Potatoes-why do they get black on the edges after boiling?

[JustACountryMusicGirlInCowboyBoots]

I can't seem to find an answer online.

If I parboil then drain and leave in the pan whilst the oil finishes heating to roast them I find the edges start to turn black in places. There's nothing on them when they go in the pan. The pan is not non-stick, just a regular pan.

Why does this happen and how can I prevent it please?

Weird. Has never happened to my spuds

Never seen that.. maybe just make sure the oil is ready so you can dump em in no waiting

If you run them under cold water quickly so they don’t sit in the air it doesn’t seem to happen as much, huge reaction when you pop them in hot oil though.
I try to stick the tray of oil in the oven before I drain the spuds. I drain and shake, pop the tray of oil onto the still hot ring then tip the spuds in asap.

It's literally just oxidation

Yes it's a reaction to the air. Need to time your parboiling/oil heating a bit better 😉

I've never had potatoes turn black. Is it to do with how long you are leaving them in the pan? I do tend have the oil hot and ready and also dredge the potatoes with seasoned flour pretty much as soon as they are dry.

It could also be the type of potatoes you use - for me King Edward's are the only potato for roasties. If I can't get King Edward's I don't do roast potatoes.

If you par boil them a bit longer then they don’t do this.

Thank you!
I've used various types but most recently Maris pipers which have been simultaneously falling apart yet not cooked.

How long are you boiling them, my oil/fat is hot enough by the time they are boiled to put straight into the pan.

They're better for roast or chips.

Oxidation, just like an apple turning brown.