Monitoring of ochratoxin A and ochratoxin-producing fungi in traditional salami manufactured in Northern Italy

AbstractFungi have a crucial role in the correct maturation of salami, but special attention should be addressed to the production of the nephrotoxic, immunotoxic, and carcinogenic mycotoxin ochratoxin A (OTA). In a monitoring study conducted in Northern Italy, OTA was detected by liquid chromatography coupled with mass spectrometry in 13 out 133 samples of traditional salami (9.8% of the total count). Mycological analysis of these samples yielded 247 fungal isolates which were identified to species level. The most frequent species werePenicillium nalgiovense,P. solitum, andP. chrysogenum.P. nordicum, an OTA-producing species commonly found in proteinaceous food, was not found in these samples. Three isolates were found to beAspergillus westerdijkiae, an OTA-producing species. In order to check the results of the microbiological identification, 19 different strains ofAspergillus and 94 ofPenicillium were tested for the presence of a sequence common to OTA-producing fungi by real-time PCR. None of the studied isolates, including the threeA. westerdijkiae, possessed theotanpsPN target which is common to OTA-producing strains. Two out of three isolates of theA. westerdijkiae were also PCR-negative for theotanpsPN gene and did not produce OTA in culture. Conversely, this target sequence was amplified from the DNA purified from 14 salami casings including three casings harboringA. westerdijkiae. The amplification of sequences specific for OTA-producing strains performed on total g...

Source: Mycotoxin Research - January 3, 2018 Category: Toxicology Source Type: research