Influence of abiotic parameters on ochratoxin A production by a Penicillium nordicum strain in dry-cured meat model systems

OTA production from an ochratoxigenic Penicillium nordicum strain was studied in artificial inoculation trials managed both in a dry-cured pork-based medium (DCM) and in dry-cured pork cores. The experimental region defined by 7-23 degrees C temperature, 0.83-0.97 a(w), and 7-21 days of incubation was considered for DCM in the applied Central Composite Design (CCD). A(w) > 0.92, temperature > 18 degrees C and incubation time protracted to 21 days strongly enhanced OTA production. The conditions of CCD central point (a(w) = 0.90. temperature = 15 degrees C and days of incubation = 14) and those predicted as the most suitable for OTA production in DCM, were tested in dry-cured pork samples incubated up to 190 days. A ten-fold increase in OTA (0.04-0.41 mu g/g) was achieved when the temperature rose from 15 degrees C up to 20 degrees C, an over twenty-fold (0.02-0.43 mu g/g) when switching from 0.90 to 0.93 a(w). The results can be useful as guidelines for critical control points (CCPs) detection in dry-curing processing to prevent OTA contamination of the products. (C) 2010 Elsevier Ltd. All rights reserved.