Which foods should not be covered with plastic wrap?

　　Fruits and vegetables with high water content are more suitable for plastic wrap, such as apples, pears, tomatoes, rapeseed, leeks, etc., which can not only keep them fresh for a long time, but also increase some nutrients in them.

　　Experiments have shown that the vitamin C content of 100 grams of leeks wrapped in plastic wrap after 24 hours is 1.33 mg higher than that of unwrapped leaves, and the content of rapeseed and lettuce leaves is 1.92 mg higher. However, the experimental results of some vegetables are quite different. After 100 grams of radish wrapped in plastic wrap was stored for one day, its vitamin C content decreased by 3.4 mg, and beans decreased by 3.8 mg. After cucumber was stored for one day and one night, its vitamin C loss was equivalent to 5 apples.

　　It is best not to store cooked food, hot food, and fatty food, especially meat, in plastic wrap. Experts point out that when these foods come into contact with plastic wrap, it is easy for the chemical components contained in the materials to volatilize and dissolve into the food, which is harmful to the food. healthy unfavorable. Most plastic wraps currently sold on the market, like commonly used plastic bags, are made of ethylene masterbatch. Some cling film materials are polyethylene (PE for short), which does not contain plasticizers and is relatively safe to use; some materials are polyvinyl chloride (PVC for short), which often add stabilizers, lubricants, auxiliary processing agents and other raw materials, which are harmful to the human body. Therefore, you must be careful in your choice.

　　Today, there are many food packaging products on the market, such as plastic wrap, plastic bags, plastic boxes, etc. Dong Jinshi pointed out: “Preservation is mainly about water retention, quality preservation and nutrition protection. In this regard, plastic wrap has the best effect. Qualified plastic wrap has strong air permeability, allows internal and external oxygen exchange, effectively prevents the reproduction of anaerobic bacteria, and can ensure the freshness of food within a certain period of time. ”But for food such as steamed buns and snacks, it is obviously very inconvenient to use plastic wrap. In comparison, plastic wrap is thicker and not very breathable, so it is relatively suitable, but try not to seal the mouth when using it. The main function of the crisper is to seal, which can effectively isolate and store raw and cooked food, making the refrigerator space more efficient.