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Microwave oven function:
In a conventional oven the heat radiated by the
resistances or gas burners, slowly penetrates the food
from the outside to the inside. There is, therefore, a
great loss of energy in the heating of the air, oven
components and recipients.
On the other hand, in microwave ovens the heat is
generated in the interior of the food itself, heating it
from the inside outwards. There is therefore no loss of
energy as the air, interior walls of the oven and
recipients (when adequate) do not heat up with
microwaves.
Microwave ovens have the following advantages:
1. Save on cooking time: in general there is a 3/4
reduction of the cooking time than with conventional
methods.
2. Ultra-quick defrosting that prevents bacteria
development.
3. Electricity saving.
4. Maintaining the nutritive value of the food due to the
cooking time reduction.
5. Easy cleaning.
In the microwave oven there is a high voltage valve
called "Magnetron" that converts electric energy to
Microwave energy. These electromagnetic waves are
conducted to the inside of the oven cavity by means of
wave-guide and spread by a mode stirrer or by a
turntable.
Inside the oven, the Microwaves spread out in all
directions and are reflected by the metallic walls,
penetrating the food evenly.
Most food contains water, whose molecules vibrate
with Microwaves.
The friction between the molecules generates heat,
which causes a temperature rise in the food, defrosting
it, cooking it or keeping it warm.
As the heat is formed inside the food:
-
It may be cooked with little or no liquid or fat;
-
Defrosting, heating or cooking in the microwave oven
is quicker than in a conventional oven;
-
Vitamins, minerals and nutritive substances are
preserved;
The Microwaves pass through porcelain, glass,
cardboard and plastic but not through metal.
Therefore, recipients made of or containing metal
should not be used in the microwave oven.
The Microwaves are reflected by the metal…
…they pass through Glass and Porcelain…
…and they are absorbed by the food.
