Growth and Ochratoxin A Production by Aspergillus carbonarius Isolated From Dried Figs In Aegean Region of Turkey Affected by Temperature and Water Activity

The impacts of temperature, water activity and their interactions on the growth rate and ochratoxin A (OTA) production by three Aspergillus carbonarius isolates obtained from dried figs in Aegean region of Turkey were investigated on Czapek yeast extract agar. The maximum specific radial growth rates at each set of conditions were obtained by using the primary model of Baranyi. Correlation coefficients were varied between 96% and 99%. Optimum growth of all isolates was at 30 °C and 0.97 aw while optimum OTA production was observed at 15 – 20 °C and 0.97-0.99 aw depending on the isolate. The assayed isolates showed varying abilities in growth rate and OTA production capacities as reported in the literature. The estimated optimum temperature and water activity values for growth and OTA production were in accordance with reported results for grape isolates. Temperature, water activity and their interactions significantly influenced the growth rate and ochratoxin A production by all tested isolates (P <0.05).