What food should be stored in the freezer of the refrigerator?

What's in the freezer of your refrigerator? What foods should be put in the freezer? I have also asked many friends this question. A friend said: The mooncakes that I didn't finish last year are frozen in my freezer ... I guess I won't throw them away until the Mid-Autumn Festival next year, and then I'll add a batch of mooncakes. Another friend said: the meat and chicken that the company sent six months ago are still frozen. Another friend said: There are many quick-frozen buns in jiaozi, and there are many ice cream, ice cream and other cold drinks. Why do you throw food into the freezer? Can the freezer really keep food forever? The so-called knowing what it is and knowing why it is, here, we will focus on the basic principle of frozen preservation and what the preservation effect of frozen food is. 1 Stop the reproduction of microorganisms, so that food will not go bad. Under freezing conditions, the biggest advantage is that microorganisms cannot grow and reproduce. Even after some pathogenic microorganisms have been frozen for a long time, the number of viable bacteria can be reduced. However, this does not mean that the microorganisms originally carried in food raw materials will completely die in the freezer, but they will no longer flourish and will not reach the quantitative level that will make food corrupt. So, not long ago, it was not surprising that people heard that frozen jiaozi contained a kind of bacteria called "Staphylococcus aureus". Just last year, there was a serious food poisoning incident in Germany, which was said to be caused by quick-frozen strawberries. This is another good proof that freezing will not completely freeze bacteria to death, and frozen food needs to be sterilized before eating to ensure safety. Because microbes don't breed in the freezer, many foods that are about to expire in the freezer can be thrown into the freezer if there is no hope of eating them for the time being, before the microbes slowly breed and lead to corruption. For example, I usually have a box of tofu in my refrigerator, and its package indicates that it can only be refrigerated for 7 days. However, I'm going to a meeting in another place tomorrow, and the tofu will expire the day after tomorrow. What should I do? The easiest way is to put it directly in the freezer. Just come back and eat frozen tofu, thaw and cut it into pieces and cook it. In addition to bean products, cooked meat, cooked fish, etc. can be frozen if they can't be eaten in a few days. Although the taste may be slightly worse after thawing, at least things will not be wasted. 2. Reduce the speed of chemical reaction and prolong the shelf life of food. In addition to the reproduction of microorganisms, there are many chemical reactions that make the quality of food worse. For example, the oxidation reaction of fat will make fatty foods taste bad, even unbearable "spicy taste" or rancid smell. For example, the color of food will change and gradually become brown and black; The texture of food will become less and less delicious during storage, and fish will become hard and firewood. At the same time, people are also worried that vitamins and health components in food will degrade during storage, and their health value will be lower and lower. In the last blog post, we said that the speed of chemical reaction will decrease with the decrease of temperature. When food is put into the freezing room at-18 degree, the speed of many chemical reactions will be obviously reduced, that is, the change of food quality will be much slower than that at room temperature. Therefore, for those low-moisture foods that can be stored at room temperature, the shelf life can be greatly prolonged in the freezer than in the freezer. For example, one day I went to a famous tea producing area and bought a lot of high-grade tea, but I couldn't finish it for half a year. If it is kept for a long time, it will lose its fragrance, so it can be divided into small packets, wrapped tightly in airtight packaging, and then put into the freezer. In this way, when you take it out the next year, the taste is as fresh as ever. In addition to tea, health care products and some precious medicinal materials, if they are not used up for a while, they are also suitable for storage in the freezer. However, for those foods with high moisture content, the effect of freezing on food preservation is closely related to freezing speed and preservation temperature. Although lowering the temperature can slow down the chemical reaction and is beneficial to preservation, freezing is not a good thing. Water is a wonderful substance. When it freezes, its specific gravity will drop from 1.00 to 0.9 1, and its volume will increase by 9%. Moreover, the phase change heat of water is extremely high, and a lot of energy is released when it freezes, so it is very difficult to reduce the temperature from 1 degree to-1 degree. After freezing, due to the sharp ice crystals, the volume will increase again, piercing the cells, leading to the outflow of cell juice, and the texture will become soft after thawing. Therefore, when freezing, it is necessary to go through the freezing process as soon as possible under the conditions of extremely low ambient temperature and efficient cold transfer, so that the water in food can not form large ice crystals, but form many tiny ice crystals to avoid puncturing cells, so that the consequences of juice loss and soft texture are not easy to occur after thawing. This is the meaning of "quick frozen food". No one wants to produce "slow frozen food" because its quality is definitely poor. At the same time, in the process of freezing, there is always some water in food that is not frozen. This is because only pure water can form real ice crystals, and food is not pure water, which contains dissolved substances. The higher the solute concentration in water, the lower its freezing point, and the less likely it is to freeze-it is a truth to sprinkle salt to melt snow when it snows. When the temperature drops below freezing point, pure water becomes ice, and the remaining solute will be concentrated, which will make the freezing point drop and stubbornly resist freezing. However, when the solutes in these waters are crowded together, various reactions are more likely to occur, and the quality of food will also decline. -Low temperature will slow down the chemical reaction, but freezing will aggravate it. Who is more powerful in these two processes? That depends on how low the temperature is. If the temperature is extremely low, as low as-18 degrees, the overall effect is to make the food more stable. If the food is stored at a few degrees below zero, the cooling effect is not great enough to offset the freezing effect. In this way, the preservation effect of food is not as good as that in a zero-degree fresh-keeping refrigerator! Therefore, it is necessary to adjust the freezing room to a low enough temperature, and it is not allowed to be overloaded and frosted too much, otherwise the refrigeration effect will decrease and the storage effect will become worse. Use the method of freezing preservation to prevent all kinds of starch foods from drying and hardening. As we all know, all kinds of cooked staple foods will dry and harden after a period of time. This is true of rice, steamed bread, noodles and cakes. This is a process called "starch retrogradation". This process will happen at room temperature, but it will happen faster at the temperature of the refrigerator, so the steamed bread cake will still harden in the refrigerator, and because the mold can withstand the cold storage temperature, it will become moldy after a long time. However, in the case of freezing, the process of aging and rejuvenation is almost impossible. It is necessary to store all kinds of cooked pasta in the freezer. For example, in the supermarket, I bought two-for-one fast-expired bread and a large package of steamed bread rolls. If I can't finish them, I can put them in a small bag and freeze them, so I'm not afraid of the expiration problem. Under freezing conditions, mold will never grow. Take it out and thaw it in the microwave oven. As always, soft and fresh! Defrosting heating time should be short rather than long, and the final heating temperature can reach room temperature. And it is best to thaw it with packaging. Because it is heated to room temperature, there is no need to worry about the decomposition of plastic bags and the release of toxic substances. The same is true of rice and steamed bread taken out of the freezer. Although there is nothing wrong with freezing moon cakes, it is a pity to put them in the refrigerator for a whole year and then throw away the old ones and put them in the new ones! It is better to give it to community workers and young and thin security guards before the holiday expires! 4 grain beans and dried fruits can be stored frozen for a period of time to prevent insects. In summer, grains, beans, nuts, dried fruits, etc. Are easy to breed insects. Especially delicious raisins and dates, often grow some nasty meat worms. If it is divided into edible small packets in advance, wrapped tightly and frozen in the freezer for two or three weeks, the eggs naturally carried in natural food will not germinate normally, and sealed agricultural products will be preserved for a longer time. Like freezers, freezers must separate raw food from cooked food, and meat from vegetables. And all the food should be packaged separately to avoid mutual pollution. Raw fish and meat in the freezer will carry a lot of bacteria, even a variety of pathogenic bacteria. Never mix them with cooked food, quick-frozen staple food and cold drinks. Having said that, we know how to store food in the freezer: 1 raw fish, raw meat, seafood and raw tofu. These raw foods that need to be fully heated can be placed on the lower floor. 2 all kinds of cooked pasta, cakes and other starchy staple foods, as well as all kinds of cold drinks, are placed on the upper floor. 3. Various self-frozen products, such as self-packaged quick-frozen steamed buns and quick-frozen jiaozi, homemade quick-frozen peas, quick-frozen Toona sinensis, quick-frozen beans, quick-frozen strawberry mulberries, etc. Put it in the middle or upper layer with quick-frozen staple food. Anyway, it must be separated from fish and seafood. Speaking of homemade quick-frozen food, I'm afraid many friends haven't tasted it yet. In fact, many new refrigerators have a "quick freezing compartment", that is, an extremely thin and flat drawer at the top of the freezer-but most families are either idle or just use it to freeze ice cubes. Fresh fruits and vegetables vary greatly from season to season, and in some seasons they are not even available at all. If you make quick-frozen fruits and vegetables at home, such as quick-frozen strawberries, quick-frozen mulberries, quick-frozen peas and quick-frozen Toona sinensis, you can keep more delicious food for your family. The method of freezing all kinds of vegetables is simple. Usually, it needs to be cleaned and trimmed in advance, blanched in boiling water, precooled in the cold room, preferably wrapped in ice clothes, and finally sealed in the freezing room for storage, which can be kept for 1-2 months. However, before quick freezing, it is necessary to make full preparations, bag, cut into flat pieces or small pieces, precool to near 0℃ in the cold room, and then freeze in the quick freezing room. Whether it's jiaozi or fruits and vegetables, whether quick-frozen grids are used or not, they must be flattened or tiled when frozen. Finally, freezers, like freezers, need to be cleaned regularly. It is recommended to clean and wipe once a month. At the same time, thaw. You can't tell the difference between raw and cooked quick-frozen grids. It is recommended to clean it every time you use it. For food with high moisture content, if it is kept in the freezer for a long time, it will not rot, but will also lead to quality degradation, especially the oxidation of fat, the deterioration of protein texture and the reduction of vitamin content. Therefore, even if the quick-frozen food can be stored for 12 months without corruption, it is best to eat it within two months. Otherwise, it's really not cost-effective to spend the fresh price, eat the food with poor nutrition and bad taste, and pay a large electricity bill! My related journal: 2013-01-kloc-0/6 | Are you using the refrigerator and freezer correctly? 2008-04-08 | What food must be put in the refrigerator 2008-04-05 | What food does not need to be put in the refrigerator 2005-08-27 |.