The Science Behind Cooking: What Actually Makes Food Brown?

Taken from Google Images

Ever wonder why your meat patties in your Ramly burgers taste charred and seared? Or the GSC popcorn you just bought have toasty, cracker-like flavors? Why does your cup of Starbucks hot coffee taste robust and aromatic?

Has it ever crossed your mind that what made these food taste out of the world? How do these food whose original forms aren’t that appetizing become so irresistible after being cooked? Where do they get the golden-brown like colour?

Turns out, it is all due to a certain chemical reaction recognized as Maillard reaction. Maillard reaction is named after the French chemist, Louis-Camille Maillard who discovered it in 1912. In layman terms, Maillard reaction is known as the browning reaction. Basically, it is a chemical reaction between amino acids and simple sugars in food which then leads to the formation of brown colour.

A photo of Louis-Camille Maillard

(Taken from Google Images)

During the process, simultaneous chemical reactions occur when amino acids and simple sugars in the food are transformed by the heat applied. Hence, the reaction forms brown pigments in a specific way where amino acids and simple sugars are arranged in rings. These rings reflect light in a way which gives the brown colour to the food.

The diagram above demonstrates the process of Maillard reaction 

(Taken from Google Images)

For Maillard reaction to occur, you need to apply high heat to the food. The heat required should be high enough (more than the boiling point of water, 100°C). High heat will dehydrate the surface and remove enough moisture to allow rapid Maillard reaction. Upon reaching more than 149°C, Maillard reaction starts to form the brown colours and emits nice aromas. 

Apart from that, water should be absent as water will not get hotter than the boiling point. Hence, this explains why food fried in oil are able to brown since oil has a higher boiling than water.

In the food industry, Maillard reaction is normally used in the browning of meats for steak and gives the umami taste in fried onions. It is also widely used in roasting coffee and creating crust in baked products such as bread, pies, and cookies. The process also takes place in making malted barley and chocolate. Without Maillard reaction, our favorite French fries and chips will not have the mouth-watering golden brown color and crunchy texture.

Before trying out the Maillard reaction, do remember that raising the temperature even higher than  180 °C will lead to the start of a completely different reaction which is pyrolysis. Pyrolysis is a dangerous reaction which causes food that is charred to be bitter and cancerous.

 So, the next time you dig into your food or begin cooking, say your thanks to Maillard reaction as without it, your food will never taste the same again!

COOKING TIPS!

To speed up Maillard reaction, do follow the tips below.

1. Dry the meat before cooking. 

You can either dab it with a towel or air-dry the meat. Or you can salt the meat in advance for more than 45 minutes or an hour. This is because salt draws out the moisture and salty brine is reabsorbed. Hence, the meat is more tender. 

This happens when meat has undergone Maillard reaction. It looks juicy and inviting
(Taken from Google Images)

2. Use fast heating 

If you are running out of time, you may opt for fast heating. Use deep fryers or blowtorches to speed up the Maillard reaction. 

3. Coat the food with flour

Maillard reaction requires simple sugar and starches break down in the presence of heat to simple sugar. Therefore, starches will be able to provide more materials (in this case, sugar) for the reaction to occur. 

References:

Nathan (March 20,2013) The Maillard Reaction. Retrieved from http://modernistcuisine.com/2013/03/the-maillard-reaction/

Schulze,E. (April 2017) What is Maillard Reaction. Retrieved from http://www.seriouseats.com/2017/04/what-is-maillard-reaction-cooking-science.html

Wikipedia (n.d) Maillard Reaction. Retrieved from https://en.wikipedia.org/wiki/Maillard_reaction#Foods_and_products_with_Maillard_reactions

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