The effect of Zataria multiflora Boiss Essential oil on the growth and citrinin production of Penicillium citrinum in culture media and cheese

The effect of Zataria multiflora Boiss Essential oil (EO) on the growth, spore production, and citrinin production of Penicellium citrinum PTCC 5304 in the culture media as well as Iranian ultra-filtered white cheese in brine was investigated. Radial growth and spore production on the potato dextrose agar (PDA) were effectively inhibited by EO in a dose-dependent manner. At 200 ppm, the radial growth and sporulation declined by 92% and 100%, respectively. The growth was completely prevented at 400 ppm of EO on PDA and the minimum fungicidal concentration (MFC) of the oil was estimated at 400 ppm. Furthermore, the Zataria multiflora also significantly suppressed the mycelial growth and citrinin production in broth medium at all investigated concentrations (P < 0.05). At 150 ppm of EO, the citrinin accumulation and mycelial growth reduced by 88.6% and 89.6%, respectively. The EO was tested at all concentrations and the findings show an inhibitory effect of P. citrinum against the radial fungal growth and citrinin production in cheese. However, no concentration of EO could completely inhibit the growth and production of citrinin in cheese. We therefore concluded that Zataria multiflora has the potential to substitute the antifungal chemicals as a natural inhibitor to control the growth of molds in foods such as cheese.