9
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 car
phones
.
Microwaving Principles
The microwaves cause the water molecules to
vibrate which causes FRICTION, ie. 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 1
1⁄
2
-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.
In a microwave
oven, electricity is
converted into
microwaves by the
MAGNETRON
REFLECTION
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.
IMPORTANT NOTES
HOW MICROWAVES COOK FOOD
The dish used to cook or reheat
the food will get warm during
cooking, as the heat conducts
from the food. Even in
micro waving, 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
Foods Not Suitable for
Cooking by Microwave
Only
Yorkshire Puddings, Souffles,
Double Crust Pastry Pies.
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 10).
Boiled Eggs
Do not boil eggs in your
microwave. Raw eggs boiled in
their shells can explode and
cause serious injury
13 Amp fused socket
Microwave
Water
Molecule
Absorption
Vibration