Enhanced ultraviolet barrier, antioxidant and antibacterial properties of chitosan-based films incorporated with caffeic acid–grafted inulin for strawberry preservation

Active packaging films fabricated from chitosan have recently emerged as a promising candidate for food packaging and preservation. In this study, caffeic acid-grafted inulin (CA-g-In) was successfully prepared as a bioactive additive, and chitosan-based composite films incorporated with different amounts of CA-g-In were developed. The effects of CA-g-In incorporation in modulating the physical, antioxidant and antibacterial functionalities of the films were also explored. The incorporation of CA-g-In significantly increased the tensile strength, elongation at break and opacity of the films. Moreover, the composite films exhibited excellent ultraviolet barrier power, 2,2-diphenyl-1-picrylhydrazyl radical scavenging ability, reducing capacity and antibacterial activity, which were proportional to the CA-g-In content. Finally, the composite films were evaluated for their practical use in strawberry preservation, achieving reduced strawberry decay and extending strawberry shelf life. The findings indicated that chitosan-based films enriched with suitable content of CA-g-In could serve as effective and eco-friendly packaging materials for food preservation.