Origanum dictamnus oil vapour suppresses the development of grey mould in eggplant fruit in vitro.

Andriana Stavropoulou,Nikos Tzortzakis,Naresh Magan,Kostas Loulakakis

doi:10.1155/2014/562679

Abstract

Grey mould rot (Botrytis cinerea) development in vitro or in eggplant (Solanum melongena L.) fruit was evaluated after treatment with dittany (Origanum dictamnus L.) oil (DIT) and storage at 12°C and 95% relative humidity during or following exposure to the volatiles. DIT volatiles used in different concentration (0-50-100-250 μL/L) and times of exposure (up to 120 h) examined the effects on pathogen development as well as fruit quality parameters. In vitro, fungal colony growth was inhibited with the application of DIT oil (during or after exposure) and/or time of application. Continuous exposure to oils reduced conidial germination and production with fungistatic effects observed in 250 μL/L. In vivo, fungal lesion growth and conidial production reduced in DIT-treated fruits. Interesting, in fruits preexposed to volatiles before fungal inoculation, DIT application induced fruit resistance against the pathogen, by reduced lesion growth and conidial production. Conidial viability reduced in >100 μL/L DIT oil. Fruits exposed to essential oil did not affect fruit quality related attributes in general, while skin lightness (L value) increased in 50 and 100 μL/L DIT oil. The results of the current study indicated that dittany volatiles may be considered as an alternative food preservative, eliminating disease spread in the storage/transit atmospheres.

Highlights

The economical impacts of spoiled foods and the consumer’s concerns over the safety of foods containing synthetic chemicals, as well as the rise in the consumption of fresh produce over the last decades, have driven demand for improved commercial storage/transit conditions, in order to control postharvest disease proliferation and maintain fruit quality
Organic essential oilsderived from dittany (Origanum dictamnus L.), obtained from a crop in Heraklion prefecture were extracted by hydrodistillation (Clevenger apparatus for 3 h)
This study revealed that volatile-enrichment markedly reduced spoilage by gray mould during the vegetative and reproductive phase of the fungus, which is of great importance for the disease cycle and spread

Summary

Introduction

The economical impacts of spoiled foods and the consumer’s concerns over the safety of foods containing synthetic chemicals, as well as the rise in the consumption of fresh produce over the last decades, have driven demand for improved commercial storage/transit conditions, in order to control postharvest disease proliferation and maintain fruit quality. It is a common practice the use of chemical treatments to preserve fresh produce, including chlorine- (or bromine-) based disinfectants. There has been considerable interest in extracts and essential oils (EO) from aromatic plants with antimicrobial activities for controlling pathogens and/or toxin producing microorganisms in foods which are considered as human-safe and environmentally friendly [3, 5,6,7] and can be ideal candidates for use as agrochemicals [8,9,10]

Methods

Results

Conclusion