My Potatoes Are Slightly Green and Taste Bitter, Why?

Q:

Hello! Tonight we fried some Idaho baking potatoes as chips. When I was peeling them, I noticed some of the ones we used had green under the skin and the eyes had started to sprout. Unfortunately, the potatoes weren't properly stored, but not much I could do about that other than peel and prep for use as chips. When we went to eat them, we noticed the chips had a bitter taste to them. We used new, unsealed canola oil in a dutch oven configured as a deep fryer. The temperature was held between 320 and 360. and chips were cooked for about 5-7 minutes. The chips were not burned, had been rinsed, soaked for an hour+, and dried before cooking. Any suggestions as to why they were bitter? I know about solanine in the skin but figured peeling would remove the bitterness. Does the solanine permeate the potato? 

A:

There are numerous studies that discuss potato skin greening; their cause and effect on potatoes, and the resulting bitter flavor that results if consumed in whole or part – including how some solanine can permeate the potato. While you can safely prepare and consume slightly-green skinned potatoes by peeling away any affected surfaces  – this could impart some bitter, off-flavors. When it comes to food safety it’s always best to discard any product that you suspect may be questionable. Click below for more information on this topic and one on proper potato storage, along with a few other fact sheets.  

Idaho® Potato Best Practices - HERE

Greening - HERE

Potatoes and Weight loss - HERE

Nutrition in Skin vs Flesh - HERE

Carbohydrate - HERE

Idaho® Potatoes vs Sweet Potatoes - HERE

Glycemic Index - HERE