Determining effect of ethyl formate and Vapormate® on disinfestation efficiency and organoleptic quality of date fruits

Perfectly integrated into the Tunisian economy, date sector is undergoing a great expansion in production and exports. Infestation is a major problem encountered during the dates’ postharvest period. Consequently, there is a need to maintain fruit quality during handling, packaging and storage. Currently, after the methyl bromide (MB) restriction, the industry needs an efficient and environmental-friendly alternative against insects. In this study, ethyl formate (EF) had been chosen to fumigate dates of Deglet Nour variety. Initially, trials at laboratory scale were performed with the most resistant larvae stage of the carob moth (Ectomyelois ceratoniae). For this purpose, three EF concentrations (114.4, 127.8, and 143 g/m3) and two exposure durations (2 and 3 h) were tested. Results revealed that the most efficient combination was 143 g/m3 of EF for 2 h, which caused 98.12% mortality. Then, experiments were undertaken at a semi-industry scale with Vapormate®, the commercial version of EF containing a combination of EF and CO2. The mortality rate was further improved, reaching 100%. However, the CO2 synergistic effect was not demonstrated. In addition, the effects of EF and Vapormate® on the quality of fumigated fruits regarding color, sugar content and aromatic composition was assessed and discussed. No changes in fruit quality were observed after fumigation.