Exploring the Potential of Essential Oils as Bio-Additives to Enhance the UV Protection and Antibacterial Properties of Chitosan Films

This study aims to investigate the potential role of eucalyptus and thyme essential oils (EOs) as bio-additives in enhancing the characteristics of chitosan with varying molecular weights (MW). A hybrid formulation of these EOs was incorporated into high- and low-MW chitosan. Based on morphological analysis, high-MW chitosan significantly enhanced the dispersion quality of the EOs. The UV barrier property for low- and high-MW chitosan samples loaded with the EO hybrid was observed at 6.4% and 46.8% at 400 nm, indicating the significant impact of chitosan's molecular weight and EO dispersion quality on the UV protection behavior. The toughness was significantly improved by adding the EO hybrid to the low- and high-MW chitosan films, resulting in 104% and 270% enhancements, respectively. The water-absorbing capacity results revealed that the high-MW chitosan incorporated with the EO hybrid exhibits superior water barrier properties, making it more promising for packaging applications. Although molecular weight did not affect the antibacterial activity of pure chitosan films, it had a significant impact on the antibacterial properties of EO-loaded chitosan films. The findings highlight the impressive potential of EO-based bio-additives for biodegradable food packaging, suggesting a promising future for sustainable solutions in the industry.