26
GB
Advantages of the microwave oven
In a conventional cooker, the heat that is radiated
through the resistances or gas burners slowly
penetrates the foods from the outside in.
Therefore, there is a great loss of energy in
heating the air, the oven components and the
containers holding the food.
In the microwave, the heat is generated by the
foods themselves, i.e. the heat goes from the
inside out. There is no loss of heat to the air, the
walls of the cavity or the containers (as long as
they are microwave-safe containers). This means
that only the food is heated.
To sum up, microwave ovens have the following
advantages:
1. Savings in cooking time; in general, there is a
¾ reduction in time compared to conventional
cooking.
2. Ultra fast defrosting of foods, thus reducing the
danger of bacteria developing.
3. Energy-saving.
4. Conservation of the nutritional value of foods
due to the reduction in cooking time.
Microwave oven operating mode
The microwave oven contains a high voltage
valve called a Magnetron, which converts the
electrical energy into microwave energy. These
electromagnetic waves are channelled towards
the inside of the oven by a wave guide and
distributed using a metallic disperser or a rotating
plate.
Inside the oven, the microwaves are propagated
in all directions and reflected by the metallic walls,
thus uniformly penetrating the foods.
Why the food is heated
Most foods contain water and the water
molecules vibrate with the microwaves.
The friction between the molecules generates
heat, which raises the temperature of the foods,
defrosting or cooking them or keeping them hot.
Because heat is formed inside the foods:
•
The foods may be cooked without any liquids
or oils, or with very little of these;
•
Defrosting,
heating
or
cooking
in
the
microwave oven is faster than in a conventional
oven;
•
The
vitamins,
minerals
and
nutritious
substances are conserved;
•
Neither the natural colour nor the aroma are
altered.
The microwaves go through porcelain, glass,
cardboard or plastic, but not trough metal. For this
reason, metallic containers or containers with
metallic parts should not be used in the
microwave oven.
Microwaves are reflected by metal...
... they go through glass and porcelain...
... and are absorbed by the foods.
