Radiation And the Microwave Oven

Radiation Involves the transfer of heat in the form of waves through space. The microwave oven uses radiation to cook food. Broiling, grilling and rotisserie cooking use radiant heat. Is responsible for most browning of foods.

The Microwave Oven Has an electron tube called a magnetron tube which converts electrical energy into microwaves. Microwaves are actually low frequency waves of radiant energy.

Microwaves are about the diameter of a pencil and are about 1 ½ inches long. Cannot pass through metal. Can penetrate paper, glass and plastics. Can only travel in a straight line.

When microwaves penetrate a piece of food, it causes the particles to become agitated and move around. The movement causes friction, which produces heat. The heat cooks the food.

Foods that are high in water, fat and sugar are more easily agitated and therefore cook faster than other foods in the microwave oven. Foods with a high water content cook the fastest of all. Many foods have a high water content.

Microwave ovens have “hot spots” Since the magnetron tube is located on one side of the oven, the microwaves bounce around in an uneven pattern. Certain areas in the oven will get hit more frequently. Dishes need to be turned halfway through cooking time, food should be stirred when possible or a turntable should be used if one is available to promote even cooking.

Microwave Tips: Do not worry ~ the size of a microwave is larger than the tiny holes in the metal screen behind the glass in the door,so the waves cannot escape. Microwaves bounce off metal. Do not try to cook in a metal pan or on foil. The microwaves will not be able to penetrate the food and it will not cook! The heat from food will transfer to the dish,so always use pot holders.

Steam can build up in tightly sealed foods or containers and cause them to explode. Always pierce vegetables or fruits with thick skins as well as egg yolks. Never try to cook eggs in their shells. Vent plastic coverings on dishes. Use a turntable or rotate the dish halfway through the cooking time so that the food will cook evenly. Food will continue to cook for several minutes after the microwave stops, so allow for approximately five minutes of “rest time”.