The orientation of this polar molecule will change with the microwave field. Due to the movement of polar water molecules in food. As well as the interaction between adjacent molecules, it produces a phenomenon similar to friction, which makes the water temperature rise, so the temperature of food also rises.
Microwave is an electromagnetic wave. The microwave oven consists of power supply, magnetron, control circuit and cooking cavity. The power supply provides a high voltage of about 4000 volts to the magnetron. Under the excitation of the power supply, the magnetron continuously generates microwaves, which are coupled into the cooking cavity through the waveguide system.
There is a rotatable agitator near the entrance of the cooking cavity. Because the agitator is a fan-shaped metal, it can reflect microwaves in all directions after rotation, so it can evenly distribute microwave energy in the cooking cavity, thus heating food. The power range of microwave oven is generally 500 ~ 1000 watt.
Extended data:
These foods can't be put in the microwave oven.
1, food with film or shell
Raw eggs are probably the easiest food to accidentally throw into the microwave oven. Many people around us have had the experience of heating raw eggs in a microwave oven. I didn't expect eggs to be heated in the microwave oven, because the heating mechanism will explode in the microwave oven. More dangerously, when the microwave oven is turned on, the eggs may burst open again, which may hurt eyes or other parts.
2. Paper bags, newspapers and plastic bags
After paper products are heated by microwave, high temperature may ignite paper bags, which is very easy to catch fire and may also produce toxic gases. When heating food at ordinary times, we should also pay attention to whether there is a paper part in the package, so we should not be careless.
3. Foods with low moisture content
Such as nuts, pork belly, dried fish and so on. Low water content, particularly rapid temperature rise, easy to burn, easy to produce carcinogens. Therefore, it is better not to use microwave oven to cook these foods, and it is more scientific to use other methods.
Even if you want to use the microwave oven, you should be very careful and strictly control the time. Microwave ovens are not suitable for cooking foods with high salt content, so it is necessary to minimize the amount of salt used to avoid the cooked food from being burnt outside and tender inside.
4. Disposable plastic products
Disposable plastic containers: such as the outer packaging of yogurt, butter or cream, don't throw them into the microwave oven. They are really disposable and can't withstand high temperature. The container may be deformed or melted in the microwave oven, and the melted chemicals will penetrate into the food.
Ordinary plastic containers are not allowed in the microwave oven. One is that hot food will deform plastic containers, and the other is that ordinary plastics will release toxic substances, pollute food and endanger human health. Use a special microwave oven to hold food and put it in the microwave oven for heating.
5. foam lunch boxes
In fact, most daily lunch boxes can be heated in the microwave oven, and sometimes foam lunch boxes can never be heated in the microwave oven, for the same reason that chemicals that release plastics are harmful to human health.
6. Metal products
Tableware such as metal and tin foil. It is not suitable for heating in the microwave oven, because the iron, aluminum, stainless steel, enamel and other utensils put into the furnace will generate electric sparks and reflect microwaves when heated, which will not only damage the furnace body but also heat the uncooked food.
Baidu encyclopedia-microwave oven