Enhanced properties of chitosan-PVA nanocomposite films with lemongrass oil microcapsules

Abstract

The need for sustainable antimicrobial packaging has driven research into biodegradable materials that extend shelf life and reduce reliance on synthetic additives. This study developed biocomposite films using chitosan (CS) and polyvinyl alcohol (PVA), enhanced with lemongrass essential oil (LGEO) and cellulose nanocrystals (CNCs). Different concentrations of LGEO (5 %-20 % w/w) and CNCs (0.5 %-1.5 % w/w) were systematically evaluated for their effects on the films' mechanical, antimicrobial, and physicochemical properties. The results showed that incorporating CNCs and LGEO significantly improved antimicrobial efficacy and hydrophobicity, as reflected in reduced water vapor permeability and increased water contact angles. Films with higher CNC concentrations (1.5 %) exhibited reduced water solubility and swelling due to enhanced crosslinking and crystallinity, while lower concentrations resulted in higher values. Over time, all samples displayed weight loss, pH increases, and reduced moisture, titratable acidity, and firmness, alongside color changes indicated by a decline in the L* index and an increase in the a* index. Optimized films outperformed cellophane in maintaining physicochemical stability and reducing microbial spoilage of cherry tomatoes during storage. These findings underscore the potential of CNC- and LGEO-enriched CS/PVA biocomposite films as eco-friendly, effective packaging solutions for extending the shelf life of perishable foods while addressing plastic waste issues.