Engineered antifungal nanofibers for extending strawberry shelf life

Postharvest losses of fresh strawberries remain a major challenge due to their high susceptibility to fungal decay and rapid quality deterioration. This study aimed to develop polycaprolactone (PCL) nanofibrous mats incorporating oregano essential oil (OEO) using solution blow spinning (SBS) and to evaluate their physicochemical properties, antifungal activity, and effectiveness in preserving strawberry quality during refrigerated storage. Nanofibers were produced by SBS and characterized regarding morphology, mechanical behavior, wettability, Fourier-transform infrared spectroscopy, X-ray diffraction, and thermal properties. The incorporation of OEO produced continuous, bead-free nanofibers without compromising the structural integrity of the PCL matrix. The developed mats exhibited high production efficiency, with an apparent yield of 48.5% and a production cost of US$0.0168 cm⁻², demonstrating the scalability and economic feasibility of the SBS process. In vitro assays revealed pronounced antifungal activity, achieving more than 70% inhibition of Rhizopus stolonifer growth and approximately 54% inhibition of Botrytis cinerea. When applied to strawberries stored under refrigeration, the active nanofibers significantly reduced fungal incidence and disease severity while minimizing weight loss, preserving fruit firmness, and maintaining physicochemical attributes, including soluble solids, titratable acidity, and pH, throughout storage. Consequently, treated fruits exhibited a longer postharvest shelf life than the untreated control. These findings demonstrate that SBS-produced PCL nanofibers loaded with oregano essential oil represent a scalable, cost-effective, and sustainable active packaging strategy for improving the postharvest preservation of strawberries and other highly perishable fruits.