Comparison of five essential oils on postharvest strawberry fruit quality

Strawberry fruits are very perishable and susceptible to diseases. The conventional method to control the disease is the fungicide application, which has raised health concerns. Therefore, there is a lot of interest to develop eco-friendly practices to maintain fruit quality and control fruit diseases after harvest. Plants are a natural source of metabolites that have antifungal properties. These metabolites have been used successfully in in vitro conditions to control the pathogen. These metabolites are part of the plant self-defense system. Some are volatile and can be used in storage conditions as fumigants without direct contact with fruits to control diseases. However, there are few reports on their application as a vapor phase in commercial storage conditions. The preliminary experiments have shown promising effects. Therefore, we compared five plant volatiles (thymol, cinnamon, eugenol, clove bud oil, and nonenal) to extend strawberry fruits’ shelf life (‘Jewel’, ‘Albion’, ‘Allstar’, and ‘Sweet Charlie’) and reduce fungal decay. Five plant volatiles were placed on cotton balls at a concentration of 30 ppm. Ten to 20 strawberries were placed in strawberry clamshell containers and kept at 4°C and 95% humidity for 4 weeks. Weight, titratable acidity, total soluble solid content, and fungal contamination of strawberries were recorded at the beginning of the storage and every week for four weeks. Weight loss and titratable acidity were not affected by essential oils, but such attributes were cultivar-dependent. SSC content did not change dramatically among essential oil treatments, but was highest in cinnamon oil treatment. Fungal decay was less pronounced in strawberries treated with nonenal and highest in strawberries treated with clove bud oil treatments.