I remember when I was a kid back in the 80s, they had a brief show where kids could show off their inventions and this one girl came up with a type of edible tape you could use to do things like hold burritos together. I still think that's genius. Of course, it never became an actual product.
I have no idea if they still do it, but a decade or so ago it was all over the internet that a Brazilian fast food company had started using edible wrappers and made a marketing stunt out of it. The chain was apparently "Bob's".