Whenever I tell people that my PhD thesis was on microwave heating of foods, they look at me with awe and ask endless questions. One of the common question is simple but very touch. They ask me whether warming food in a microwave oven is safe. I respond with resounding Yes.
Microwave oven is a modern convenience appliance in every kitchen in the developed countries. However, it is not the case in many homes in developing countries, but the use of microwave ovens is picking up at a tremendous rate. All of the users of microwave oven are always interested in knowing how it works.
In this article, I will outline how microwave oven works.
How Microwave Oven works
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 content 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.
Does micro-waves remain in food after warming food?
No. Microwave are never embedded in food therefore microwaves are not left in food following warming of food.
Is Microwaved food safe?
Yes. Microwaved food is safe for human consumption.
Common uses of microwave oven
-Thawing of frozen foods such as meat, bread etc.
-Warming ready-to-eat foods.
– Warming chilled foods
Foods that should not be heated in a microwave.
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.
Items that should not be used in a microwave
Never put any metallic object e.g spoon or metallic dishes in the microwave oven. Metals reflect micro-waves and hence generates sparks.
Use only microwave-safe plastics when warming food in a microwave. Some plastics when heated in a microwave, the compounds leach into the food and maybe dangerous to health
Can 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.
If you have any question, please feel free to leave it in comments section below.