Biobased Postharvest Treatment Using Eucalyptus Essential Oils in Edible Coatings to Inhibit Colletotrichum acutatum and Prolong Strawberry Shelf Life

Strawberries are economically valuable but highly perishable fruits, mainly due to fungal spoilage, with no fungicides currently registered for postharvest use. This study aimed to develop a biobased postharvest treatment for strawberries focusing on fungal control and shelf-life extension. The antifungal activity of <i>Eucalyptus staigeriana</i>, <i>Eucalyptus urograndis</i>, and their binary mixture was evaluated in vitro against the spoilage fungus <i>Colletotrichum acutatum</i>. The effects on pathogen morphology, in vivo efficacy when incorporated into carboxymethylcellulose (CMC), and impacts on postharvest and sensory quality of strawberries were also assessed. <i>E. staigeriana</i> EO showed the highest antifungal activity in vitro. In vivo, the incorporation of <i>E. staigeriana</i> EO into CMC significantly reduced disease severity when applied curatively. Treated fruits exhibited less fungal decay during refrigerated storage, indicating improved preservation. However, sensory evaluation revealed changes mainly in the aroma of the fruit. These results suggest that <i>E. staigeriana</i> EO combined with CMC coating is a promising postharvest antifungal treatment for strawberries, though further research is needed to optimize the formulation and reduce sensory impacts.