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

•Triazole betaine chitosan and succinyl-Na chitosan blending gives new food coating.•The coating is taste-, color-, and odorless.•The coating has excellent barrier, mechanical and outstanding antibacterial properties.•The coating significantly improves shelf-life of bananas. 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.