What is Hydrogenation? And Why Is It In All Your Food?

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Chances are you’ll eat something hydrogenated today. What does that mean? We’ll give you a quick tour of what hydrogenation is, how it’s done, and why many people don’t like it.

To hydrogenate something is simply to add hydrogen to it. To start the process, you need something that has places where hydrogen can stick. Food manufacturers find this in the long fatty acid chains in non-hydrogenated oils and fats. These fatty acid chains consisted of carbon atoms stuck to each other through double bonds. Each carbon atom is linked to the next one twice over. Adding hydrogen involves ripping one of those bonds apart, so instead of one carbon atom being double bonded to the next carbon atom, the carbon atom has a single bond with the next carbon atom, and a single bond with a hydrogen atom.

The process involves heating the oil up, putting it under pressure, and adding hydrogen. In order to combine them, though, you need a catalyst. The catalyst, in most reactions, is nickel or platinum. (That’s right, it can take platinum to produce trashy food.) This breaks the bonds between the carbon atoms, and hands them over to the hydrogen atoms. Partial hydrogenation results in trans fats, and total hydrogenation results in saturated fats—because the fat is saturated with hydrogen atoms, and can’t take any more.


Companies hydrogenate their fats for all kinds of reasons. Some need just the right melting point. Partially-hydrogenated oils don’t spoil as quickly, so foods that are designed to be on the shelf for a while tend to undergo hydrogenation to ensure that they keep well. When making things like shortening or margarine, you need a solid, “buttery” texture. Unfortunately, as we all know, these kind of fats are bad for you—especially trans fats. They bring up your cholesterol levels, harden your arteries, and inhibit the formation of an enzyme called cyclooxygenase, which helps determine the dilation of your arteries and regulates blood flow. Basically, they glue-up your entire cardiovascular system.

Stupid hydrogen.

Top Image: Aussie Gal