When ordinary cling film to wraps white mushrooms, the white mushrooms in contact with the plastic wrap will turn yellow quickly, so compared with ordinary cling film, PE Mushroom Film can keep white mushrooms from yellowing in about three days, and the fresh-keeping period can reach seven days. Air permeability: fresh vegetables and fruits need to exchange oxygen, carbon dioxide and water vapor, because of proper air permeability, the preservation period of food can be prolonged.