Improving the antifungal activity of clove essential oil encapsulated by chitosan nanoparticles

•Clove essential oil was loaded into chitosan nanoparticles by emulsion-ionic gelation.•Two chitosan and four clove oil concentrations were used for nanoparticle synthesis.•FTIR spectroscopy evidenced the presence of clove oil in optimum nanoparticles.•The optimum nanoparticles showed spherical shapes with the size of around 100 nm.•The antifungal activity of encapsulated oil improved due to controlled release of oil. Encapsulation of clove essential oil (CEO) by chitosan nanoparticles (ChNPs) was performed, using an emulsion-ionic gelation technique to improve the antifungal efficacy of CEO. The mass ratios of chitosan (Ch) to tripolyphosphate (TPP), 1:1, for unloaded ChNPs and 1:1:1 for Ch to TPP to CEO, for CEO-loaded ChNPs (CEO-ChNPs), were selected as optimum formulations based on dynamic light scattering and ultraviolet-visible spectroscopy. The presence of CEO in optimum CEO-ChNPs, was evidenced by Fourier transform infrared spectroscopy. Particle size distribution, of around 40 and 100 nm for the most optimum unloaded and oil-loaded ChNPs, was obtained by field emission-scanning electron microscopy. In vitro release studies of CEO-ChNPs revealed a controlled release during 56 days. The nano-encapsulated CEO demonstrated a superior performance against Aspergillus niger, isolated from spoiled pomegranate, compared with ChNPs and free oil. Therefore, this study revealed that CEO-ChNPs can be used as a promising natural fungicide in agriculture and food industry.