Enhanced strength, antioxidant and barrier properties of chitosan-based film by bentonite and lignosulfonate

The application of chitosan (CS) film in active food packaging fields is greatly limited by their poor strength, antioxidant and barrier properties. Two nanoparticles, lignosulfonate (SLS) and bentonite (BT), were used together to enhance the food packaging properties of CS composite films in this work. A dense and robust multifunctional bio -based nanocomposite film with a pearl -like structure was successfully prepared. Results indicated that the introduction of SLS substantially better the strength, antioxidant, and UV-shielding capacities of CS composite film. The maximum tensile strength of the obtained nanocomposite film (SLS/BT/CS) reached 1.9 times of pure CS film. The SLS gave the composite film an excellent UV-shielding property (between 6.18-0.14% (TUVA) and 0.32-0.06% (TUVB) at 10-40 wt% SLS). The total phenolic hydroxyl group content of the composite film was significantly increased after adding SLS, and the DPPH & sdot; scavenging ability of SLS/BT/CS film was 5 times better than that of BT/CS film. The addition of BT bent the water vapor transport path in the film and created a hydrophobic surface, which in turn led to a significantly better water vapor barrier performance of SLS/ BT/CS than pure CS films. The results of this work showed the great application potential of SLS/BT/CS nanocomposite film in the food packaging fields.