Preparation and characterization of chitosan/bacterial cellulose composite biodegradable films combined with curcumin and its application on preservation of strawberries

We provided in detail a simple and environmentally-friendly method to prepare a biodegradable composite film using chitosan (CS) and bacterial cellulose (BC) with excellent dispersion. CS was grafted onto BC by Schiff base reaction firstly, and then obtained the nano-sized fibrils by ultrasonic dispersion process (CS-OBC). Different concentrations of curcumin (Cur, 0 %, 0.1 %, 0.3 %, 0.5 %, and 0.7 %, w/v) were incorporated into CS-OBC composite films prepared with optimal film-forming parameters. Mechanical and antioxidant properties, including moisture content, water solubility, and contact angles, were evaluated to determine the effects of Cur addition on the composite films (CS-OBC-Cur). It was found that Cur addition increased the hydrophobicity and oxygen permeability of the film, and that the CS-OBC-0.5%Cur active film exhibited excellent barrier properties, hydrophobicity, and mechanical properties. In addition, polyphenol release was retarded when the active film was in a simulated fat system. The film showed superior preservation of strawberries compared with ordinary PE film and significantly slowed the oxidation of edible oils. These results suggest that CS-OBC-Cur films are a promising food packaging material.