Food is the elixir of life. So, care should be taken to have hygienic and nontoxic food. Microwave oven stands there for that purpose. It is a kitchen appliance that cooks food by using microwaves in the electromagnetic spectrum. For shorter wave lengths, there will be more energy in microwaves. This energy in microwaves is ample to vibrate the organic molecules in the food and thereby produces heat. Microwaves judder approximately 2.5 billion times per second. Microwave ovens heat food without affecting the container. Containers made of plastic, paper, glass, ceramic can be used for cooking in microwave ovens, as they are impervious to microwaves as well as they allow the waves to pierce them.
These waves are reflected by metal facades. Because of this, the microwave oven has metal coating inside so as to reflect the microwaves produced by magnetron to pass through the food again and again. Ceramic cook wares are largely preferable. The cookware should be kept open.
Microwave oven requires high voltage transformers for supplying current to magnetron which in turn ignites electrons to produce microwaves of desired frequency, inside the oven. There will be a micro-controller and a cooking chamber to facilitate cooking.
Inspite of having microwave ovens in your kitchens,a good number of you may be unaware of how it works.
It commences its work by passing microwave radiations, which are non-ionizable, through the food item, at a frequency of 2.45 GHz. These microwaves are generated by magnetron, the tube of electrons which is to be had inside the oven. By means of dielectric heating, water, sugar, fats etc. in the food absorb energy from the radiation. Since the microwave ovens use non-ionizable radiations, there won't be any risk of having cancer. Heat is said to be the movement of molecules. Many polarized molecules in the food like water have both positive and negative charges in them.
Based on the alternating electric field produced by the microwaves, the charges tend to align themselves which leads to the movement of molecules whose collision leads to heat. This heat cooks the food. As the microwave energy is immediately converted into heat, there is no harm of radioactivity in the cooked food. Food with more water content is cooked against the clock in comparison with those with less water. This technique causes the outer layers to get heated up first and foremost and from there, the heat is conducted to the inner layers.
The intensity of penetration of microwaves depends on the frequency and food composition. The lower the frequency, the greater is the rate of penetration.
In conservative ovens, the cooked food and the cookware will be at the same temperature which is not seen in case of microwave ovens. Here the cookware will be cooler than the food, because, the microwaves penetrate the cookware and heat the food first and from that one, the cookware is heated indirectly. The microwave oven expends less energy than conventional ovens, as it cooks faster only the food but not the cookware. These ovens don't trim down the nutrition value of the food as it cooks more rapidly.
As it depends on the amount of water used, steaming vegetables in microwave oven results in retaining 77% of nutrients, when compared with heating in stove.
Microwave ovens are used in restaurants, homes, industries, as they are both energy efficient and time efficient, supporting good quality. These microwave ovens are normally used for preparing food and reheating old stuffs in few minutes. Microwave ovens have some limitations, as they are not suitable for flavor-enhancing reactions, browning etc. Sometimes, bacterial destruction is not possible if it doesn't reach the appropriate temperature. This may lead to illness. Apart from these limitations, the role played by microwave oven in day-to-day life is highly appreciable.
