Triple-function chitosan-based film for pork and shrimp packaging.

A film simultaneously with colorimetric, fluorescent and active functions was engineered using chitosan (CS) and polyvinyl alcohol (PVA) as the film matrix and curcumin-β-cyclodextrin complex (Cur-β-CD) as the indicator for freshness monitoring and maintaining of pork and shrimp. In addition to the efficacy of prolonging shelf life, the film's color could change from yellow to orange with ΔE > 5 and its fluorescence intensity could decrease during storage. The incorporation of PVA significantly enhanced the mechanical properties of CS film with tensile strength of 31.80 MPa and elongation at break of 127.22 %. The Cur-β-CD improved the antioxidant and antibacterial properties, water contact angle (from 86.3° to 111.2°), water vapor permeability (from 3.28 × 10 g (m s Pa) to 0.42 × 10 g (m s Pa)) and mechanical properties of CS/PVA film. These results show the potential of the film as promising alternatives for intelligent and active food packaging.