Four seas net: speaking of fresh film I believe that many people are very familiar with it. People in daily life have been very dependent on the role of preservative film, whether it is vegetables, fruits, or leftovers, as long as it is covered, the heart will be a lot more stable. I feel that the preservation of food is effectively guaranteed. But in fact, the use of preservative film is also taboo. Let's see the correct use of preservative film.
In terms of fresh-keeping film, the degree of cold and hot dishes, covered or not covered with fresh-keeping film have different effects on the nutrient content.
First of all, hot dishes have not completely cooled down. If the fresh-keeping film is covered, it will not protect the vitamin C in the vegetables, but will increase the loss of vitamin C. It should be stored in the refrigerator after the dishes cool down.
Secondly, in the process of dish storage, it should be covered with fresh film to protect vitamin C. According to the determination of experts, if the storage is calculated as per 6 hours, the preserved vitamin C is equivalent to eating an extra pear. In addition, different dishes covered with fresh-keeping film have different protective effects on vitamin C. In the same way, with 100 grams of dishes, the leek with the fresh-keeping film is 1.33 mg more than that without the film, and the lettuce leaves are 1.92 mg more. After 24 hours of storage, the vitamin C of the leek with the film is 1.5 mg less than that without the film, the radish is 3.4 mg less, and the cucumber is 3.8 mg less!
Of course, vitamin C is just one of the nutrients needed by the human body, the results of this study can not be extended to other, but at least one problem: the preservative film is exquisite.
Purchase of fresh keeping film
When purchasing, we must choose the film or bag according to the actual use. When purchasing, you should carefully look at the marks on the package. In addition, polyethylene film is generally poor in viscosity and transparency, which is easy to open after rubbing by hand, while PVC film is better in transparency and viscosity, which is not easy to open after rubbing by hand, and easy to stick on the hand; after being ignited by fire, the flame is yellow, and will not go out when leaving the fire source, with oil dripping, and no pungent smell.
The qualified fresh-keeping bag is milky white, translucent or colorless, transparent, flexible, with a sense of lubrication when touching, and the surface seems to have wax. The toxic fresh-keeping bag is turbid in color and has a drum feel. Hold one end of the bag by hand and shake it hard. If the sound is crisp, it is non-toxic. If the sound is dull, the quality is poor.