Antifungal activity and sensory analyses of chitosan aromatized with essential oils for the protection of fresh oranges and apples

Postharvest diseases caused by fungal and oomycete pathogens represent a major threat to fruit preservation, especially in the absence of effective and sustainable alternatives to synthetic fungicides. This study evaluated the antimicrobial potential of ten chitosan-based formulations, each containing a different essential oil (EO), for the control of a broad spectrum of fungal and oomycete plant pathogens. In vitro assays, including agar diffusion, MIC/MFC determination, and volatile organic compound (VOC) inhibition tests, identified the two formulations ID-F-03 (containing Origanum vulgare EO) and ID-F-06 (containing Cinnamomum verum EO) as the most effectives. These formulations were further characterized by GC–MS analysis and tested in vivo on artificially inoculated apples and oranges. The results showed that both formulations significantly reduced disease incidence in both fruit, with ID-F-03 being particularly effective in limiting bitter rot development in apples and ID-F-06 in reducing green mold symptoms in oranges. GC–MS analysis identified carvacrol (ID-F-03) and ( E )-cinnamaldehyde/eugenol (ID-F-06) as the major volatiles. Sensory evaluation indicated a good overall acceptability of treated fruit, with formulation–fruit combinations showing specific sensory responses; specifically, ID‑F‑06 maintained higher hedonic scores in apples, whereas ID‑F‑03 was better accepted in oranges. The study confirms the potential of chitosan–EO combinations as promising tools for the management of postharvest diseases of apples and oranges, with their application as active components in packaging materials offering a viable strategy to balance antimicrobial efficacy and sensory quality. • Chitosan–EO formulations inhibited multiple fungal and oomycete pathogens in vitro. • Chitosan-based formulations with O. vulgare or C. verum EOs showed strongest activity. • Apple bitter rot and orange green mold were markedly reduced in vivo. • GC–MS identified major volatiles: carvacrol; ( E )-cinnamaldehyde; eugenol. • Sensory analysis showed fruit- and formulation-dependent flavor changes.