Fabrication and application of biodegradable packaging film utilizing chitosan extracted from catla fish scales

Abstract

A biodegradable packaging film was developed using chitosan extracted from catla fish scales, aiming to provide a sustainable alternative to conventional plastic packaging. Chitosan extraction was carried out using a microwave-assisted method, yielding 83.87% after deacetylation. The extracted chitosan was characterized using FTIR, XRD, SEM, and DSC analyses and confirming its semi-crystalline nature with a crystallinity index of 60.76%. SEM imaging revealed a rough and dense surface morphology, which is beneficial for barrier properties. The water vapor permeability (WVP), tensile strength, and elongation at break were evaluated, showing that pure chitosan film exhibited a higher WVP rate than composite chitosan films. The mechanical properties improved with increasing glycerol concentration. The degradation study revealed that the extracted chitosan films had degradation rates of 55.64% (film1), 42.08% (film 2), and 48.64% (commercial chitosan), confirming their biodegradable nature. Antimicrobial assays showed significant inhibition of Staphylococcus aureus (31 mm, 22 mm) and Escherichia coli (19 mm, 16 mm), demonstrating the potential of extracted chitosan for food preservation. Furthermore, the application of the chitosan-based film for grape storage resulted in reduced weight loss, enhanced firmness, and prolonged shelf life. The findings highlight that chitosan extracted from catla fish scales can be a promising alternative for eco-friendly packaging, reducing environmental impact while ensuring food safety.