Clove essential oil-loaded chitosan nanoparticles: Development, characterization and antifungal activity

Clove essential oil (CEO), rich in eugenol, offers strong natural antimicrobial properties as an alternative to synthetic preservatives. This study aimed to encapsulate clove essential oil (CEO) into chitosan using ionic gelation, characterize the physical and chemical properties of the resulting nanoparticles, and evaluate their antifungal efficacy against Aspergillus niger. The nano-encapsulated CEO was characterized by using various techniques such as scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and X-ray Diffraction (XRD) confirmed the formation of spherical nanoparticles and the successful incorporation of CEO functional groups within the matrix. Initial assessments confirmed the dose-dependent antifungal activity of free CEO. Agar diffusion assays against A. niger demonstrated a substantial increase in antifungal efficacy, with inhibition zones increasing by approximately 186% as the concentration of clove essential oil (CEO) from 5% to 100%. The antifungal activity of the encapsulated CEO also increased with higher loading concentrations representing an increase of approximately 165% at 1:2 (EO:CS) ratio compared to the 1:1 (EO:CS) ratio. These findings demonstrate that CEO encapsulated in chitosan nanoparticles significantly enhances antifungal activity and provides a promising strategy for natural food preservation by extending shelf life and reducing fungal spoilage.