Preparation of a Polycaprolactone/Chitosan/Graphene Oxide Composite Film and Application in Blueberry Packaging

A biodegradable composite film active packaging material was prepared via solution casting technology using the biodegradable polycaprolactone (PCL) as the film matrix, chitosan (CS) as a cationic basic polysaccharide, a widely available and renewable raw material, and the antimicrobial graphene oxide (GO) as an additive. The optimal conditions for preparing the CS-GO-PCL composite film were screened using single-factor methods with the film tensile strength being used as the test index. The results showed that the maximum tensile strength of the CS-GO-PCL composite film prepared using 5% w/v PCL-acetate solution as the matrix, 18 wt% CS, and 5 wt% GO, a blending time of 1.8 h, and a drying temperature of 57 degrees C was 8.56 +/- 0.14 MPa. The structure of PCL composite film containing both CS and GO was denser and more thermally stable than the film prepared using PCL alone. In addition, the hydrophobicity, swelling rate, and water vapor transmission rate were lower for the composite film. The composite film was applied to preserve the freshness of blueberries, and the antioxidant and antimicrobial properties of the composite film were found to be superior to those of the PCL film.