Growth Inhibition of Aspergillus flavus Isolated from Pistachio by Secondary Metabolites

Pistachio nut is a strategic product throughout the world, especially in Iran. There are some problems that reduce production and export of pistachios, for example, postharvest fungi, especially Aspergillus spp., that lead to production of mycotoxins. Nowadays the use of chemical and synthetic antifungals is discouraged and reduced because of health risks to mankind and nature. In present study we investigated the antifungal activities of carvacrol and allyl isothiocyanate (AITC) on conidia germination and mycelial growth in Aspergillus flavus at six concentrations and two observation times (3 and 7 days after inoculum). The results indicated that these compounds could inhibit spore germination and mycelial growth completely at 12 and 2.9 μL L-1 for mycelial growth and conidia germination, respectively. In addition, the ED50 and ED95 values were determined for all treatments. It was concluded that the natural compounds examined in the present study could be used as antifungal agents against food spoilage and mycotoxin producing fungi. Further studies on natural antifungal compounds to replace chemical fungicides are required.