Loading ...
Loading ...
Loading ...
18
18
Microwaves are present in the
atmosphere all the time, both naturally
and from manmade sources. Manmade
sources include radar, radio, television,
telecommunication links and mobile
phones.
In a microwave oven, electricity is
converted into microwaves by the
magnetron.
Reection
The microwaves bounce off the metal
walls and the metal door screen.
Transmission
Then they pass through the cooking
containers to be absorbed by the water
molecules in the food, all foods contain
water to a more or lesser extent.
Note
The dish used to cook or
reheat the food will get warm
during cooking, as the heat
conducts from the food. Even in
microwaving, oven gloves are
required!
Microwaves cannot pass
through metal and there fore
metal cooking uten sils can
never be used in a microwave,
for cooking on microwave only.
How Microwaves cook food
The microwaves cause the water
molecules to vibrate which causes
friction, i.e. heat. This heat then cooks
the food. Microwaves are also attracted
to fat and sugar particles, and foods
high in these will cook more quickly.
Microwaves can only penetrate to a
depth of 1½ -2 inches (4-5 cm) and
as heat spreads through the food by
conduction, just as in a traditional
oven, the food cooks from the outside
inwards.
Foods Not Suitable for Cooking
by Microwave Only
Yorkshire Puddings and Soufes. This
is because these foods rely on dry
external heat to cook correctly, do not
attempt to cook by micro wave. Foods
that require deep fat frying cannot be
cooked either.
Standing Time
When a microwave oven is switched
off, the food will continue to cook by
conduction – Not by microwave
energy, hence standing time is very
important in microwaving, particularly
for dense foods i.e. meat, cakes and
reheated meals (refer to page 20)
Boiled eggs
Do not boil eggs in your
microwave. Raw eggs boiled
in their shells can explode and
cause serious injury.
Magnetron
Oven Cavity
Turntable
Waveguid
e
Microwaving Principles
Loading ...
Loading ...
Loading ...