I am slowly, but surely, deciding on the subject matter of this blog. I want to make science less scary. There are a great number of blogs and posts and Twitter-er-ers that are dedicating their free time to showing the non-scientific just how cool, and not terrifying, science can be! From Chemistry to Physics to Biology, science is all around you. So imagine my surprise when I saw this:
“…was microwaving some food in the break room when a coworker said, “You know, microwaves change the molecular structure of food.”
-Reddit User Bartink
Every house in the world (probably hyperbole) has a microwave. Hell, I’ve got two of them in my kitchen. I call the one that works Chef Mike and the one that doesn’t storage. The coworker’s statement is true, but the concern (of chemical changes in food) is not. Luckily, /u/Bartink isn’t afraid of the world around him and knows that cooking involves chemical (molecular) changes. So let’s start simple: What is a chemical change/process? According to Fred Senese of the Frostburg State University’s Department of Chemistry:
Chemical change is any change that results in the formation of new chemical substances. At the molecular level, chemical change involves making or breaking of bonds between atoms. SOURCE
When teaching high school chemistry, it’s often necessary to discuss how chemical changes are irreversible. This isn’t entirely true – but let’s go with it. Let’s assume I’ve got a beautiful T-bone steak and I’ve tossed it into a hot pan with a little butter. Immediately, the meat sizzles, heats, and the bottom surface browns a little. This browning is a result of what is known as the Maillard (pronounced my-er) Reaction. The Maillard Reaction is a complex series of reactions between sugars and proteins that causes a brown color on the surface that is exposed to heat. This is a chemical change. We don’t need a microwave to “[change] the molecular structure of food” – cooking does that all on its own.
So next, the question becomes – What the hell does the microwave do then? Microwaves use microwaves! Microwaves are radio waves with wavelengths as long as 1 meter and as small as 1 millimeter. These waves penetrate the food and act on the fats, water, and other molecules in the food. Molecules which are polar, have a slight charge on one end, align themselves with the direction of the electric field in the microwave. Because we use an alternating current, the direction of the field alternates. For the same of simplicity, assume the field direction is up and then alternates down, up, down, up…on and on and on. These molecules absorb energy and bump other molecules in the food and spread the heat around. Some people think that microwaves make only the water molecules vibrate – but the truth is that all of the semi-charged molecules vibrate to some extent and cause the heating of the food.
Adding energy to a substance is often the cause of a chemical change. So yes – the microwave adds energy to your food. This energy is in turn converted to heat and your food is cooked.
The microwave may be a devil-box as far as Momma is concerned. But it is not spewing radiation into your house (thanks to those cool screens on the front) and it’s not making your food toxic. Y’all really needn’t worry.
I know this isn’t entirely chemistry related, but I’m still collecting my data for a successful cinnamon roll with a delicious bourbon glaze. Just wait.