Although microwave ovens are found in most households, few people know what microwaves are, how they work, and how food gets heated quickly. Why are they effective at cooking and how safe are they? Find out in the rows below.
3 Essential Features That Make Microwave Ovens Possible
The reason why they can be used for cooking in microwave ovens is the presence of 3 basic features:
- They are reflected by the metal- the microwaves circulate inside the oven, passing through food, but not through the metal walls.
- They go through paper, glass, plastic and ceramics- for this reason, you can use various containers to heat food in the microwave.
- They are absorbed by food- the main feature that allows heating of food placed in the oven.
How Does the Microwave Work?
The microwaves are generated inside the oven by an electronic tube called a magnetron and circulate, reflected by the metal walls. Microwaves cause water particles to vibrate when passing through food, generating heat.
It is a simple process by which the energy of electromagnetic waves is transformed into heat and the reason why foods richer in water (fruits, vegetables) will heat up faster than the drier ones.
Is It True That Food Is Heated From the Inside?
Although microwaves affect water particles in food, heating also begins from the outside to the inside. The inner layers are heated by convection, by transmitting heat layer by layer from outside to inside.
This explains why the container in which the food is located is warmer in some cases than the food in the middle. The heat is first formed in the outer layers and circulates further in both directions: inwards, in the food, and outwards, in the walls of the bowl or casserole.
Is Microwave-heated Food Poorer in Nutrients?
Studies show that microwave heating does not affect the nutrients in food more than conventional heating. In fact, in some cases, the microwave protects the nutrients so that the food can be cooked with or without less water.
What Containers Do You Use in the Microwave?
The recommended containers for cooking or heating in the microwave are glass, ceramic, plastic or paper. Be careful, though.
Although microwaves pass through these materials and therefore do not heat them directly, the containers gradually take over from the food’s heat. So avoid using plastic containers that melt quickly in the heat because if the food is hot, the plastic walls will inevitably heat up.
Metal pots and pans are not used in these oven models because they reflect the microwave. The food will heat up unevenly and the oven may be damaged.
Microwaves and Liquids
Water heated to close to the microwave boiling temperature is not stirred in the same way as water heated on a stove or electric hob. But if it is too hot and you move the container in which it is or add coffee or ness, you risk bursting and scalding yourself.
Therefore, pay close attention to the heating times recommended by the microwave oven manufacturer in the user manual for liquids.