I grew up with them in the back yard. Low in calories, lots of flavor, nutrients and fiber. Some don't like the tough skins but that's where a lot of the nutrients are. Do you like them?
I had to Google scuppernongs. I guessed it must have been a grape since you also asked about muscadines. No, I don't eat any. I've never even seen them in our supermarkets up here.
We have those around here, and sometimes people bring them to the farmers market to sell. I tried some and they tasted great; but the skin WAS tough. They were expensive or I would have bought more, but we just got enough to taste them and see. I think the ones I tried were muscadine, but I don’t remember for sure.
I will have to watch and see if they have some again this fall. I have never seen them in the regular grocery stores, just at the farmers market.
They are a native U. S. fruit that only grows well in the southeast and can be deep, dark blue or bronze in color. They make delicious wine and jelly and are so expensive because so few are grown and the season is short. My local supermarket had them. Also seen at Aldi.
Muscadines grow wild in the woods here. I like them, just to eat off the vine. I pop the inside into my mouth and throw the tough skin away. Don't chew the center either (it's sour). Commercial ones are probably a lot better and bigger. Trouble is the deer usually get any within reaching distance first.
I think scuppernongs grow wild too, but I've never seen any here or tried them.