A microwave oven, commonly referred to as a microwave, is a kitchen appliance that heats and cooks food by exposing it to microwave radiation in the electromagnetic spectrum. Percy Spencer (An american physicist and radio engineer) is generally credited with inventing the modern microwave oven after World War II from radar technology developed during the war. Since the time of its invention people are having misconception about it due to the simple fact that it uses radiation to cook the food. So in this article I will take a look at some of the facts behind the most common microwave concerns. Do they leave radiations in the food after cooking? Do they leak radiations? Do they destroy nutrients in the food? Do they denature proteins and make food toxic to our bodies? First though, let us start with basics, what are microwave radiations and how does the microwave oven work?
What are the microwave radiations?
Microwaves are a form of "electromagnetic" radiation; that is, they are waves of electrical and magnetic energy moving together through space. Electromagnetic radiation ranges from the energetic x-rays to the less energetic radio frequency waves used in broadcasting. Microwaves fall into the radio frequency band of electromagnetic radiation. Microwaves should not be confused with x-rays, which are more powerful. The Em wave spectrum looks something like:
Microwaves have three characteristics that allow them to be used in cooking:
- they are reflected by metal
- they pass through glass, paper, plastic, and similar materials
- they are absorbed by foods.
How do microwave ovens work?
Microwaves are produced inside the oven by an electron tube called a magnetron. The microwaves are reflected within the metal interior of the oven where they are absorbed by food. Microwaves cause water molecules in food to vibrate, producing heat that cooks the food. That's why foods high in water content, like fresh vegetables, can be cooked more quickly than other foods. The microwave energy is changed to heat as it is absorbed by food, and does not make food “radioactive” or "contaminated." Working can be understood by following line diagram:
Although heat is produced directly in the food, microwave ovens do not cook food from the "inside out." When thick foods are cooked, the outer layers are heated and cooked primarily by microwaves while the inside is cooked mainly by the conduction of heat from the hot outer layers.Microwave cooking can be more energy efficient than conventional cooking because foods cook faster and the energy heats only the food, not the whole oven compartment. Microwave cooking does not reduce the nutritional value of foods any more than conventional cooking. In fact, foods cooked in a microwave oven may keep more of their vitamins and minerals, because microwave ovens can cook more quickly and without adding water.
Do microwaves leak radiation?
One concern many people have about microwave ovens is the simple fact that they emit, well, microwaves. Hasn’t exposure to microwave radiation been linked to cancer and infertility? Evidence is mixed; most published research concludes that low-level microwave exposure doesn’t present a significant risk to human health. Even if it did, this is only an issue if the microwaves inside the microwave somehow escape the microwave and encounter your body, which is unlikely.The FDA(U.S. food and drug administration) requires that microwaves emit no more than 5 mW/cm2 of radiation at a distance of 2 inches from the microwave. They also point out that microwave radiation dissipates rapidly as you move away from the source, so a measurement taken 20 inches from the microwave would be about 1/100 of the measurement taken at 2 inches. This is good news, because it means that to avoid radiation from your microwave, all you have to do is step away from it while your food is heating.
Honestly, just don’t press your face up against the door of the microwave while your food is cooking, and step a few feet away if you can. If you’re going to be concerned about exposure to microwave radiation, you’d probably be better off getting rid of your cellphone than your microwave oven.
Do microwaves destroy nutrients and make proteins toxic?
As far as vitamins, minerals, antioxidants, and plant phenols, retention does not appear to depend on cooking method. Levels of nutrient retention were sometimes higher in microwaved food, and sometimes lower, depending on time, temperature, and amount of water used in the cooking process.In general, nutrients are lost from food during any type of cooking, and more nutrients are lost when the temperature is higher or the food is cooked for longer. Water soluble vitamins are readily leached into cooking liquid (no surprise there), so boiling food tends to result in greater nutrient losses than microwaving it with a small amount of water (unless you drink the water you boiled the food in, in which case you’d still be getting most of the nutrients).
Don’t fear the microwave!
In conclusion, microwaves aren’t as scary as some people make them out to be. Yes, they’re another source of microwave radiation in your home, but the levels are extremely low, and can be almost entirely avoided by simply stepping away while your food is heating. And compared with microwave radiation from other devices (particularly cell phones), radiation from your microwave oven is negligible.
Additionally, there’s no evidence that microwaves adversely affect the nutrient profile of foods. Because microwaves are a relatively new device, I prefer to think of them as “guilty until proven innocent” rather than the other way around, but given what we know about EM radiation and its effects on food molecules, there isn’t really a mechanism by which microwaves could destroy nutrients other than heat. And heat, of course, is an issue regardless of cooking method!
Tips on Safe Microwave Oven Operation
- Follow the manufacturer's instruction manual for recommended operating procedures and safety precautions for your oven model.
- Don't operate an oven if the door does not close firmly or is bent, warped, or otherwise damaged.
- Never operate an oven if you have reason to believe it will continue to operate with the door open.
- As an added safety precaution, don't stand directly against an oven (and don't allow children to do this) for long periods of time while it is operating.
- Users should not heat water or liquids in the microwave oven for excessive amounts of time.
While I strive to provide as accurate and balanced information as possible on my Blog, This blog cannot guarantee its accuracy or completeness because there is always more research to do, and more up-to-date research studies emerging -- and this is especially the case regarding research on the health and environmental effects of plastics. Therefore I do not hold any responsibility for the damage caused by using this information
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