Salting of dry-cured meat – A potential cause of contamination with the ochratoxin A-producing species Penicillium nordicum

Abstract

Penicillium nordicum is a known contaminant of protein-rich foods and is primarily found on dry-cured meat products. It is an important producer of the mycotoxin ochratoxin A, which has nephrotoxic and cancerogenic activities. Recently a high number of P. nordicum strains was isolated from different dry-cured meat products from one of the Slovenian meat-processing plants. Since we have isolated P. nordicum in high counts also from Artic habitats, such as sea water and sea ice and due to its ability to grow well at low temperatures and at increased salinity, sea salt was suspected as the possible source of P. nordicum. In the present study contamination of meat products, air in the meat-processing plant and sea salt used for salting were analysed. When 50 g of salt sample from a sealed package was dissolved in sterile water and filtered, 12 colonies of P. nordicum were obtained on solid medium incubated at 15 °C, while a salt sample from an open vessel in the meat-processing area developed high, uncountable number of colonies. Amplified fragment length polymorphism analyses of P. nordicum isolates from different sources showed that contamination of meat products via salt was possible. Three selected isolates examined for extrolites all produced ochratoxin A. As contamination of dry-cured meat products with P. nordicum represents a potential health risk for consumers and workers in the meat-processing plants, salt should be taken into account as a potential cause of such contaminations.