Here is an interesting article on the development by some researchers in Spain of an Aloe vera gel as a natural preservative. They tested it on fruit and I wonder if it would work on chocolate as well? Apparently it works as a natural barrier to moisture and oxygen, the two most important items for chocolate. Plus it's natural and safe which could be important selling points. It might take a while though until this is available commercially (if at all).
http://www.foodnavigator.com/news-by...vera-developed