Innovative Water-Insoluble Edible Film Based on Biocatalytic Crosslink of Gelatin Rich in Glutamine

Gelatin is a promising candidate for making bioplastic film; however, the water soluble property has limited its applications. Here, we have successfully fabricated a water-insoluble gelatin film with the assistance of biocatalysis. This innovative gelatin film could retain its original shape at ambient temperature (30 °C) or even in boiling water. Type E gelatin could form more covalent crosslinks when compared to that of conventional ones with the same amount of microbial transglutaminase (MTGase), and it exhibits obvious changes in terms of molecular weight, network structure, and mechanical strength. This work could provide a strategy for fabricating water-insoluble gelatin film and open routes for the development of bioplastic film using gelatin.