CHITOSAN COATINGS ENRICHED WITH CITRUS ESSENTIAL OILS FOR PREVENTING POSTHARVEST SPOILAGE BY ASPERGILLUS FLAVUS IN CHERRY TOMATOES

In recent years, considerable attention has been directed toward natural essential oils (EOs), as a promising approach for controlling postharvest decay in perishable fruits and reducing chemical-based treatments. However, the use of these compounds is often limited due to their intense aroma and their potential toxicity. The incorporation of EOs into edible coating formulations has been investigated as an effective approach to solve some of these problems, by lowering the diffusion processes and maintaining high concentrations of active molecules on the surface of the fruit. Biodegradable coatings based on chitosan incorporating either bergamot or bitter orange EOs at different concentrations were evaluated against Aspergillus flavus, under in vitro conditions, in terms of mycelium growth and spore germination inhibition, and under in vivo condition on inoculated cherry tomatoes, stored at 20°C. A mixture based on chitosan-2% bergamot essential oil proved to be the most affective coating to reduce mycelial growth (80% reduction) and spore germination (90% reduction) compared with the control (p < 0.05). With respect to the in vivo assay, chitosan coatings containing either bergamot or bitter orange essential oil at a concentration of 2% were able to reduce postharvest decay in inoculated cherry tomatoes by 55 and 40%, respectively.