Surprisingly, the microwave oven is still viewed as space-age technology in some circles. Even though they have been a standard appliance in the American home kitchen for nearly 50 years, there’s still some confusion about the benefits of microwave cooking. We want to dispel those notions.
The Basics of Microwave Technology
Microwave ovens use short-wavelength electromagnetic waves at high frequency (about 2.45 GHz) to induce water molecules to vibrate. As in stove-top heating, vibrating water molecules get hot. The more vibration, the hotter the water gets. If you put a bowl full of frozen peas into a microwave oven, the water in the peas heats up very quickly to thaw, and then steam heat the rest of the pea. Depending on the amount of power used by the microwave, it might take only a minute or two for the peas to cook perfectly.
And that’s the big secret right there! The key to microwave cooking lies entirely in determining the right amount of time and energy you need.
Is It Safe to Cook in Your Microwave?
The magnetron in a microwave oven generates microwaves — which are short wave-length electromagnetic waves measuring between 3 feet and one millimeter. A UHF TV signal is a microwave that radiates at roughly a 3-inch wavelength. In comparison, a microwave oven radiates a wavelength of 12 cm (or about 4 3/4”). A much more accurate word here might be “broadcast” because electromagnetic waves actually broadcast outward or radiate from their source like radio waves. Since they are electromagnetic, microwaves are not the same as nuclear or ionizing radiation, which has a much smaller, higher energized wavelength.
The short answer? Yes – studies show it really is safe to cook with a microwave, and doing so retains more nutrients than stovetop cooking.
Nutrients = Power, Time, and Technique
Sure, heating does break down some nutrients. However, microwaves do a better job of preserving nutrients in fruits and vegetables than cooking on a stovetop — but you have to use the correct technique. Setting the timer and expecting perfect food is a recipe for disaster. It’s better to under-cook your food first and then cook just a little longer rather than over-cook.
For example, in our microwave oven, a bowl of frozen peas might take 3 to 4 minutes to cook on High. There’s usually enough ice that it will help steam the peas, especially if you place a microwave-safe silicone lid over the bowl. Instead of setting the timer to 4 minutes, we get better nutrient retention by cooking for only 2 minutes, stirring the contents, and then cooking again for another minute, stirring again, and then letting the peas rest.
If you prepared the peas in a small saucepan with a half cup of water on your stovetop, you run the risk of boiling the nutrients away (especially if you get distracted by pets, children, or your phone.)
A Food Science Journal research paper from 2009 entitled Influence of cooking methods on antioxidant activity of vegetables evaluated 20 vegetables prepared with home cooking methods and found that for antioxidants.
“…griddling, microwave cooking, and baking alternately produce the lowest losses, while pressure-cooking and boiling lead to the greatest losses; frying occupies an intermediate position. In short, water is not the cook’s best friend when it comes to preparing vegetables.”
Let me count the ways:
- Microwaves heat and thaw foods faster than other methods. Breakfast, lunch, and dinner are all covered.
- Microwave-safe food containers let you place everything from soups to mac and cheese to popcorn inside and get a snack in only a few minutes.
- And there are plenty of recipes available to help you prepare fantastic meals in a fraction of the time you’d otherwise spend fussing over a stove.
Use Less Energy
Microwave ovens use less energy than all conventional ovens or stoves since they directly heat up the water in the food. On a stovetop, the heat transfer time from the burner to what’s in your saucepan depends on the quality and type of cookware you use.
Microwave ovens don’t retain heat, nor do they heat up everything in the kitchen and add to your summertime cooling load. By being able to directly control cooking time, you have much better control over how much power you use.
Dangers of Too Much Heat
Microwaves ovens have exposed some problems with food preparation habits in modern life. While some kinds of plastics are microwave-safe, research shows there are some important precautions to keep in mind while cooking in your microwave.
1) Beware of Type 7 “Other” plastics
Bisphenol A (BPA) is a chemical widely used to make plastics and epoxy resins. It is known to have possible health effects on the brain and prostate gland of fetuses, infants, and children. It can leach into food from the internal coatings of canned foods and from consumer products such as polycarbonate tableware, food storage containers, water bottles, and baby bottles. Don’t use polycarbonate plastic food containers in a microwave.
2) When it wears out, recycle it
Phthalates are used in the manufacture of PVC plastics (Type 3). It has a nasty habit of leaching into the products when used as packaging, such as packaging film used for food. Phthalates are endocrine disruptor compounds (EDC), and the greatest harm is linked with chronic exposure. Researchers for the International Journal for Environment Research and Public Health tested Polypropylene (PP) microwave-safe containers for leaching phthalates.
While PP does not require phthalates for manufacture, the compound is often present. It was discovered that the longer a plastic container is heated and the longer it is used, the more phthalates it releases. As plastic containers get old, they slowly develop deformities and resist heating, allowing more phthalates to leach into food. If you see wrinkles, scars, or lines in your favorite plastic food-warming container, then it’s time to recycle it.
A Great Alternative to the Stove
Don’t get us wrong – we love cooking a great meal for our family on the stove. Some meals really can’t be replicated in the microwave! What we hope to show you is that it really is OK to use your microwave to heat much of the food we eat on a regular basis. And besides the convenience of it all, cooking with a microwave regularly could also lower your monthly energy usage.