Molecular guardians: Unveiling chitosan film defense through analytical microscopy

Abstract

In response to growing environmental concerns about plastic packaging, this study examines biopolymer-based alternatives, focusing on the development and performance of chitosan-based films enhanced with polyvinyl alcohol (PVA), polyethene glycol (PEG), glycerol and essential oils as eco-friendly packaging solutions. Using the solvent casting method, chitosan films were prepared with incorporated essential oils to enhance their functional characteristics. FTIR analysis confirmed the successful fabrication of the films by identifying functional groups such as -OH, N-H, C=O, C≡N, C-Cl, C-Br and metal-O bonds. SEM analysis revealed smooth surfaces with minimal residues, indicating partial uniformity. Antimicrobial testing revealed that sample S₁ exhibited concentration-dependent inhibition, whereas sample S₂ demonstrated strong, broad-spectrum activity against Staphylococcus aureus and Escherichia coli at higher concentrations. Antioxidant activity, evaluated using the DPPH assay, revealed that at 10 µL of sample S₂, 76.22 % inhibition was achieved and sample S₁ showed 75.40 %, with effectiveness declining at higher concentrations. The findings underscore the promise of chitosan-essential oil films as multifunctional packaging materials with both antibacterial and antioxidant properties. In horticultural applications, these biofilms present a sustainable alternative to traditional plastics, contributing to improved product quality and extended shelf life during postharvest processes and marketing.