by Steven Gomez

Created on: January 16, 2011   Last Updated: January 18, 2011

The major misconception with the microwave oven is that it cooks food the same way a conventional oven, grill or stove top does.  However, the microwave oven does not emit heat as the other methods do.  Below is a description of how the microwave oven uses unique molecular and kinetic properties to heat food in a way different from all other hot cooking methods, as well as create risks unique from the other methods.

The microwave oven is named after the microwaves (radio waves) the device uses to heat your food.  The oven emits radio waves at 2.45 gigahertz, a frequency where sugars, fats and water can absorb them and convert them into heat through vibrating atomic motion that bump together, generate kinetic energy and in turn heats most food.

Water molecules consist of atoms (2 parts hydrogen, 1 part oxygen) with constantly moving protons and electrons.  The microwave energy creates constantly shifting electric fields which change the rate and direction in which these protons, electrons and, in turn, the molecules move.  This continuous shift in movement is what generates the energy that cooks your food, a contrast to other conventional cooking methods where the food cooks by drawing in an outside source of heat.

Given this, microwave ovens only work with foods that contain some volume of water.  Dry foods will not cook in a microwave oven, and solid items like plates and food containers will not cook.  Metal can also reflect the microwaves, which can cause damage to the oven; This in turn is why you aren't supposed to use metal in the microwave.

A microwave can only heat what its waves can penetrate, which is why frozen foods tend to have a difficult time cooking in the microwave.  The frozen water molecules can't rotate as quickly as needed until those icy molecules have melted.  Thus the heat generated on the outer layers of the dishes must thaw the interior frozen part through conduction before the microwaves can heat that internal portion.  This is why frozen dishes often have a well-cooked outer layer with a cold inner layer after heating.

One obvious side effect of the microwave's difference in cooking is that the microwaves can also break down nutrients in food and reduce the nutritional value of what's consumed, as well as leech harmful chemicals from food containers into the heated food.  The ovens themselves also emit trace amounts of radiation that can further break down food as well as harm the human body over a period of extended exposure.  This is also why one shouldn't stand in front of or near a microwave oven.  It's best to use a microwave oven incidentally and otherwise sparingly to avoid long-term exposure to these dangers.

The microwave oven has its uses as a quick cooking resource through its unique technology.  This technology also provides a host of other risks and drawbacks that makes it a resource one should use selectively.

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