The packaging of plastic wrap will be marked with material. If there is only Chinese name on the packaging, you should also pay attention to different materials, but there are many differences! Comparing the two, purchasing PE material will be safer than PVC material.
Material: PE (polyethylene) heat resistance (Celsius): - 60 ~ 110 degree viscosity: poor waste treatment: non toxic after combustion
Material: PVC heat resistance (centigrade): - 60 ~ 130 degree viscosity: good waste treatment: toxic after combustion
It's more comfortable to use plastic wrap like this! Use a deeper container
Da Ren suggested that the fresh-keeping film of any material should be at least two centimeters away from the food. Put the food materials in a deep bowl or glass box, so that the fresh-keeping film can only be used in contact with the container, rather than the food itself.
Let the food cool first
No matter which kind of fresh-keeping film is made, as long as the temperature of "direct contact" is higher than 60 ℃, the fresh-keeping film will easily melt plasticizer or toxin, and then eat toxic substances. If the hot food is placed in a deep bowl, the food should be cooled first, and then covered with the fresh-keeping film on the container, so as to avoid the contact with the fresh-keeping film after the hot air rises, and release toxic substances.
Although PE and PVC fresh-keeping film can cover fresh vegetables and fruits without grease and normal temperature after washing, it is recommended to thoroughly clean the fruits and vegetables with fresh-keeping film bought from the store. If you want to keep food fresh in the way of cold storage and freezing, first use paper towel or white paper to isolate fruits and vegetables, and then use fresh-keeping film on the outer layer to keep fresh, which is the safest use principle!
Avoid high fat food
Experiments have proved that one kilogram of "high fat" Gish coated with PVC fresh-keeping film at room temperature will dissolve 81-104 mg of DEHP after one hour. Adults should not ingest more than 0.02 mg of DEHP per kilogram. If they eat 200 grams of contaminated food in one day, they will. Therefore, it is suggested that high fat foods such as cheese, ham, sausage, etc. should not be directly contacted with the preservative film.
Absolutely no heating although the heat-resistant temperature of PVC and PE film is at least 110 ℃, as long as they are put into the electric rice cooker, oven or microwave oven for heating, it is easy to make the film soft or deformed, and then release the chemical substances. For a ten person electric rice cooker, the maximum temperature can reach 140-165 ℃, which is more than the heat resistance of the plastic film, and it is quite dangerous. It is not recommended to use electric rice cooker for heat preservation.
Q & A
Can plastic wrap really keep 100% fresh?
The air tightness of the fresh-keeping film is not good, so it is not necessarily fresh-keeping, but it can moderately block the air and avoid food oxidation. It is suggested to use a fresh-keeping box or glass box with good air tightness, which can also block the food from being put for a long time and the refrigerator has smell, and the fresh-keeping effect is better.
Is the "silica gel" wrap on the market safer?
The heat resistance of silica gel film is high (40-230 ℃), which can be cleaned and reused. It can also be directly used in microwave ovens and ovens. However, the disadvantages are high price (about 200 pieces of 20x20 cm) and fixed size. The size of the containers that can be used is limited. To reach the heat resistance limit, silica gel film will release potential chemicals. In addition, it should be carefully selected. Material and source: pure silica gel can have the effect claimed above.
How to distinguish the fresh-keeping film covered by fresh food in the store?
In order to save cost and consider convenience, many stores will directly cover food with PVC preservative film containing plasticizer, but the package will not be marked. At this time, you can check the outer packaging. If you use adhesive tape to stick the cling film, it means that the viscosity of the cling film is low. Most of them are made of PE material, so you can buy it at ease. In addition, you can also knead the fresh-keeping film by hand, PVC material has strong viscosity, and it is easy to stick together by hand kneading.
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