If you’ve ever made any potato dish you might have had both great successes and failures with the exact same recipe. In some cases the fries just turn out perfect, in other cases they brown way too quick and burn.
Chances are that your recipe is perfectly fine, but that you’re using a different type of potato variety or potatoes that were stored differently. These can result in huge differences between the outcomes of your potato dish. That’s the beauty (and challenge) of using natural products. They’re never identical and all have their own properties. For potatoes, the amount of browning and its texture are the most important variables. There are a few mechanisms at play here:
Sugar & the Maillard reaction
One of the main browning mechanisms that occurs when you prepare your potato is that famous Maillard reaction. This is a very common reaction between reducing sugars (e.g. glucose, lactose) and proteins in food. There are several ways to control the Maillard reaction. By controlling the amount of sugar and proteins you can get more of the reaction going on. More sugars will lead to more browning and as we’ll discuss further down, there are a lot of ways to control the sugar content of a potato, whereas you’re more limited when it comes to the proteins.
The other controlling factor is the temperature and time. At higher temperatures the reaction goes a lot faster, thus it browns more quickly. At lower temperatures it goes more slowly, which will give you a chance to cook the inside well (as you do when making french fries)!
When a potato contains more sugar it tends to brown more quickly. The same goes for cakes, bread and other baked goods. The amount and type of protein present tends to impact browning as well, however, the role of sugar seems to be a lot more important, especially for potatoes. Therefore, if you want your fry to brown well, you should get a slightly higher sugar content than if you’re looking for a more yellow/pale potato colour. That said, you never want the sugar content to be too high. This will result in a burned potato before you even get a chance to cook the inside.
Browning can also be caused by a reaction caused by enzymes. Enzymes are proteins and will be broken down by the extreme heat; however, they can result in browning at the start. A good proof for this mechanism being important is that blanching potatoes (quickly boiling them before frying) prevents a lot of browning of fries! Since enzymes are broken down by heat, this heat treatment will prevent any of this browning.
Crisp chips with browned skin.
(Photos courtesy of foodnetwork.com)
These potatoes apparently don’t have that much sugar seeing how yellow they are after frying.
(Photos courtesy of www.foodpower.info)
Articles courtesy of https://foodcrumbles.com/why-some-potato-chips-brown-and-others-dont-potato-science/