How the microwave oven functions

How does the microwave oven function?

In a microwave oven there is a high-frequency tube called a magnetron. This converts electrical energy into microwaves. These microwaves are distributed evenly throughout the oven interior and rebound off the metal sides of the oven interior to reach the food from all sides. Microwave distribution is improved with the turntable engaged.

In order for microwaves to reach the food, they must be able to penetrate the cooking utensil being used.

Microwaves can penetrate porcelain, glass, cardboard and plastics, but not metal. Do not, therefore, use utensils made of metal, or which contain metal, for example in the form of gold or silver trim. The metal reflects the microwaves and this could lead to the creation of sparks. The microwaves cannot be absorbed.

Microwaves pass through a suitable container and find their way directly into the food. All food contains moisture molecules which, when subjected to microwave energy, start to oscillate 2.5 thousand million times a second. The friction caused by this vibration creates heat, which first starts developing around the outside of the food and then slowly penetrates towards the centre. The moisture, fat and sugar content of food will affect the speed at which it is cooked.

As heat is produced directly in the food,

–food can generally be cooked without adding much liquid or cooking oil.

–cooking, reheating and defrosting in a microwave oven is quicker than using conventional methods.

–nutrients, such as vitamins and minerals, are generally retained.

–the colour, texture and taste of food are not impaired.

Microwaves stop being produced as soon as the cooking process is interrupted or the appliance door is opened.

When the appliance is in operation, the closed, sealed door prevents microwaves escaping from the appliance.