Self-assembly of tea polyphenol onto the high strength chitosan film fabricated via a new way to enhance the antioxidant and antibacterial activity for meat preservation

Chitosan (CS) films traditionally prepared from acid have poor mechanical properties, thus limiting their application as packaging materials. In this study, high strength chitosan-tea polyphenol (CS-TP) films were fabricated via a new way. Firstly, high strength CS film was prepared by regeneration of CS dissolved in alkali from hot water, then TP was incorporated into CS film through the one step self-assembly method. It was found that large amount of TP was adsorbed onto CS film due to the strong hydrogen bonding and hydrophobic interaction between CS and TP confirmed by results of adsorption tests, FTIR and XRD. Moreover, the mechanical, anti-UV, antibacterial and anti-oxidant properties of the CS-TP films gradually enhanced with increasing content of TP. The water vapor permeability rate of CS-TP films slightly increased with increasing content of TP. Pork perseveration results indicated that the CS-TP films lowered the pH, slowed the growth of bacterial and change of color, decreased the lipid oxidation products content of fresh pork compared with CS film or the control sample, thus prolonging the shelf life of fresh pork for 2 days. Therefore, this study proposed a new strategy for preparing high strength muti-functional CS-TP films as food packaging materials.