Baked Sweet Potatoes Have BROWN In Them

I notice that when I bake sweet potatoes, there are occasional large areas of brown in the edible portion. One cannot tell that the inside is brown from the outside of the tuber before cooked. I usually eat the orange colored flesh sweet potatoes and always discard the large brown sections. Many times the sweet potatoes have brown 'strings' running on the outside of the edible part but I eat this part but this is not of any concern.

However, back to the large section of brown that runs throughout the edible portion: Is this brown ok to eat? Does it mean that they are ruined? Should I discard it the whole potato?

I am referring to both home-grown and store-bought sweet potatoes.

Thanks for the responses.