DEAR DR. BLONZ: I want your take on the safety of nonstick cooking sprays. What is the propellant used, and how do the sprays work? I use sprays when stir-frying vegetables or roasting a chicken, counting on it to be a healthful practice, as it’s made out to be. But my science-student daughter has advised me that these products may rely on dangerous substances, and that I should switch to straight olive oil. -- L.W., Chicago
DEAR L.W.: Aerosol cooking sprays are based on vegetable oils, such as corn, soy, canola or olive oil. Also in the mix is lecithin, an ingredient from soybeans traditionally used as an emulsifier: a substance that keeps oil and water together in a mix known as an emulsion. Finally, there will either be a pump spray device or a gas propellant.
Such sprays keep food from sticking by forming a thin oil-lecithin film between the cooking surface and the food. Very small amounts of a silicone compound and some alcohol may also be present to prevent foaming and facilitate the formation of the nonstick film. While rubbing a small amount of oil on the pan can also provide nonstick properties, the coating action of cooking sprays tends to be superior, which is especially helpful during cleanup.
Because the sprays use a minimum amount of oil, little fat is contributed to the meal. A one-second application -- an amount sufficient to cover a 10-inch skillet -- will contain less than one gram of fat. Interestingly, the Nutrition Facts labels on many of these spray products have an impractical “recommended serving” of a third of a second or less. This translates to less than a half of a gram of fat per serving, allowing the company to legally label their product as “fat-free.”
The ingredients should be clearly stated, so you can opt for a product that contains no more than the basic components. There’s nothing really unsafe in most sprays, given the small amount used. If there is a safety issue with the ingredients, it would be with aerosol sprays and their compressed-gas propellants. Some use hydrocarbons such as propane or isobutane; both are highly flammable. Such sprays should only be used on cold surfaces and kept away from all flames. There are products that don’t rely on flammable hydrocarbon gas propellants.
Always shake well before using, to thoroughly mix the ingredients. An oft-ignored drawback from the use of these products is the waste contributed by the empty aerosol can. There are refillable pump sprays that limit this waste, but the high pressure of the aerosol is what helps facilitate spray performance. If you go the homemade pump-spray route, you may have to experiment with oils, staying away from unfiltered oils with particulate matter that might clog the nozzle.
Send questions to: “On Nutrition,” Ed Blonz, c/o Andrews McMeel Syndication, 1130 Walnut St., Kansas City, MO, 64106. Send email inquiries to email@example.com. Due to the volume of mail, personal replies cannot be provided.