Enhanced antifungal activity of Origanum vulgare L. essential oil through Eudragit® S100–based nanoencapsulation

Postharvest fungal decay remains a major constraint to fruit quality and shelf life, driving the search for effective and sustainable alternatives to synthetic fungicides. This study aimed to develop Eudragit® S100 based nanocapsules containing Origanum vulgare L. essential oil (OVEO) and to evaluate their antifungal efficacy, with an initial in vitro screening against Botrytis cinerea , Colletotrichum fructicola , Colletotrichum gloeosporioides , and Penicillium digitatum , followed by targeted in vivo assessment against C. gloeosporioides , the causal agent of apple anthracnose. Seven essential oils were first screened for inhibition of conidial germination. OVEO exhibited the highest activity, completely inhibiting germination of all four pathogens at concentrations ≥ 0.05 % (v/v), and was therefore selected for nanoencapsulation. OVEO nanocapsules were prepared by interfacial deposition using Eudragit® S100, achieving an encapsulation efficiency of 90.7 % and a loading capacity of 81.2 %, with a mean hydrodynamic diameter of 229 nm. In in vitro assays, nanoencapsulated OVEO (OVEO–NC–5) fully suppressed conidial germination of all tested fungi at 0.025 % (v/v) after 48 h, whereas free OVEO showed reduced efficacy at the same concentration. In in vivo trials on apples inoculated with C. gloeosporioides , OVEO–NC–5 reduced lesion diameter by 62 % at 0.025 % (v/v) after 21 d, while complete inhibition of symptom development was achieved at 0.05 % (v/v). These results demonstrate that Eudragit® S100 nanoencapsulation significantly enhances the stability, efficacy, and practical applicability of O . vulgare L. essential oil, representing a promising strategy for sustainable postharvest disease control.