Are they available?
I”m not sure.
I looked at the underlying study:
https://www.mdpi.com/2072-6643/16/20/3550
It looks like it was sponsored by Viscofan, which is a meat casing company. (Casings are often made from collagen.)
The description (chocolate bar with chunks) sounds like a commercial product that is at or near production.
But I didn’t see any end-consumer products for sale on the Viscofan. Did get a deal on 10,000 hotdog casings, though. (j/k).
Coming soon, I suspect.
As a protein and collagen guy (I am senior class power lifter), I’ve noticed just normal collagen and really most protein really “sticks to the ribs” as grandpa used to say and is very sating. So I suspect there is more to this product than just taking up space in your stomach.