Does Food Change on a Molecular level when Microwaved?

Hello there, I am happy to share that I brought my first microwave oven in the last week. It looks really good along with some best specifications. As I am new to my microwave oven and I started exploring the details of the product. During my search, a question was grabbed my attention and it’s like, Does Food Change on a Molecular level when Microwaved

Does food Change on a Molecular Level When Microwaved?

For this, I made research from the basics and found an answer like, Absolutely “NO”, because the intensity of the microwaves does not have enough energy to change the chemical composition of the food. Moreover, the water molecules are the main reason behind the heating of the food. So, there is no chance for a molecular level change. Though it doesn’t change the molecular level, microwaving creates some hot/cold spots in food.

But some other researches say that it changes the molecular structure of the protein. If that happens so, let us find the reasons for it.

And If you are curious about the actual things that happen while heating the food, how the heat produces, how hot/cold spots create then kindly have an upward swipe.

Wait…Before getting into the main topic of what actually happens while heating food let us know how heat production takes place in an oven.

How Microwave Oven Works?

This a common question runs in our mind when we brought a microwave oven or when a problem happens with it.

microwave oven food molecular change

In general, the working of a microwave oven depends on the 4 parts of it. Namely

  • Magnetron (produces microwaves)
  • Waveguide (traveling medium for microwaves)
  • Stirrer (looks like a fan and used to spread the microwaves)
  • Turn-able plate (Turnable motion will let the food to rotate and cook it evenly)

Firstly, the magnetron is the key element for the production of microwaves in the oven. This magnetron is a vacuum element, which receives electricity and converts it into microwaves. ( Click here to know the physics behind how a magnetron works)

These microwaves pass towards the inner cooking chamber of the microwave oven through a waveguide like a tube.

Here, the microwaves pass to the stirrer a fan-like structure and let the microwaves to spread all over the closed container after it passed through a waveguide.

As the container is coated with the reflecting material inside, the waves then get reflected and bounce back results in to and froth motion.

During this reflection, the microwaves then release energy in the form of the radiation.

Process of Microwave Heating Food

The microwaves after the reflection get to penetrate into the food which contains water molecules.

After the penetration, the microwaves react with the water molecules. The microwaves make the water molecules to vibrate.

Here water molecules will vibrate for a million times per second. So, this leads to friction and results in heat production.

So, it was clear that there is no change in the molecular level takes place while microwaving the food.

Check out the video of the heating process in the oven

Formation of Hot/Cold Spots:

As said earlier, apart from the molecular level change, there are some consequences like forming hot/cold spots, we face when the food is microwaved. However, the formation of these cold spots will let the bacteria to alive and cause food poisoning.

Reasons for the Formation of Hot/Cold Spots:

I found that these 2 reasons cause cold/hot spots in microwaved food. Namely,

Due to Standing waves of microwaves

The standing waves formed due to the to and fro motion of the microwaves. These waves have nodes that are at the center of both the highest and lowest energy points and anti-nodes which are at the highest and lowest energy points.

When it comes to the main point, the areas of nodes cause less heat which results in the cold spots whereas the areas of anti-nodes heat the food which results in hot spots.

Shape and size of the food

It is also the reason for the formation of the cold/hot spots because the microwave penetrates into the food within 2 centimeters. It cooks the food within the width of 2 centimeters and leaves the remaining part as uncooked. So, the irregular shape and size of the food lead to the formation of cold spots.

Some other Researches:

Well, some other researches are saying that microwaving food can change the molecular levels. Like,

Loss in protein

Researches say that the vibration of the water molecules causing damage to the protein structure. Like, the vibrations are breaking the hydrogen bond and sulphuric bridge.

This results in making the food as the protein less. But there is no scientific proof behind it to prove.

Making nutrition less

Similarly, the vibration of water molecules causing disturbance to the nutritional structure of the food, and results in making the food as nutrition less.

Inactive B12 Vitamin

B12 Vitamin is the best source to help us from causing anemia. These researches say that, if we keep the food which is rich in B12 Vitamin like Beef, Pork, Salmon, Cereals..etc, then microwaves convert this vitamin to an inactive vitamin.


So with all the above information, it was clear that no microwaves can change the molecular structure of food which is cooked in a microwave oven because the water molecules are the only reason for the heat production in microwaves. So, it’s your turn to make or bake the food which you like the most. Happy Cooking!!!

Frequently Asked Questions:

Does Microwave Change the food Taste? No, the microwave cannot change the taste of the food. Because the microwaves are not that much effective to change the chemical composition of food as there are short radio waves with less intensity to react.

What is the molecular level? It is a common word uses in biology and physics. It is the level of the molecules that used to make up the cell structure or to examine the cells.

Do microwaves alter food DNA? No, as said earlier it does not have that intensity to change the chemical composition or DNA of the food. So, it is safe to eat microwaved food without a doubt of changing the DNA of food.

Why do microwave meals need to stand? It is recommended to stand the meal for a while after microwaving it. Because this stand will allow the food to sit in the oven and also helps to reduce the hot spots. The maximum standing time is nearly half of the microwaving time of the food.

Do we have to cover food in a microwave? Yes, covering the food with a lid or with an oven-safe plastic wrap will help to retain the moisture of the food and also heat.

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