Antifungal activity in vitro and on food of the essential oil extracted from pompia (Citrus limon var. pompia) leaves against Penicillium digitatum applied by vapor contact

BACKGROUND: In recent years, the interest in the use of natural compounds as possible substitutes of chemicals, to prevent microbial spoilage on food has grown. The antimicrobial activity of the essential oils (EOs) is well known and nowadays there is a renewed interest in their application as natural preservatives in postharvest management. The aims of this study were the characterization of the EO extracted from pompia leaves and the evaluation of its effectiveness for the control of the postharvest decay agent Penicillium digitatum, when applied as vapour contact in new airtight boxes, supplied with a heating system. RESULTS: The fumigations were performed in vitro and on food by using two concentrations of the EO, heated at controlled temperature. The headspace analysis revealed that the heating of the EO favoured the evaporation of the volatile compounds, without altering their functionality. The treatments reduced the pathogen growth in vitro and rots on inoculated food by about 50 %. CONCLUSION: The chemical analysis of the vapour composition demonstrated that the heating of the oil did not alter the components and thus the antimicrobial effect of the oil. The treatment by vapor contact with the EO resulted effective in controlling the pathogen growth in vitro, but above all, it was successful in halving rots in vivo. Due to their bioactivity in vapour phase EOs could be delivered as fumigant during postharvest protection, however, the techniques commonly employed are not ideals to simulate real pre-treatment conditions. The new device allows reproducing real large-scale conditions. This article is protected by copyright. All rights reserved.