Microwave ovens do not cook food like other appliances. In a regular oven, hot air makes both the food and its container hot, while in a microwave, the air is cool. The microwave oven emits microwaves which cause food molecules to vibrate. The resulting friction causes heat. This heat can get hot enough to kill the bacteria in foods. However, there are a few limitations.
These microwaves heat the molecules on the outside of the food. This can, in turn, heat further inside the food, but usually there are cold spots. These cold spots are uncooked or unheated food where bacteria can survive. But, there are some things you can do to prepare food safely and deliciously in a microwave.
These guidelines are important whether you are cooking raw food or reheating a meal.
It is important to become familiar with your microwave. Different ovens will take longer to cook the same food. All foods should be cooked right away after defrosting. Never partially cook food and store it for later use.
Be especially careful when heating baby formula in a microwave, as it may result in a scald to the baby's mouth or throat. Even though a bottle might not feel warm to the touch after it has been microwaved briefly, there may be hot spots within the formula.
It is important to cook food in a container that will not melt. If the container melts, harmful chemicals can leak into the food.
Use cookware made of:
Plastic wraps are commonly used to cover food while cooking in a microwave. Some wraps have chemicals that would be harmful if they leaked into the food. Precautions should be taken to make sure that the plastic wrap does not touch the food at all. Never reuse plastic wrap. Alternatively, a paper towel or a lid for a microwave-safe container might be the safest way to go.
Microwaves themselves do not destroy nutrients. However, heat can cause the nutrient level in foods to be reduced. Water can dissolve and wash away some vitamins. This is true of any type of cooking. There has been some speculation that microwaved food can be harmful to people. There is no credible experimental evidence to back up that statement.
Academy of Nutrition and Dietetics
United States Department of Agriculture
Food Safety and Inspection Service
Canadian Partnership for Consumer Food Safety Education
Cooking meat safely. Clemson University Cooperative Extension Service website. Available at: http://www.clemson.... Accessed April 10, 2013.
Cooking safely in the microwave oven. United States Department of Agriculture website. Available at: http://www.fsis.us.... Updated May 24, 2011. Accessed April 10, 2013.
Microwave cooking and nutrition. The Harvard Medical School Family Health Guide website. Available at: http://www.health..... Updated June 2008. Accessed April 10, 2013.
Microwave ovens and food safety. Health Canada website. Available at: http://www.hc-sc.gc.ca/hl-vs/iyh-vsv/prod/micro-f-a-eng.php. Published July 2005. Accessed April 10, 2013.
Microwave ovens and food safety. United States Department of Agriculture website. Available at: http://www.fsis.usda.gov/pdf/microwave_ovens_and_food_safety.pdf. Updated October 2011. Accessed April 10, 2013.
Safely preparing and reheating foods in microwave ovens. Academy of Nutrition and Dietetics website. Available at: http://www.eatrigh.... Accessed April 10, 2013.
United States Department of Agriculture and United States Department of Health and Human Services. Dietary Guidelines for Americans, 2010. 7th Edition, Washington, DC: United States Government Printing Office, December 2010.
Last reviewed April 2013 by Brian Randall, MD
Last Updated: 4/10/2013