Development of antimicrobial films based on chitosan-polyvinyl alcohol blend enriched with ethyl lauroyl arginate (LAE) for food packaging applications

The main aim of this study was to characterize microstructural, physical, optical, mechanical, water barrier and antimicrobial properties of chitosan-polyvinyl alcohol blend films (CS-PVA) enriched with ethyl lauroyl arginate (LAE) (1–10% w/v) for food packaging applications. The film microstructure was determined by scanning electron microscopy. Active films containing 10% LAE showed cracks on the surface with irregular shape in the cross-section indicating a weaker cohesion of the CS-PVA polymer blend at high LAE concentrations. The possible interaction of CS-PVA blend film with incorporated LAE was also investigated using Fourier-transform infrared (FT-IR) spectroscopy in the attenuated total reflection (ATR) mode. FT-IR/ATR spectra showed a low molecular interaction between the CS-PVA and LAE up to 2.5% while for films containing 5 and 10% LAE such interactions between the functional groups of the CS-PVA matrix and LAE have been detected. The active films were transparent and showed barrier properties against UV and visible light. The incorporation of LAE into the CS-PVA increased the thickness, water solubility, water vapor permeability, and the b* and ΔE* values, while it decreased mechanical properties and transparency (p < 0.05). Active films inhibited the growth of four major food bacterial pathogens including Campylobacter jejuni, Escherichia coli, Listeria monocytogenes and Salmonella typhimurium. Particularly, films containing 5 and 10% LAE were the most effective (p < 0.05). Overall, the characterization of functional properties revealed that CS-PVA blend film incorporated with LAE could be used as an environmentally friendly antimicrobial packaging material to extend the shelf life of food products.