I remember the days when we prepared foods without
microwaves, we used firewood, the stove and those who were privileged to have
gas they were found to be rich. Today, the evolution has gone to instant
cooking and warming of food without having to wait for hours before it is
ready.
Microwaves have become the norm in many kitchens in Kenya,
at home, restaurants and even in offices. But just how safe is the food you
heat in the microwave? What are the dangers you expose yourself to when using
it? How best to use the microwave? These are the many questions Kenyans and
people using the microwave keep asking.
This blog is all about the facts, the myths and the
misconceptions about this device that has become somehow inevitable to use.
In the first place it is vital to understand just how
does this device work?
Microwave oven uses electromagnetic waves called
micro-waves to heat food. No wonder the name of the appliance is; microwave
oven. The micro-waves oscillate at a very high speed, normally 2450 times per
second.
When food is placed in a microwave oven, various
food ingredients behave differently. The main ingredient that enables food to
be heated by micro-waves is water. The higher the water contents in food,
the faster the heating rate. Water in molecular level behaves exactly like a
magnet. Water has two oppositely charged ends due to presence of positively
charged 2 Hydrogen atoms and a negatively charged Oxygen molecule. Therefore,
water in food behaves like a magnet. If a bar magnet is held above another bar
magnet, and you rotate the held magnet, the other one also rotates.
Similarly, due to two different poles in water, when micro-waves oscillate the
water molecules rotate. This is because the negatively charged end of water is
attracted to positively charged end of micro-wave, while the positive end of
water is attracted to the negative charged end of micro-waves.
The micro- waves rotate at extremely high speed
of 2450 time per second. This means for every second a micro-wave rotates, the
water molecule also rotates 2450 times. This extremely high rotation rate
causes water molecules to collide with each other at very fast rate. This
creates friction between water molecules. This friction generates heat. The
heat flows through the food by conduction, convection or radiation. Therefore
food warms up. That is simply how microwave heats food.
Facts:
You
Can't Heat Oils in a Microwave
Oils such as olive oil do not heat
well in microwaves because their molecules lack the polarity found in water.
It's also true that frozen butter is hard to thaw in a microwave, because the
bulk of the substance is oil, and the portion of water present is in the form
of ice, which keeps the molecules locked up in crystal form, making oscillation
more difficult.
Some foods explode or generate sparks when heated in microwave ovens.
Foods that explode when heated in a microwave
include eggs. So, they should not be heated in a microwave.
Boiling
a Cup of Water in a Microwave Can Cause It to Explode
one potential danger of microwave ovens is getting scalded by over heated water.
What can happen is that when plain water is heated in a microwave in a clean
ceramic or glass container for too long, it can prevent bubbles from forming,
which normally cools it down. The water can become superheated, past its
boiling point. So when it is disturbed, say by moving it or dropping something
in it, the heat releases violently, erupting boiling water out of the cup.
To avoid this risk heat water only
the minimum amount of time needed. Or place a wooden spoon or stick in it (you
should be fine with a metal spoon too, as we discussed above. Don't use a metal
fork though, which could spark.)
Myths:
Metals
Get Dangerously Hot in Microwaves
Metals reflect microwaves, whereas plastic, glass and ceramics allow them to
pass through. That means metals don't appreciably heat up in a microwave oven.
However, thin pieces of metal, such as foils or the tines of a fork, can act as
antenna, and the waves can arc off them, forming dramatic sparks.
Microwave
Ovens Cook Food from the Inside Outside
Although many people believe this to be the case, microwaves actually work on
the outer layers of food, heating it by exciting the water molecules there. The
inner parts of food are warmed as heat transfers from the outer layers inward.
This is why a microwave can only cook a big chunk of meat to a depth of about
one inch inward.
Micro-waves leak through the glass door?
No. The glass door helps to see inside the oven while it has a mesh to prevent
micro-waves from leaking out.
So
what to do?
If
you use a microwave:
- Don’t heat
food in plastic.
- Make sure
food reaches 160 degrees F in all areas (you have a food thermometer,
don’t you?).
- Cover food
to help ensure uniform cooking.
- Allow the
food to sit a few minutes after microwaving.
- Microwave
food only as long as necessary, with little to no cooking water.
If you don’t use a microwave:
Continue to heat food over gas,
stove, jiko or any other means since you exempt yourself from the risk of losing
food nutrients, causing some illnesses especially IF your model leaks radiation
when heating or cooking food.
Go check whether your microwave
leaks radiation by:
- Find
a fluorescent tube or bulb
- Darken
the room
where the microwave sits
- Hold
the bulb against the edges of the microwave ovens door when the oven is in use. While normally
it is not recommended to use the microwave with nothing inside it, in
this short experiment, it is best not to add anything to the oven.
- Check
for a reaction.
If there is microwave leakage occurring, the bulb will glow.
From
here you know what to do! Discard your microwave or have it fixed!
I
love questions add them on the comment box below or email me on:
ndutaniceness@gmail.com
I must say that am excited about this year and the way it has began for me. I would love to hear how you battled with the chicken, goats, cows, fish, ugali, rice, chapati and emerged victorious without gaining too much weight that you probably were not sure about!
