Volatile organic compounds produced by some synthetic essential oils as biological fumigants against Botrytis cinerea on apples

Background: Gray mold, attributed to Botrytis cinerea, poses a substantial threat to food security in fruit-growing regions impacted by global climate change. Addressing this disease requires the utilization of either resilient plant varieties or advanced technological interventions. In this study, the research focused on examining the volatile organic compounds (VOCs) emitted by synthetic essential oils, namely thymol, eugenol, 1,8-cineol, and their combination, as potential biological fumigants against B . cinerea on Golden Delicious apples. Results: In this study, a total of 53 compounds were identified and categorized into six distinct classes, which included (1) terpenes, (2) esters, (3) C6 compounds, (4) alcohols, (5) acids, and (6) aldehydes. The results we obtained revealed significant variations in the volatile compounds present in apples after harvest when treated with different essential oils to combat B. cinerea. Among the VOCs found in the fruits, the most abundant ones were pentanal, nerol, and ethyl octanoate. The essential oil combination of thymol, eugenol, and 1,8-cineol (Thy + Eug + Fun) had the most significant impact on the volatile compound content in the fruits. Conversely, both B. cinerea and the essential oils were observed to increase the volatile organic compound content in the fruits after harvest. Conclusion: The findings from this study underscore the significance of essential oils as effective biological fumigants for countering Botrytis cinerea on apples. Furthermore, the study suggests that these essential oils have the potential to influence the composition of volatile organic compounds in postharvest apples. This research offers valuable insights into the intricate interplay between volatile organic compounds and essential oils in apples, emphasizing the critical role of essential oils in preserving fruit quality during the post-harvest period. Graphical abstract: [Figure not available: see fulltext.]. © 2023, The Author(s).