Principle of operation
How does a microwave oven work?
The microwave oven contains a high- frequency tube called a magnetron. It converts electrical energy into electromagnetic waves called microwaves. These microwaves are then distributed evenly throughout the oven interior and reflected by its metal walls, which allows the microwaves to reach the food from all sides. Distribution of the microwaves is optimized by an activated turntable.
In order for microwaves to reach the food, they must be able to penetrate the cooking container being used.
Microwaves can penetrate porcelain, glass, cardboard and plastics, but not metal. Therefore, you should not use containers which are either made of metal or contain it in any form, such as gold or silver trim. The metal reflects the microwaves, which may cause sparking to occur. The microwaves cannot be absorbed.
The microwaves will pass through any suitable cookware and find their way directly into the food. All food contains moisture molecules which, when subjected to microwave energy, begin to oscillate at a rate of 2.5 billion times per second. The friction caused by these vibrations creates heat, which first starts developing around the outside of the food and then slowly penetrates it towards the center. The more water a food contains, the faster it is reheated or cooked.
Because the heat is produced directly in the food:
–The food can generally be cooked using microwaves without adding much liquid or cooking oil.
–Defrosting, heating and cooking is faster than when using a conventional oven.
–Nutrients, such as vitamins and minerals, are generally retained.
–The color, texture and taste of food are hardly affected.
The production of microwaves stops whenever the program is interrupted or the microwave oven door is opened. During operation, the closed and intact door prevents microwaves from escaping the appliance.
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