Active antibacterial food coatings based on blends of succinyl chitosan and triazole betaine chitosan derivatives

In this work, we demonstrate that highly antibacterially active triazole betaine chitosan (TBC) component can be incorporated into succinyl chitosan sodium salt (SC-Na) matrix by simple mixing to afford quite compact and uniform films. Blending of SC-Na and TBC improves tensile strength and simultaneously diminishes oxygen and water vapor permeability of the formed blend films. These improvements are most pronounced for blend films with SC-Na:TBC ratio 1:1. Test applications of the blend films as food coatings for bananas reduced their weight loss, vitamin C loss, and respiration rate, and this resulted in a significantly extended shelf life of the coated bananas. Moreover, the prepared blend films are non-toxic since they are composed of non-toxic SC-Na and TBC. Finally, we demonstrate that the incorporation of TBC into the SC-Na matrix dramatically enhances the antibacterial activity of the blend coatings with a high TBC fraction (50 % and higher) and these results are among the best reported in the field of antibacterial films so far.