Development of multifunctional packaging films based on arginine-modified chitosan/gelatin matrix and betacyanins from weed amaranth (A. hybridus)

Active and intelligent films with antioxidant, antimicrobial, and pH-responsive properties were developed by incorporating betacyanins-rich weed amaranth (A. hybridus) extract (AE) into chitosan/gelatin (Cs/Gn) and arginine-modified chitosan/gelatin (MCs/Gn) blend films. The microstructures, physical and functional properties of Cs/Gn, MCs/Gn, Cs/Gn-AE, and MCs/Gn-AE films were compared. Results showed the addition of AE into MCs/Gn film produced a compact inner microstructure through H-bonding and electrostatic interactions. Meanwhile, AE remarkably changed the colors of the film under alkaline pH mediums. However, AE significantly reduced the water vapor permeability of the films. By comparing different films, MCs/Gn-AE film presented the best UV-vis light and barrier ability as well as the highest mechanical strength. Moreover, MCs/Gn and MCs/Gn-AE films showed stronger microbial growth inhibition than Cs/Gn and Cs/Gn-AE films. Cs/Gn-AE and MCs/Gn-AE films possessed more potent free radical scavenging activity than Cs/Gn and MCs/Gn. Notably, MCs/Gn-AE film is suitable to monitor fish freshness and could be used as novel multifunctional packaging in the seafood industry.