited Liang Zhongkang, Chairman of the China Cannery Industry Association, Shao Yunlong, Secretary-General of the China Canned Industry Association, Director of the Senior Nutrition and Food Special Committee of the Chinese Gerontology Society, and Cai Caitong, Member of the National Food and Nutrition Advisory Committee; Fan Zhihong, Associate Professor of China Agricultural University To unveil the truth of canned nutrition for everyone.

The preservative scraps are not nutritious or not fresh. Four major “squeaky” feelings: “Canned cans have a lot of preservatives and are harmful to human health. Can we put on a year or a half?”

Fact: Cans can be stored for long periods of time without deterioration, thanks entirely to sealed containers and strict sterilization, and have nothing to do with preservatives. The reason for canning is very simple: first heat the raw materials to fully kill all the microorganisms; at the same time, heat the cans thoroughly; then put the sterile foods into a sterile container and seal them with heat; finally heat sterilization again. After cooling, the volume of the air inside the container headspace shrinks, and a negative pressure is produced. The originally sealed bottle is even harder to open, and bacteria outside cannot enter. After these procedures, the food naturally does not corrupt, so there is no need to add any preservatives. According to Hao Jun, secretary-general of the China Food Industry Standardization Technical Committee, “preserved cans contain preservatives”, which is actually a prejudice against canned food and is misleading to consumers.

Lyric 2: "The cans are made from scrap."

Fact: In fact, canned goods are of high quality and good appearance. For example, most of the canned fruits are glass bottles or transparent soft packaging. Everyone can directly see beautiful and complete oranges, yellow peaches, hawthorns, pineapples and so on. As for cans that do not see “content”, if quality raw materials are used, it is likely to affect the quality of a batch. Few manufacturers will take this risk. Finally, China is a big producer of canned food in the world. Its products are exported to the United States, the European Union, Japan, and other countries in the world, with an export volume of 3 million tons. The censorship of food products in these countries is particularly stringent. Canned food in China can be so popular in the international market that it can confirm the excellent quality of canned food.

Lyrical three: "Canned food is convenient, no difference with instant noodles. Can only hunger, no nutrition."

Fact: The canning process is very simple and generally only requires heating. More importantly, the heating temperature for making cans is not too high, and sometimes it is lower than the temperature for cooking in the house. Therefore, to a certain extent, canned nutrient loss is less than that of home cooking. In general, using pasteurization, the processing temperature for canned meat and seafood can not exceed 120°C; the processing temperature for canned vegetables and fruits does not exceed 100°C; and our daily home cooking The temperature will easily exceed 200 °C.

Lyrical four: "canned food, no matter how safe and nutritious, as long as it is processed, it is always not new!"

Truth: First, the raw materials used for canned foods are fresh. To make canned foods, the most fresh ingredients are selected in the most suitable season for lower costs and better taste. Moreover, in order to save costs, regular canners have their own raw material bases and build the production line closest to the base. In this way, it is equivalent to “do it now” from its own backyard, which greatly shortens the process from picking, transporting to processing.

Although we can easily buy "fresh" fruits from all over the country, they just look fresh and nutrients are constantly being lost. Because any fruits and vegetables continue to "breathe" after picking, some nutrients will continue to decrease. The canned fruit can not exceed 6 hours from the process of picking and processing of raw materials. High-temperature heat treatment will stop or slow the chemical reaction of nutrient loss, and maintain the freshness and nutrition of food. Taking yellow peach as an example, after 1 day of picking, vitamin C will lose 30%, while yellow peach can only lose 10%. Therefore, the canned fruit is fresher than the "fresh" fruit that is transported long distances.

The elderly eat canned fish. Children who eat canned fruit can eat two or three canned foods per week. They have been very popular abroad. In 2009 alone, Americans consumed canned food worth $25.4 billion.

In the United States, cans are stored in the kitchens and basements of every household. They think that this is an essential reserve for disaster prevention and emergency response. And, for very "lazy" Americans, canning is a good helper for cooking. For example, canned fish can easily be used for hamburgers, sandwiches, and salads; canned tomatoes can be used to make a variety of tomato-flavored soups, stews, and pizzas; canned fruit can be used for dessert pies and desserts; and convenient canned vegetables can be saved. Going to the trouble of peeling and cleaning, it is very good for baking, steaming, and making salads. Chinese nutrition experts believe that canned foods are best eaten only two or three times a week, with different emphasis on different people.

The old man can prepare some canned fish. Fish is rich in nutrients, but it is troublesome because it also has thorns, making it inconvenient for older people to eat. Canned fish can solve this problem well. Because the bones of canned fish are already very crunchy, and calcium is dissolved in large amounts, it is easier for the elderly to eat.

Office workers are suitable for canned vegetables. Office workers live at a fast pace and do not have enough time to eat enough vegetables. Canned vegetables are very convenient to eat, with a point of ham, eggs, meat, you can make a balanced meal, such as corn green beans ham fried rice, corn glutinous rice, quail balls and so on.

Children can eat canned fruit. Studies have shown that canned fruit and fresh fruit have little difference in nutrients, but because sugar is high, it is not suitable for the elderly, but it is suitable for children. First, fruit cans are relatively soft and suitable for children with poor digestion. In the second place, many naturally fruity fruits, such as yellow peaches, are sweet and delicious when processed into cans. In fact, the fruit yogurt that we eat is also used as canned fruit, so that the taste will not change, and it is not easy to degenerate. Canned fruits can not only be eaten directly, but also can easily make delicious: Peach Yogurt, Sydney Tangerine Tremella soup, candied hawthorn mixed cabbage heart and so on.

The housewife picks up novelty cans. Housewives can buy exotic cans of raw materials, as long as simple ways can make "innovative dishes", such as white asparagus, chickpeas, olives and so on.

Canned nutrition "plus and minus"

The nature of different nutrients is different. After food is canned, their vitamin content changes.

Carotene, lycopene, and calcium increase. Both carotenoids and lycopene are very stable to heat and therefore will not be lost. And after heating and cooking, their absorption rate will increase greatly. The process of making canned foods will also play a role in “concentration,” so carotenoids, lycopene, etc. will not only not be lost but will also increase. Studies have shown that the content of carotene in canned carrots is 50% higher than that of fresh carrots, and the content of lycopene in canned tomatoes is twice as high as that of fresh tomatoes. Minerals are not afraid of heating, so the content will not fall, and sometimes it will increase. Take canned fish as an example, because during the production process, the fish bones become soft and soft and dissolve a lot of calcium, so the calcium in canned fish is more than twice that of fresh fish!

No loss of protein and dietary fiber. The heating temperature of the cans does not exceed 120°C, which is similar to the temperature of burning braised pork with a pressure cooker in the home. Therefore, the nutrition of proteins, minerals, dietary fiber, etc. can be well preserved.

Acid foods have less vitamin loss. There are only a few vitamins that can really be lost in canned foods, especially vitamin C and folic acid. However, the nutritional losses of different canned foods are not the same. Acidic foods usually have relatively small losses, such as tomatoes. Near-neutral food losses, such as peas and spinach, are greater, while meat loss is mainly thiamine.

Four-step selection of high quality cans. Do not have "oil trademark." Observe whether the packaging is complete, whether there is any leakage, whether the lid, cap is rusted or scratched, and whether the trademark is immersed in oil.

2. Do not buy "fat". Observe the bottom, lid or cap. Can lids and caps are slightly concave. Do not buy if you find that the lid and lid are protruding outward.

3. The sound is crisp and bright. When the shell lid is snapped by hand, the sound is crisp when the sound is brittle, and it is degraded when the sound is dulled.

4. The trademark must be complete. Observe the product's production date and shelf life. Products that are incomplete or near the shelf life must be purchased with care.

Store in a cool place. Canned food can not degenerate at room temperature for a long period of time. However, it cannot be placed anywhere. New research confirms that if the cans are kept at room temperature for a long time, both essential amino acids and vitamins will be slowly lost.

Therefore, canned food should be stored in a cool place. If you can put it in the refrigerator, the loss of nutrients is basically negligible.