Effects of selected natural preservatives on the mycelial growth and ochratoxin A production of the food-related moulds and .

The present study examines the influence of the natural preservatives carvacrol, eugenol, -cinnamaldehyde and the essential oil (EO) on ochratoxin A (OTA) production and the mycelial growth of two food-related moulds, and , by broth macro-dilution assay for 21 days. With the addition of ½ minimum inhibitory concentration (MIC) carvacrol, eugenol and EO, the mycelial dry weight of both moulds decreased significantly over the whole incubation period of 7, 14 and 21 days. -cinnamaldehyde slightly stimulated the growth of and at 14 and 21 days of incubation. Growth inhibition did not accompany inhibition of OTA production. Although the growth of both moulds was inhibited after the addition of ½ MIC carvacrol, eugenol and EO, the OTA production of the strong mycotoxin producer was stimulated. Only -cinnamaldehyde inhibited the production of OTA with the addition of ½ MIC. produced significantly less OTA than , and its mycotoxin production was almost completely inhibited by the addition of ½ MIC of the natural preservatives.