12 myths and truths of the microwave – 03/12/2019

The microwave is now present in most homes, but still raises suspicions. From time to time, information appears in the networks, stating that everything is happening in the water, blows eggs or emits harmful radiation. Some are true and others are real barbarities. "To a certain extent, it is normal that doubts arise, because the microwave is a closed and opaque box that cooks without following the traditional method, and that always creates a plot," said Laia Badal, Fundació Alícia, expert in a home appliance born After the investigations to create a radar during the second world war.

In 1945, the engineer Percy Spencer was testing a new vacuum tube called magnetron when he discovered that a candy in his pocket had melted. Thus, accidentally, he knew that the microwave that generates this device rotates the water molecules of food, which are thus heated.

Microwave ovens began to be manufactured in the 1950s, but it was in the 1970s that they were introduced into American homes and by the end of the 1980s they were already present in 25% of households. Today, he is considered a popular, fast and efficient method cooking, but still a big unknown. We are discussing with Fundació Alícia, a research center on technological innovations in cooking and eating habits, to scientifically solve the doubts and myths that still surround this almost octogenarian device.

Waves make cooking food dangerous

FALSE

It is absolutely false that food cooked or heated in the microwave is dangerous. Microwaves are high frequency electromagnetic waves, similar to a cell phone, cable TV or radio, which act on certain molecules (the polar) of water, fats and sugars without altering them. "In any case, it does not change the chemical composition of the food, beyond the usual changes of a cooking method," says the chemistry of Fundació Alícia, which since 2011 carries out research on the microwave and cooking.

The scientific explanation of the operation of the device seems complex but simple: water molecules are a good example of polar molecules, ie they have a end with a positive charge and the other with a negative charge. The electromagnetic field interacts with them like a magnet and moves them causing shocks with other molecules. In this way, heat is generated and the water boils. That molecules move is something harmlessthis poses no problem, it is wrong that the waves destroy molecules, they explain.

The continuation of the use of the sick device

FALSE

There was a time when the microwave was so unknown that it was even thought that it could poison, leave helpless or blind to anyone who used it. Today, no one believes it, but the idea of ​​staying in front of their job when they work can still cause cancer. Claudi Mans i Teixidó, professor in the Department of Chemical Engineering of the University of Barcelona, ​​explains that the waves of the device do not emit ionizing radiationthat is to say that do not cause mutations in living beings, do not affect the DNA nor increase the risk of developing tumors.

In 2005, the World Health Organization (WHO) issued a document stating that, if used in accordance with the manufacturer's instructions, the microwave is safe and convenient for heating and preparing food for for consumption. It sounds incredible, but on the Internet, it says in instruction manuals in the US that one should not introduce animals (like cats or dogs) to dry them, and if that 's the case, it' s probably because someone invented this madness and introduced it. a request to the manufacturer. "We do not know if this has actually happened, but in any case, it's outrageous because it burns the organs and blood of the poor animal," Laia Badal explains.

The microwave can burn you

TRUE

Unlike cell phones or radar, in the microwave oven, the waves are concentrated in a closed space. "The risk we run is that they go outside, because they could cause us the same thing as food, heat our fabrics and burn us," says Badal. She stresses, however, that the importance of the device is in perfect condition. We must check that the door closes properly and that it does not show any fracture, for example, caused by a knife falling over the oven. "Microwaves have security systems to prevent the waves from getting through the metal walls of the device," he said. The walls have a wire mesh with 1.5 mm holes and the microwave wave length is 12 cm, so you can not cross it.

We can also burn our hands using the microwave in another way: if we remove a very hot container. According to the WHO, it is one of the major risks of the device. "To avoid this, it is important to know the operation of the oven and to control the cooking times of each dish," says the expert, who also recommends the use of mittens.

We can check if a microwave is leaking by calling a phone inside

FALSE

It is said that to check if a microwave has radiation leaks, you can put a phone inside, shut down the device (without turning it on!) And if the phone rings, it leaking. If this does not sound, the oven closes tightly. It's a myth because the cell phone always rings, whether the device is running or not, because the microwave and phone waves are close but different. "So, the waves of the phone can go beyond the protection of the door and it will be heard, though more attenuated, "said Professor Claudi Mans i Teixidó." It's the same thing that happens if you put your cell phone in a pressure cooker covered, "he says. .

Microwave destroys all nutrients

FALSE

"Foods cooked in the microwave are as safe and have the same nutritional value as those cooked in the oven or in a traditional kitchen," says expert Alícia Foundation. This does not mean that nutrients are not lost: "Some vitamins and minerals are lost, as happens in all kitchens".

In this sense, the microwave has the advantage that the temperature is not very high and that the energy penetrates deeper into the food and therefore reduces the cooking time. One of the worst techniques in nutrient loss is to boil because it is cooked in water and the water soluble vitamins are lost. In order to fully preserve the qualities of food, it is advisable to eat them raw.

You can not cook all kinds of food

FALSE

In the microwave, you can cook everything by following the appropriate instructions. However, we must be aware that it has certain limitations, for example, the inability to offer the famous Maillard reaction whereby the bread and meat appear golden and have a toasty tip. It happens because the device does not reach very high temperatures. "It can be a problem because we are used to it culturally and it may seem like it has not done well," says Badal. It is important not to exceed the recommended cooking times in order not to overcook foods and to use appropriate containers. Another little-known feature of the microwave is that cooking depends on the composition of the food, as we will see in the next point.

The one in the microwave is uneven cooking

TRUE

It is not true that the waves cook food from the inside, but that the cooking depends on the composition of the food. The way they heat has nothing to do with conventional cooking. "If we fry sardines in a saucepan, the heat reaches the whole fish evenly because it is in contact with the fire, but in the microwave, the energy can act faster in certain areas of the kitchen." Food according to its composition, "explains Badal.

Products or food zones containing less water or other components containing polar molecules (such as oil) cook more slowly because the waves can not move their molecules so easily. They are quite easy to cook fish and vegetables but with some products it is impossible. For example, "solid sugar does not contain these molecules, so if we do not moisten it, the oven does not detect it and does not turn it into candy," says the expert.

This type of heating is not uniform by definition, but you do not have to suffer because the product is not well cooked. From the Alicia Foundation, point out that the oven 's turntable allows the waves to spread everywhere and recommends brewing the dishes (eg, macaroni) to balance the temperature and close the containers to concentrate the steam to the oven. interior and make cooking easier "but not this must be done tightly because they would explode. "

There is a difference between cooking and heating food

TRUE

In a microwave oven, we can cook dishes and defrost or reheat already cooked dishes, but again, the way waves are transmitted is fundamental to understanding each process. "The cooking is optimal because the raw product is always the one that contains the most water", says the expert, who recommends adding vegetables to a few tablespoons of water and let the fish rest a minute after getting out of the oven to finish cooking with the heat residual.

If the same food is already cooked at noon and we want to heat the leftovers at night, the process is the same but "the cooking will take longer because it will be drier".

It's an easy system for thawing food

TRUE

Defrosting a food in the microwave is very common, but one may be surprised to discover that the process is not homogeneous. It should not be forgotten that freezing paralyzes the movement of the molecules of the product, thus its rate of absorption of microwaves. "It can begin to defrost at one point and develop gradually.This process is not very optimal, but it is fast and runs on a daily basis," emphasizes the chemistry of Fundació Alícia. To achieve greater homogenization, Badal recommends always using the lowest defrosting power (and avoid overloading the more watery areas), placing frozen foods in a covered container and coat with a little oil.

The water: it springs, its DNA is altered and it kills the plants

TRUE AND FALSE

Sometimes we heat water in the microwave (for example, to prepare an infusion) and, after removing the glbad from the oven, we find that it begins to boil violently when the sachet is introduced. tea, sugar or a simple teaspoon. It can explode or seem to explode, but calm because there is nothing harmful in this phenomenon, which has a scientific explanation. It is the so-called boiling.

According to the WHO, in traditional cooking (in contact with fire or a plate), water vapor escapes by the action of bubbles when the water comes out. water begins to boil. In a microwave oven, however, the water is heated with energy from all over and can reach 100 ° without producing the typical bubbles. Suddenly, it can start boiling when we introduce an object, because we generate an air bubble inside it and do it in a way that seems to explode. The only problem with this physical phenomenon is that it can cause burns, alert the WHO.

Regarding the second point, whether the microwave changes the water's DNA, it is absolutely ridiculous because the water does not contain DNA and if it does had, the microwave would not affect because the composition of the food does not change. It is also absurd to believe that plants irrigated with water heated (then cooled) in a microwave oven die in the short term.

The egg explodes and the chocolate burns

TRUE

It is not advisable to introduce a whole egg in the microwave. The energy can cross the shell and heat the inside of the egg very quickly as it contains fat. Since there is no possibility that steam escapes, the egg may explode inside or outside the oven as you pierce it. Badal recommends using specific utensils to cook the egg, taking into account that it cooks very quickly: "The egg gives very good results if you throw it on a vegetable already practically cooked to give it a tasty touch and you cook it for a few more minutes. If you want to melt chocolate in the microwave, you have to be careful because it burns easily. "It has little water, sIt heats a lot and requires a lot of control. You must do it with little temperature. Every 30 seconds, you have to remove it and remove it to avoid burns ", explains the chemist, who recommends adding milk to facilitate optimal cooking According to the chef Eva Arguiñano," if you accidentally pbad the point optimal, you can recover the chocolate by adding chocolate chips and mixing them until they are melted ".

Any container is valid for a microwave

FALSE

You can only enter those that are approved and manufactured to withstand high temperatures. It is said that plastics and microwaves are incompatible with this oven because heat can cause the migration of components or negative substances from plastic to food ", but we already find on the market many plastic containers that we use to transport food at work perfectly fit to cook in the microwave, "says the expert from Fundació Alícia.

Also, it is not recommended to cover the plastic film containers to better retain moisture, unless otherwise indicated on the label. Among the materials that work well are the silicone and pírex, a material that the expert considers more advisable than glbad because it is more resistant. Metals do not match these ovens because microwaves move their electrons, they can accumulate at one end or on the surface and even cause sparks. "They work like an antenna, change the orientation of the waves and focus them in many cases to the magnetron, which can burn it," says Badal, who considers aluminum to be particularly dangerous. We must remember that we can not in any case try to dry a cell phone in the microwave because it would cause an explosion.

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