Antifungal effect of the tea tree essential oil (Melaleuca alternifolia) against Penicillium griseofulvum and Penicillium verrucosum

Abstract

ObjectivesLentil and dry grapes are foods with high nutritional value, commonly consumed in Morocco. Their microbiological quality is widely studied; however, their mycological quality was less investigated. On the other hand, the antifungal potential of essential oils against Penicillium spp. and its mycotoxins was demonstrated. The aim of this work is to investigate the antifungal activities of Melaleuca alternifolia essential oil (M. alternifolia EO) against Penicillium griseofulvum (P. griseofulvum) isolated from lentil (Lens culinaris) and Penicillium verrucosum (P. verrucosum) isolated from dry grapes (Vitis vinifera L.) in Northern Morocco. MethodsEight samples of lentil and nine samples of dry grapes have been analyzed. Eight strains belonging to five species of Penicillium have been isolated and identified. The identification was based on the microscopic, physiological, and cultural characteristics of growth under standard conditions. Mycotoxins production was highlighted by Thin Layer Chromatography (TLC). ResultsP. griseofulvum produced Terrestric acid and Ochratoxin A in the Yeast Extract Sucrose agar (YES) medium, while P. verrucosum produced only Terrestric acid. The major component of M. alternifolia EO was terpinene-4-ol (23.06%). This component was identified by Gas Chromatography coupled with Mass Spectrometry (GC–MS). Our results showed that the addition of M. alternifolia EO, at different concentrations to the culture medium, was completely stopped the production of Terrestric acid and Ochratoxin A by P. griseofulvum. Mycelial growth was also inhibited. The same effect was demonstrated on the growth and mycotoxins production on P. verrucosum. ConclusionsMelaleuca alternifolia EO is suitable for control of post-harvest Penicillium contaminating lentil and dry grapes.