The first prototypes of microwave ovens were used to heat food during the Second World War. At that time, Rayton, a small electronics company near Boston (USA), mass-produced magnetrons (vacuum tubes necessary for new radars), which produced high-frequency oscillations. Percy Spencer, from the company's research arm, accidentally discovered that microwaves generated by their magnetrons could heat food. While standing next to a radar microwave generator in 1945, a piece of caramel melted in his pocket. This led him to investigate how microwaves affect other foods. In 1947, Spencer brought the first microwave oven to the market. It was a bulky device, as tall as a man and far from today's small ovens that are produced all over the world. In recent decades, these ovens have been greatly improved. Today, they are more aesthetically pleasing, and the price is affordable for many customers.
They have been mass-produced and sold for more than twenty years, with more than 50 million of them in use in many countries. These ovens are found in countless restaurants and corporate kitchens in many countries. In the US alone, about a million microwaves are sold annually. Since many households include microwave ovens, it's necessary to become more familiar with their good and bad qualities.
What Interests Consumers When Buying a Microwave Oven?
Most consumers don't think long before deciding to get a microwave oven. Many people don't bother to find out more about it, but are satisfied with information from advertisements, or from those who already have them. Others accept the opinion of the seller, who will again say it’s the best. Thus, only a small number of buyers know what they are getting into with this purchase. Better informed and critical consumers ask the following questions:
Anyone who wants to buy this oven for their household, restaurant or company kitchen should get to know both the positive and negative sides of its use. Only after that should they decide whether to buy it or not. Manufacturers emphasize the speed of preparing meals and saving electricity, but savings are achieved only when it comes to small portions. Contrary to the classic way of preparing food, the energy consumption of microwave ovens increases when a larger amount of food needs to be prepared.
How Microwaves Work When It Comes to Food
Microwaves are electromagnetic waves with a frequency of 10-8 to 10-12 Hz (one hundred million to ten billion oscillations per second). They occupy the range between radio waves and infrared light. Only recently has it been discovered how food is heated in a microwave oven. In ordinary ovens, the heating goes from the outside to the inside.
First, the air molecules are heated, which act on the molecules on the surface of the food, and those on the molecules in the deeper layers of the food, until after a certain time even the deepest layers are heated enough. Microwaves directly affect the food which heats up, while the oven itself remains cold. Unlike conventional ovens, microwave ovens heat both the outer and deeper layers of food at the same time, although not completely evenly in some cases.
Microwaves act simultaneously on many molecules in various layers of food. They cause movement, or the rotation of molecules, such as water, proteins, and fats. They have a particularly strong effect on water molecules, which begin to move and collide. In doing so, heat is generated, which heats other molecules such as proteins, fats and carbohydrates. That's why many people have a misconception that microwaves heat food in the oven from the inside out. Since part of the heat from the warm food is released into the surrounding cooler environment (because the oven itself is not heated), the outer layers of the food cool down faster than the deeper ones. In this way, one gets the impression that microwaves heat more deeply than those that are closer to the surface of the dish. Preparing food in the microwave oven helps to save up to 60% in time, which means a lot for employees and those who don't want to spend too much time in the kitchen.
The Downsides Of Heating Food In a Microwave Oven
Consumers often make mistakes when it comes to microwave ovens. When the food is taken out of it, it may be colder on the outside than on the inside. In a dish that has a different composition (for example, it contains vegetables, meat and dough), water molecules move and collide under the influence of microwaves. Because of this, warmer and cooler zones are created in the dish itself. In order to heat the dish evenly, it is necessary for the heat to penetrate evenly into all layers.
Experts recommend that the dish be heated a few minutes longer, that it rests for a while before consumption and that it's stirred vigorously to even out the temperature. In the instruction manuals of microwaves, they warn that the food heated continues to boil even when removed from the oven. It’s important to allow the food to cool down before eating to avoid any burns.
Dr. Ian James found that a cup of water boiled in a microwave oven cooled to 130 degrees nine minutes longer than one boiled conventionally. Since the high temperature of food heated in a microwave oven stays heated for a long time, burns can be more severe. It's known that macrobiotics reject the preparation of food with microwaves as a procedure that isn't natural and doesn't contribute to the health of those who eat such food.
Changes In the Nutritional Value Of Food Heated In a Microwave Oven
In one study, the Institute of Health came to the conclusion that the changes in nutritional value that occur in food in a microwave oven are similar to those in the classical way of preparing food. However, this claim doesn't say much to most consumers. Many do not know that during the usual ways of heating food (cooking, baking, etc.), very useful enzymes and vitamins are destroyed, proteins and biologically active substances found in raw food are destroyed, fats are changed, and so on. This is why heated food is less valuable than raw food. Whether microwaves destroy many compounds in food (which are necessary for our body) more than the usual ways of heating food, is a question that is not easy to answer. However, the changes in food heated by microwaves are similar to those that occur in the traditional way of preparing food, so these small differences aren’t significant.
On the other hand, vegetable dishes prepared in a microwave oven do lose a certain percentage of antioxidant substances, but it may depend on the vegetable and its content. Portuguese scientists have proven that broccoli cooked in a little water in a microwave oven loses up to 97% of those substances, which is why it was declared the best fighter against malignant diseases. Boiled in the usual way, broccoli loses only about 11% of antioxidants, so it is recommended to cook it with little water and for a very short time. For other vegetables, this is not the case, so it’s recommended that you research this when cookingyour vegetables. So far, it has been proven that microwaves destroy the outer cell membrane of plants, so a larger amount of water is released than during other food preparation procedures.
It's good to know that there are some differences between heating food traditionally and using a microwave oven, but the nutrients stay pretty much the same and there's no danger for their user. The radiation generated by microwaves is non-ionizing, which means that it does not have enough energy to ionize atoms or molecules in the food. Therefore, it cannot cause any harmful effects such as cancer or genetic mutations. As long as the microwave is used correctly, there is no need to worry about any negative effects on food or health. If you’re interested in browsing through our vast array of top-quality microwave ovens, visit us at Townappliance.com
