If it is a purchased packaging product, you need to look at the preservation matters.
1, pay attention to the brand and shelf life.
Generally speaking, no matter in cold chain transportation or production and processing, big brands are more secure in quality. Although the frozen food has a long shelf life, we should try to choose products close to the production date, and try to finish the frozen food closest to the shelf life first when eating.
2. Buy in a supermarket with perfect and reliable freezing conditions.
The nutritional value of quick-frozen food lies not in quick-freezing itself, but in cold chain preservation in sales. Generally, quick-frozen foods should not be thawed in the whole preservation process, but the cold chain in many places can not be guaranteed, which may easily lead to partial thawing of quick-frozen foods during transportation and storage, thus causing a large number of microorganisms to multiply and affecting their nutritional value and safety. Therefore, when buying frozen food, the first thing to look at is whether the freezer and refrigerator are in good condition. If there is no complete freezing condition (especially some supermarkets will turn off the power of the freezer at night), it is not recommended to buy it.
3. Choose packaged products without ice and ice crystals.
Try not to buy bulk frozen food, especially all kinds of meatballs and hot pot meatballs. Although packaged frozen food will be more expensive, it is relatively safer and healthier. Fresh and quick-frozen fish, meat, shrimp, jiaozi or vegetables should be uniform in texture, and there should be no ice and ice crystals in the package. However, if the temperature fluctuates during transportation or storage, large ice crystals and ice cubes will be formed, and the goods in the package may stick together, resulting in more and more ice crystals and ice cubes. At this time, the quality of food has obviously decreased, and the taste and flavor will be greatly reduced. Therefore, when selecting frozen food, we should also carefully check the state of the goods. If you see ice crystals and adhesion, it is recommended to buy them carefully. Be sure to eat it as soon as possible when you buy it home, and don't store it for too long.
4. When shopping in the supermarket, finally buy frozen food.
Many people put frozen food into the shopping basket as soon as they arrive at the supermarket, and then shop for 1~2 hours before checking out. As we all know, the temperature in the supermarket is not low. From the time the frozen food leaves the freezer to the time you go home and put it in the refrigerator, bacteria have been multiplying in the frozen food for several hours. Therefore, when visiting the supermarket, it is recommended to buy frozen food at last. If you don't want to eat it immediately after you buy it, you should put it in the freezer immediately.
Second, several common thawing methods
Air thawing method
Take the frozen food out of the freezer and put it in the freezer. Usually eat it at night and eat it the next morning. Or take the frozen food out of the freezer and thaw it directly in the indoor air. Remember that food should not be left in the air for a long time, otherwise it will easily lead to food spoilage.
Running water thawing method
When frozen food is in urgent need of eating, running water thawing method can be used. Because the heat transfer performance of water is better than that of air, the thawing time can be shortened. However, it should be noted that frozen food should not be in direct contact with water, and should be packaged in sealed packages, such as sealed boxes and sealed food bags, otherwise the nutritional components of food will be washed away by running water, which will make the taste of food worse. Remember: frozen raw food should not be thawed completely, only to the extent that it can be cut with a knife, not too much. Such as meat, fish and other foods, if completely thawed, there will be a lot of blood flowing out.
Heating thawing method
After the cooked cooked products are frozen, the heating thawing method can be used for thawing. However, when thawing, attention should be paid to adding a small amount of water and slowly heating it with a small fire to prevent the phenomenon of external rot and internal cold from thawing in a big fire.
Microwave oven thawing method
Microwave ovens use electromagnetic waves to make polar molecules in frozen food rotate at a very high speed, and use the principle of mutual vibration, friction and collision between molecules to generate a lot of heat energy, which makes frozen food heat from the inside out at the same time and shortens the thawing time.
Salt water and vinegar thawing method
If it is too late to put it in the refrigerator, you can thaw the meat completely with salt water. This is because salt water can accelerate the melting of ice without breeding bacteria. Tap water is not suitable for thawing meat. In addition, you can also dip vinegar in the meat with a fork, which can also speed up the thawing.
Three, all kinds of frozen food thawing matters needing attention
fish
Should be thawed in 4%~5% salt water at 40℃~50℃. Because under this condition, the muscle tissue of fish has the strongest toughness and the best taste.
Edible meat
It should be thawed at room temperature 15℃~20℃, and it is best not to thaw in water to avoid loss of nutrients.
egg
Can be placed in a watertight metal container, which can be quickly thawed by soaking in water at 20℃.
poultry
Generally, it can be thawed in water, but it should be thawed naturally at room temperature to avoid odor.
vegetables
Frozen vegetables cannot be scalded with boiling water, nor can they be naturally thawed at room temperature. Vegetables are perishable and nutrients are easily lost. Therefore, frozen vegetables do not need to be thawed, and can be cooked directly after cleaning.