I hope you're all willing to continue the conversation because I recently encountered this thread and I've been on mission to create a bioplastic bait for a few months now.
Although I'm still in the experimental stage, I've concluded that gelatin (visual of plug, below) is not suitable because it's melting point is too low - can't be subjected to the summer heat; and the gelatin continues to expand when submerged in water. Otherwise, gelatin and glycerin produces the perfect flexible, soft plastic for baits.
Lately, I'm working on a recipe that expands upon the use of agar-agar and glycerin (bait shapes for testing, below). Soon, I'll be introducing Locust Bean Gum (LBG), Xanthan Gum(XG), Guar Gum (GG) and Sorbitol in effort to reduce weeping (water loss), reduce the brittle nature of Agar, and create a stronger, firmer, rubbery material. I've not been able to narrow down just how much of LBG, XG, GG or Sorbitol to start with.
Does anyone have knowledge or experience with LBG, XG, GG or Sorbitol?