Use microwave radiation in food

Bocholt / Salzgitter (dpa / tmn) - Just in the freezer, a few minutes later ready to eat on the dining table - the microwave makes it possible. Frozen food is thawed or a meal prepared the day before is warmed up within a very short time.

This is ensured by the microwave radiation inside the device with a frequency of 2.45 gigahertz. Sounds dangerous, but it's not. "Food from the microwave is harmless to health," says Margret Morlo from the Association for Nutrition and Dietetics (VFED) in Bocholt. Ina Stelljes from the Federal Office for Radiation Protection (BfS) in Salzgitter makes a similar statement.

In theory, you can take food or drinks from the microwave every day. However, anyone who thinks they can freeze freshly prepared vegetables in portions and then consume a food with lots of vitamins after they have been heated up in the microwave is wrong: "Most vitamins are sensitive to heat," says Morlo. According to her, temperature, light and oxygen reduce the vitamin content in food and ready-made meals. The maximum vitamin losses vary between 40 and 80 percent. Folate and vitamin C can even be completely lost.

"If you often heat or cook your meals in the microwave, you should also eat raw fruit and vegetables every day to optimize the vitamin content," advises Morlo.

In every microwave there is a so-called magnetron, as Morlo explains. This transmitter generates electromagnetic waves. They are directed into the interior of the device, reflected by the walls of the cooking space and distributed as evenly as possible in the housing. "The electromagnetic waves mainly stimulate the water molecules in the food to vibrate strongly," explains Morlo. Because of these vibrations, heat is generated. Food with a high liquid content therefore heats up faster than dry ones.

When heating food in the microwave, the choice of dishes is important. "Microwave dishes made in-house are of course best, but porcelain and glass are also possible," says Annabel Oelmann, CEO of the Bremen Consumer Center. Under no circumstances should kitchen utensils made of melamine resin be used for frying, cooking or heating in the microwave, as Prof. Andreas Hensel says. He is President of the Federal Institute for Risk Assessment (BfR). The reason: If these kitchen utensils are exposed to the high temperatures in the microwave, higher amounts of melamine and formaldehyde can be released and migrate into food and drinks. This can be harmful to your health.

Oelmann points out that foods are often heated unevenly in the microwave. "As a result, cocoa, for example, feels lukewarm at the beginning and can burn your mouth the next moment," she explains. It is therefore important: stir first, then drink. So that food and drinks do not splash or dry out on the surface, they should be protected with a cover. Consumers should always leave food in the appliance for a few minutes after the heating or cooking time has expired. "This is the best way to distribute the heat in the food," recommends Morlo.

"Protective devices ensure that very little radiation gets to the outside during operation," emphasizes Stelljes. Nevertheless, according to your information, a small amount of so-called leakage radiation can occur in the vicinity of the screen and the doors. A limit value is specified for this in safety standards - it is five milliwatts per square centimeter at a distance of five centimeters from the surface of the device.

Measurements by the BfS have shown in the past that the vast majority of microwave devices are within the limit value. "With technically flawless devices there is no health risk, not even for particularly vulnerable people such as pregnant women or small children," says Stelljes. In principle, however, unnecessary exposure to high-frequency fields should be avoided. The BfS therefore recommends that children in particular should not stand in front of or next to the device while the food is being prepared.