Evaluation of different characteristics and bioactivities of chitosan-based films incorporating Eugenia caryophyllus and Cinnamomum zeylanicum essential oils

Abstract

Nowadays, using biodegradable and active packaging as an alternative to oil-based plastics become a trend. Thus, we aimed in this study to develop and generally evaluate chitosan-based films (CH-film) incorporating C. zeylanicum and E. caryophyllus essential oils (EOs) for eventual utilization as food active-packaging. Experimental data revealed that the film thickness and opacity increased from 2.2- to 6-folds, and from 2.6- to 4.5-folds respectively, following the addition of EOs. Moreover, the treated materials revealed a significant drop in hydrophobicity, elongation at break, moisture content, and swelling degree, especially in the case of cinnamon EO treatment. A correlation was observed between the antioxidant property and total phenolic content. The DPPH inhibitory behavior and release of phenolic compounds of the treated CH-films increased over time, reaching third-day values higher than 15 mg gallic acid/g sample, and 80% of DPPH inhibition, respectively. Finally, the introduction of clove and cinnamon EOs significantly promotes the antibacterial and antibiofilm properties of the material against Escherichia coli, Enterococcus hirae, Staphylococcus aureus, and Pseudomonas aeruginosa. Biofilm inhibition values ranged from 69.76 to 96.97% depending on the bacterial species.These promising findings encourage the potential utilization of CH-films supplemented with EOs such as cinnamon and clove EOs to replace plastic-based films as packaging, especially in the agri-food industry.