Why do potatoes discolour when peeled?
I've noticed that potatoes will discolour when they're peeled; however, if they are submerged in water, or boiled and drained, they're fine (at least for comparable periods of time). Why is this?
Best Answer
Short answer: Potatoes oxidize.
Slightly longer answer: Potatoes contain an enzyme called polyphenol oxidase (the same enzyme responsible for browning in apples), which when exposed to oxygen in the air turns that brown/grey color. That process is called oxidizing. Because oxygen is required to, well, oxidize, any means of preventing the air from coming into contact will keep them from discoloring. Submerging in water is just an easy and convenient way of doing that. Also, polyphenol oxidase is neutralized during cooking, so cooking the potatoes immediately prevents the discoloration.
Pictures about "Why do potatoes discolour when peeled?"
Quick Answer about "Why do potatoes discolour when peeled?"
As soon as you leave out peeled or cut potatoes, the oxidation process begins and the potatoes turn brown. Oxidation is a chemical reaction between the starches and sugars in the potato and the air that does not impact the edibility of the potato but does change its color.How do I stop potatoes going brown when peeled?
Besides vitamin C, you could use vinegar or lemon juice, both of which are acidic enough to do the trick. Combine both these methods by soaking the potatoes in a bowl of cold water mixed with vinegar or lemon juice. Vacuum pack the peeled or grated potatoes to prevent air from causing the discolorization.Can you eat potatoes that have turned brown after peeling?
This process, which is called oxidation, happens because potatoes are a naturally starchy vegetable. And when exposed to oxygen, starches turn gray, brown, or even black. An oxidized potato is completely safe to eat, the process doesn't affect the flavor or texture of the vegetable.Are discolored potatoes safe to eat?
If the cooked potatoes were not left out overnight, unrefrigerated then they will be okay to eat. They will be pretty unattractive to the eater but will taste fine. If they were left out, then because of the dairy (butter) they would not be safe to eat.Why are my peeled potatoes turning red?
According to The Kitchn, it's simply a chemical reaction. When you cut into a potato, you're also cutting into its cell walls. In doing so, you're exposing the potato's phenols and enzymes to oxygen in the air, resulting in a chemical reaction that manifests itself in the form of a pink hue.How to Prevent Potatoes From Discoloration | Real Simple
Sources: Stack Exchange - This article follows the attribution requirements of Stack Exchange and is licensed under CC BY-SA 3.0.
Images: Artem Podrez, Matthias Zomer, Artem Podrez, Artem Podrez