There is a scene in the movie "I Am Legend" in which the male protagonist played by Will Smith opens the cupboard, which is full of canned food, and even the kitchen countertop is filled with a variety of canned food, when many people in the barrage say: "Won't so many canned foods expire?" "Is it nutritious to eat canned food every day?"
When it comes to canned food, many people may think of words like "unhealthy", "nutritious", and "all preservatives". There are many kinds of canned foods and a wide range of ingredients involved, is it as unreliable as people generally believe? To this end, Teacher Liu Liang of the Nutrition Department of Jilin Provincial People's Hospital specially went to several supermarkets, consulted some materials, and shared with you today the things about canned food.
Common canned foods include canned fruits and vegetables, canned meat and canned eggs.
The definition of canned food in the "National Standard for Food Safety" is: canned food with fruits, vegetables, edible mushrooms, livestock and poultry meat, aquatic animals, etc. as raw materials, processed by processing, canning, sealing, heating and sterilization and other processes of commercial sterile canned food.
Commercial sterility here refers to the fact that canned food, after moderate heat sterilization, does not contain pathogenic microorganisms, nor does it contain non-pathogenic microorganisms that can multiply in them at normal temperatures. That said, the aseptic process of canned food can be used to keep it in an unopened state for a long time.
1. No need to add preservatives
Canned food products benefit from the requirements of commercial sterility when processing, and generally do not need to add preservatives.
The usual food preservatives are: benzoic acid and its sodium salts, sorbic acid and its salts, propionic acid and its salts, Dr. Liu I checked the ingredient list of several types of canned food, and indeed did not find the figure of these preservatives. In fact, some canned foods can not add any food additives at all, like a canned tuna I found, the ingredient list only has tuna and water, and it is indeed reassuring to see such an ingredient list.
But there are also concerns about the addition of nitrites to canned foods, which can have health effects on long-term consumption. In fact, nitrite as a color protector, only allowed to be added to canned meat and meat products, is the national food hygiene standards to use additives, moderate consumption will not cause harm to the body, and nitrite to inhibit microbial proliferation also has a certain effect, and salt and use when the bacteriostatic effect is enhanced.
2. Less nutrient loss
Thinking that there is no nutrition is the impression of many consumers on canned food. In fact, canned food in the process of processing only destroyed a small part of the nutrition, most of the nutrients, such as carbohydrates, proteins, fats, fat-soluble vitamins and minerals are mostly retained, a small number of poor heat resistance vitamins have been destroyed, such as water-soluble vitamin c and B vitamins.
At the temperature of daily cooking, it is difficult to avoid the loss of vitamins in ingredients. Some canned foods also add nutritional enhancers, such as vitamin C and calcium lactate to canned fruit.
3. Easy to save, easy to eat
Before opening, canned food generally has a shelf life of up to 2-3 years, and does not need to be stored in the refrigerator deliberately, but after opening, it will destroy the sterile state and need to be eaten as soon as possible. When purchasing, be sure to confirm that the outer packaging is intact and that the cap is not abnormally raised, and it is best to choose a product close to the production date.
In terms of consumption, most canned foods do not need to be processed, ready to eat, easy to carry and store, and are ideal for travel and picnics. During the epidemic period, it is inconvenient to go out to purchase ingredients, canned food can be eaten as emergency food.
So canned food is still quite reliable, but pay attention to the following points when buying and eating:
1. Most of the canned fruits have a relatively high sugar content, diabetics and crushes who want to lose weight must eat carefully.
2. Some canned livestock and poultry meat and canned aquatic meat, especially those containing a lot of broth, and the purine content is not low, patients with gout and hyperuricemia should eat carefully.
3. When purchasing canned food, we should also pay attention to food labels and nutritional composition lists, try to choose "three low" products, that is, low sugar, low salt, low fat, if you really can't meet the requirements of "three lows", master the amount of consumption, do not greedy Oh ~
Some canned foods have special cooking methods that make them delicious and delicious, which makes many friends fall in love with them. Some people are more fond of fresh ingredients, in fact, canned food with fresh ingredients is also a different flavor, whether in the hot pot, fruit cake or fruit and vegetable salad, you may see the figure of canned food. When purchasing, please pay attention to the food label and nutrition ingredient list, and hope that everyone can scientifically choose the right food for themselves.
[1] National Standard of the People's Republic of China.gb 7098-2015 National Standard for Food Safety Canned Food[s].Beijing: National Health and Family Planning Commission of the People's Republic of China, 2015.
[2] Handbook of Practical Dietitians/Edited by Cai Donglian.—Beijing: People's Medical Publishing House, 2009.12