Structure-function relationships in chitosan films containing ZIF-8-confined Ligusticum jeholense essential oil:...

Postharvest apple ring rot caused by Botryosphaeria dothidea remains difficult to control due to the poor aqueous compatibility and rapid volatilization of volatile essential oils. We engineered a chitosan (CS) film embedding Ligusticum jeholense essential oil within zeolitic imidazolate framework-8 (LEO@ZIF-8) to achieve sustained antifungal release. TEM/SEM, FT-IR, XRD, and XPS confirmed high LEO loading (65.5%) and encapsulation efficiency. LEO@ZIF-8 demonstrated pH-responsive release, with 82.6% at pH 5.0. In vitro, LEO@ZIF-8 inhibited B. dothidea more effectively than free LEO (64.6% vs. 50.6% at 62.5 nL/mL). On detached apples, LEO@ZIF-8/CS film improved hydrophobicity, enhanced microstructural homogeneity, and delayed lesion formation. It reduced weight and firmness loss, retained soluble solids, and decreased oxidative stress markers (DPPH, SOD, MDA). ZIF-8 stabilized LEO and enabled controlled release, while CS provided antimicrobial support, demonstrating LEO@ZIF-8/CS as an effective active-packaging solution for long-term fruit preservation, offering a sustainable approach to postharvest disease control.