Is it unhealthy or harmful to heat food in the microwave? – The checkout


reading time 5 minutes

Does microwave radiation make food less healthy? What exactly do these microwaves do when they heat food? Is microwave radiation harmful to humans? We separate the facts from the fables with food technologist Matthijs Dekker.

In every modern kitchen, the microwave is a standard cooking tool. Do you want to heat something up quickly, or prepare fresh vegetables for the evening meal? The device works very quickly.

Dr. ir. Matthijs Dekker is a food technologist at Wageningen University. What effect do packaging or cooking processes have on food? He examines that daily. We discuss eight suggestions about the microwave oven with him. What are the myths and facts about this device?

1 – Dangerous compounds can form when heating food in a microwave oven – MYTH

“There is no evidence for that,” Dekker says clearly, “No harmful effects have been found from eating food cooked in the microwave.”

“You have to be careful what you heat your food in. A plastic container that is not suitable for the microwave can release dangerous substances such as plasticizers. It is often indicated on the container or in its instructions for use whether it is suitable for the microwave oven or not.”

Many people have a microwave oven at home. But how exactly does the device do its job? “The radiation in the microwave consists of microwaves. That’s why the device is called in English microwave oven”, explains Dekker. “These waves have a certain frequency and cause water molecules to vibrate. And as a result the temperature rises. Initially from the water molecules in the food. The rest of the food is heated by conduction between the hot and cold parts.”

2 – When you heat food, no harmful radiation is released – FACT

The microwaves are not harmful, emphasizes Dekker. “The radiation is also only temporary. When you turn off the microwave, the radiation is also gone. There is nothing left in the food.”

“The micro radiation stays inside the device, so it cannot do any harm. There is a metal housing around the microwave oven. The door is also made of metal with transparent holes. Such an enclosure is also called a Faraday cage. If you When you open the door, the the radiation source in the microwave oven immediately so that the radiation does not go outside the appliance.”

What could the radiation do if it reached beyond a microwave oven? “Man is largely made up of water, just like food,” says Dekker. “Water in humans can therefore also be heated if you stand too close and for too long. If you are exposed to microwave radiation, you get burns.”

“I don’t know if this is a monkey story, but in the US someone seems to have put their wet cat in the microwave. That animal did not survive due to the heating effect of the microwaves. Where or not: you should never dry a pet in the microwave anyway !”

3 – Eating out of the microwave four or five times a week is not healthy – MYTH

The supermarkets are full of ready meals that you only have to heat up in the microwave. And people keep leftovers, which can also be quickly reheated. Is it unhealthy to use the microwave often?

“Whether it’s healthy or not depends entirely on what you’re reheating. The microwave itself doesn’t add anything unhealthy to the food. If you only eat ready meals with too few vegetables and too much salt and saturated fat, then it’s not so healthy. But that’s not because of the device.” In short, do you want healthy food from the microwave? So warm up something healthy, says Dekker’s message.

Tip: warm through and through

The food technologist has some health advice for microwave users: Reheat the leftovers or the ready-made meal thoroughly. If it contains harmful microorganisms, such as bacteria, they will at least be killed.

“The intensity of the radiation is not the same everywhere in the microwave. Part of the food may already be very hot, while another part is still cool. At least not yet at the temperature where bacteria are killed.” So stick to the prescribed cooking time and microwave power on the package with the meal.

4 – Never put metal objects in the microwave – MYTH

According to Dekker, it is a misunderstanding that metal does not belong in a microwave oven at all. “It is best to leave a spoon in a container with food, provided it is not too close to the wall of the microwave. Only it will not work well to heat food in a metal container because the metal blocks the radiation. it only heats up through top if it’s open.”

Certain metal objects do not belong in the microwave oven. “This applies to objects with a sharp metal edge or corner or metal objects that come close to the wall of the microwave. Then you can see those sparks.”

5 – You cannot cook food with the skin on in the microwave – FACT

This statement has been approved by Dekker. “Because radiation heats water in the product, it will boil when it’s hot enough. Normally it evaporates. If that effect is prevented by a shell, you can get overpressure. Ultimately, if the shell goes in, it can lead to some sort of explosion pieces and the pressure is released all at once. Then your microwave becomes a mess…” Think of cooking an egg in the microwave. It is not unsafe, but it is inconvenient, says Dekker.

“This is also the reason why you have to poke holes in the packaging for a microwave meal. Otherwise, it can break apart. Or if you want to cook potatoes with their skins in the microwave, then it is wise to poke some holes in it.”

6 – Large pieces or small pieces are heated equally quickly in a microwave oven – MYTH

According to Dekker, it doesn’t matter how big the portions are. “The microwave radiation only penetrates a few centimeters into the product. Only the outermost few centimeters of a large piece of meat are heated. Because of the heating line, the rest eventually follows, but it takes time.”

It is more efficient to divide large pieces of meat or other foods thicker than two inches into smaller pieces or portions. “Then it heats up faster.”

7 – Heating ice or liquid water in the microwave is just as fast – MYTH

“The microwave heats the water in the food. This happens much faster with liquid water than with ice.”

The microwave oven has a special setting for defrosting food. According to Dekker, this ensures that the heating takes place gradually, because the intensity is less. “In a normal position, when defrosting a frozen product, the already thawed parts will be too hot compared to the rest. In the defrost mode, the heat is released more evenly. You can hear this because the microwave audibly stops emitting pulses in between.”

8 – When you heat food in a microwave, nutrients are lost – MYTH

“No nutrients are lost due to the radiation,” Dekkers replies to the last statement. every cooking method, including the microwave.”

But the way in which the food is prepared is in favor of the microwave oven, the scientist believes. “The faster the cooking, the better the preservation of nutrients. For example, if you cook vegetables in water on a stove, it takes longer for them to reach the right temperature and be cooked. When the cooking water is drained, many healthy substances, such as released also disappears. because of the vegetables. With microwave cooking, cooking is much faster and you usually don’t add extra water, so you don’t lose any healthy substances. In fact, it’s a very healthy way to cook food.”

Leave a Comment