Why Does Cooking Turn Your Food Brown?

“Bread” by Kate Remmer on Unsplash

If you have ever had steak, french fries, coffee, or bread, you’ve literally tasted the results of the Maillard reaction. The Maillard reaction was named after a dude with a cool name (French chemist Louis-Camille Maillard) in 1912.

The Maillard reaction is many small, simultaneous chemical reactions that occur when proteins and sugars in your food are completely transformed by heat.

It’s basically what causes our food to brown when we heat them up. Under the hood, let’s look at the chemistry behind barbarically subjecting our foods to the level of Mercury’s surface temperature at 280 to 330 °F (140 to 165 °C).

Three Chemical Steps for Maillard

1. The carbonyl group (from the sugar) reacts with an amino group (from the amino acid). Which produces N-substituted glycosylamine.

The C’s and O’s in sugar are the carbonyl groups (C=O)

Okay, but what is this shit?

Carbonyl Group: It’s a carbon atom double bonded to oxygen. Basically back in chemistry class whenever you saw C=O on those diagrams (aka structural diagrams).

Amino Group: Found in like basically all proteins (aka amino acids). When you see -NH2, that’s an amino group.

Glycosylamine: This looks weird af, but it’s not. It’s just a glycosyl group (something that can come from carbohydrates) together with an amino group. Gylcosyl + amino?? Glycosylamine, they weren’t even creative.

2. Now the gylcosylamine product from before is pretty damn unstable (will and can react easily to form other things). So it undergoes an Amadori rearrangement, which produces ketosamines.

The Enaminol thingy is a process in the Amadori rearrangement.

Amadori rearrangement: Fancy name of an average organic reaction. Named after a dude named Amadori.

Ketosamines: You can guess this one. It can’t be something called ketose and an amino acid/ group together right? That’s exactly what it is.

3. Now all those ketosamines further react in a bunch of different ways, forming this and that, and reacting more.

In “basic” conditions we get the stuff on the left. In “acidic”, the stuff on the right.

The hodgepodge mess of reactions at this stage will start producing a bunch of different things, concluding the Maillard reaction.

To Conclude

At this point, your food’s getting brown af. And you’ll start deciding whether to take it off the stove. But by the time that happens, these reactions we just talked about happened trillions and trillions of times over on the atomic level. Next time, you can thank chemistry instead of just your superb cooking skills for that damn delicious dish you made.