Lead: Since the development of cold chain logistics, people have begun to have stricter requirements and control on food preservation and preservation materials. In the past, people simply demanded that food should not go bad, but now people's requirement for food preservation is to ensure that the water and nutritional value of food will not be lost. Of course, when we get food, we should consider other factors besides enjoying its deliciousness, just like what we are going to talk about today, whether the plastic wrap will cause harm when it is heated in the microwave oven.

Types and characteristics of plastic wrap

According to the material and processing technology of plastic wrap, plastic wrap can be divided into polyethylene (PE) self-adhesive plastic wrap, polyvinyl chloride (PVC) self-adhesive plastic wrap, polyvinylidene chloride (PVDC) self-adhesive plastic wrap and multi-layer self-adhesive plastic wrap. It is understood that among the three kinds of cling films, PE and PVDC cling films are safe to human body. Most of the cling films currently on the market use PE as the raw material, while PVC cling films can also be used for food packaging. However, after being heated in the microwave oven, the packaging will be overheated or encounter oily food, which will produce harmful substances. The new standard stipulates that PVC plastic wrap should be marked with warning language such as "Do not touch greasy food", "Do not heat in microwave oven" and "Do not use at high temperature". Other types of plastic wrap, if claimed to be used for microwave heating, should indicate "microwave-usable", heating method and maximum temperature resistance. In addition, the plastic wrap should also be marked with the words "food use".

Is the plastic wrap heated in the microwave oven?

There are special plastic wrap for microwave ovens in the market, which can be used for both refrigerator preservation and microwave ovens. This kind of plastic wrap is far superior to ordinary plastic wrap in heat resistance and non-toxicity. However, at present, most of the plastic wrap sold in the market is vague in safety, and the materials and types are mixed, so it is often difficult for ordinary consumers to identify whether it is safe or not, which greatly discounts the safety of plastic wrap. Experts suggest that plastic wrap should not be put into the microwave oven.

Harm of plastic wrap exposed to heat;

(1) Plasticizer oozing. Unsafe plastic wrap contains a plasticizer, which can increase the adhesion of plastic wrap, but it will penetrate into food, especially high-fat food, endangering human health. When heated in a microwave oven, the exudation of this harmful substance will be obviously aggravated.

(2) Chemical reactions produce toxins. If the plastic wrap wrapped on cooked food comes into contact with the grease on the surface of cooked food or is heated in a microwave oven, the plasticizer in the plastic wrap will react chemically with the food, and the toxin will volatilize, penetrate into the food or remain on the surface of the food, thus affecting and endangering human health.

(3) The harm of plasticizer. In addition to the above hazards, plasticizers can also disturb the hormone metabolism of human body, induce congenital defects, oligospermia, breast cancer, and even lead to mental disorders.

Matters needing attention in using microwave oven plastic wrap

1, when heating oily food, the plastic wrap should be kept in isolation from the food, and the two should not be in direct contact. Because when the food is heated, the food oil may reach a very high temperature, so that the plastic wrap is damaged and sticks to the food.

2. When heating food, cover the container with plastic wrap, and then stick a few small holes in the plastic wrap with needles such as toothpicks to facilitate the evaporation of water and prevent the plastic wrap from bursting due to gas expansion.

3. The maximum heat-resistant temperature marked by different brands of plastic wrap is different, and some of them are about 10℃. When the temperature in the microwave oven is high, it will generally reach about 1 10℃. When it needs to be heated for a long time, you can pay attention to choosing plastic wrap with higher heat resistance.

What foods can't be covered with plastic wrap?

The experiment showed that100g of leek wrapped with plastic wrap had more vitamin C content after 24 hours than that without plastic wrap1.33mg, and rape and lettuce leaves had more1.92mg.. However, the experimental results of some vegetables are quite different. 100 grams of radish wrapped in plastic wrap decreased its vitamin C content by 3.4 mg and beans by 3.8 mg after storage for one day. After cucumber was stored for one day and one night, its vitamin C loss was equivalent to five apples. Cooked food, hot food, oily food, especially meat, it is best not to be packaged and stored with plastic wrap. Experts pointed out that after these foods come into contact with plastic wrap, it is easy to volatilize the chemical components contained in their materials and dissolve them into food, which is not good for health.

Conclusion: After reading Xiaobian's story, have you made a clear judgment on whether to take off the plastic wrap before heating the food in the microwave oven? First of all, plastic wrap can really play a certain role in preservation, but some poor quality plastic wrap will dissolve harmful substances in food after direct contact with food, which will not only make nutrients lose, but also harm our health. Therefore, all of us should use plastic wrap as little as possible in peacetime, and we should not buy too much food and eat it in time. Doing so is not only economical but also environmentally friendly.