Microwaving Principles - Panasonic NN-CT54JW Operating Instruction And Cook Book

Microwaving Principles

Microwave energy has been used in
this country to cook and reheat food
since early experiments with radar in
World War II. 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.
How Microwaves Cook Food
Turntable
Reflection
The microwaves bounce off the metal
walls and the metal door screen.
In a microwave oven, electricity is
converted into microwaves by the
magnetron.
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.
20
Oven Cavity
Magnetron
Waveguide
20
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 4-5 cm (1½-2 inch) and
as heat spreads through the food by
conduction, just as in a traditional
oven, the food cooks from the outside
inwards.
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
therefore metal cooking
utensils can never be used in
a microwave, for cooking on
microwave only.
Foods Not Suitable for Cooking
by Microwave Only
Yorkshire puddings, souffles, double
crust pastry pies. 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 21).
Boiled Eggs
Do not boil eggs in your
microwave. Raw eggs boiled
in their shells can explode and
cause serious injury.