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

Abstract

The impacts of temperature,water activity and their interactions on the growth rate and ochratoxin A (OTA)production by three Aspergilluscarbonarius isolates obtained from dried figs in Agean Region of Turkeywere investigated on Czapek yeast extract agar. The maximum specific radialgrowth rates at each set of conditions were obtained by using the primary modelof Baranyi. Correlation coefficients were varied between 96% and 99%. Optimumgrowth of all isolates was at 30°C and 0.97 aw while optimum OTAproduction was observed at 15 - 20°C and 0.97 - 0.99 aw depending onthe isolate. The assayed isolates showed varying abilities in growth rate andOTA production capacities as reported in the literature. The estimated optimumtemperature and water activity values for growth and OTA production were inaccordance with reported results for grape isolates. Temperature, wateractivity and their interactions significantly influenced the growth rate andochratoxin A production by all tested isolates (P <0.05).

Keywords

• growth rate
• ochratoxin a
• dried figs