Mushroom-Derived Chitosan as an Alternative Feedstock for Active Packaging Films: Performance and Biodegradation

We report the successful fabrication and application of a vanillin cross-linked chitosan film for use as an active packaging material using Agaricus bisporus (white button mushroom) as an alternative feedstock for chitosan. Utilizing an alkali extraction method, chitosan was obtained with a degree of deacetylation (DDA) of 85%. The mushroom-derived chitosan was combined with vanillin and gallic acid to form composite films by casting. The thin films were analyzed using a suite of analytical techniques including Fourier Transform Infrared Spectroscopy (FTIR), Thermogravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC), Scanning Electron Microscopy (SEM), UV–visible spectroscopy (UV–vis), and water vapor permeability testing. The chitosan films displayed 100% UV-blocking and mechanical and thermal properties similar to crustacean-derivatives with values of 10.4 ± 0.8 MPa for tensile strength and a glass transition temperature of 224.8 °C. The controlled release of gallic acid into a lipophilic food simulant was achieved and tested over 336 h. Antioxidant and antimicrobial testing confirmed the potent effects of gallic acid on the prevention of bacterial growth and the quenching of free radicals. Chitosan films were effective against Escherichia coli and Staphylococcus aureus and quenched 95.5 ± 0.1% of 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals. The results presented provide a promising starting point for the development of a degradable active packaging material from mushroom feedstocks.