Are some plastic wraps safer and/or more effective than others?

By Susan Brewer, Ph.D., University of Illinois,
Department of Food Science and Human Nutrition
 
 
What sort of plastic is most effective depends on the job you want it to perform. Some films are impermeable to oxygen—this is what you want for high fat foods if you want to prevent oxidation. Most are impermeable to water—this is what you want if you don’t want the food to dry out. Some are impermeable to certain wavelengths of light—this is what you want if you want to prevent color change and/or oxidation of fats and vitamins. Some have more “body” so they will help the food hold its shape while others are very moldable and easily form to the irregulars shapes of some foods.
 
Plastic films and bags in general are waterproof and will prevent dehydration. If the plastic is clear, it does not block light. Whether or not a plastic wrap blocks oxygen transmission depends on the material it’s made of. (Saranwrap®, for example has a very low oxygen transmission rate.) The label may tell you what protection a particular product provides; if not, consult the manufacturer’s website.
 
Source(s):
Susan Brewer,Ph.D. Department of Food Science and Human Nutrition, University of Illinois, Urbana-Champaign, IL