Microwave ovens have simplified life unbelievably. There’s no denying it. Like refrigerators, this unique invention is now a kitchen staple. The heat/reheat food efficiently and fast, and you can also cook dishes from scratch. In fact, there’s an entire food section in supermarkets dedicated to this marvel: microwave dinners! But if microwaves are basically radiation, is it safe to expose your food to it?
The short answer is Yes! (sigh of relief) But this comes with some qualifiers. Or as the manufacturer’s guide says: precautions. These specifically relate to exposure to microwaves, thermal burns, and food handling. For the most part, microwave ovens are safe and convenient for heating and cooking a variety of foods.
How now, microwave?
To get technical: a microwave oven basically heats your food by exposing it to electromagnetic radiation in the microwave frequency range. The electromagnetic radiation agitates molecules in the food-producing thermal energy and heating the food. In scientific lingo, this is known as dielectric heating.
So there’s still radiation? Not really. Just as the light from a lightbulb disappears when you switch it off; microwave energy disappears when the oven stops. This means food cooked in a microwave oven does not become radioactive, So go ahead and enjoy it!
Here are a few basic do’s and don’ts to help you make the most of this indispensable device.
- Never stand to close to the microwave. This means—and this is directed specifically at small children—no pressing your face against the window regardless of how fascinating you may find the sight of slowly rotating food. Keep at least a foot (30 cm) away from the oven. The further the better, since radiation decreases rapidly with distance.
- Do not over- or under-heat the food; over-heating will make the food too hot to handle/consume. Under-heating can leave food uncooked, and unhealthy to consume.
- Make sure that your microwave oven is in good condition. If it’s old or broken — or if the door doesn't close properly — repair it or consider getting a new one.
- Never microwave a plastic container unless it's specifically labeled safe to use. That’s because plastics contain hormone-disrupting compounds like BPA, which can contaminate the food when heated.
- Avoid putting metal in a microwave. When food is microwaved, the molecules heat up, water converts into steam, and energy is released. But with metals, the molecules have nowhere to go, and will eventually catch fire.
Microwave oven vs conventional cooking methods
The main difference is that microwave energy penetrates faster and deeper into the food, reducing overall cooking time. However, the rate of heating depends on the power rating of the oven, the water content, density, and amount of food being heated.
On the other hand, microwave energy does not penetrate well through thicker pieces of food. This causes uneven cooking. Which is why food in the same plate is sometimes simultaneously piping hot and ice cold. It is also a health risk if parts of the food are not heated sufficiently to kill potentially dangerous microorganisms. Because of the potential for uneven distribution of cooking, food heated in a microwave oven should rest for several minutes after cooking is completed to allow the heat to distribute throughout the food.
As long as one follows these simple precautions, food cooked in a microwave oven is as safe, and has the same nutrient value, as food cooked over a flame or in a conventional oven.