Effect of Penicillium nordicum contamination rates on ochratoxin A accumulation in dry-cured salami

- Evaluation of P. nordicum contribution to OTA accumulation in dry-cured salami.
- P. nordicum colonizes salami and produces OTA if co-inoculated at low concentrations.
- P. nalgiovense couldn't guarantee a protective effect from P. nordicum colonization.
- LAMP assay is able to detect P. nordicum on salami surface during seasoning process.

Fungal starter, such as Penicillium nalgiovense, are commonly used to inoculate sausages before seasoning process. However, Penicillium nordicum, a well-known ochratoxin A (OTA) producer frequently isolated from seasoning rooms, could colonize the casing surface during the early stage of production. The relationship between OTA accumulation and simultaneous inoculation of P. nalgiovense and P. nordicum at different rates was evaluated. After 14 days of seasoning, the persistence of P. nordicum was assessed by LAMP assay revealing its capability to colonize and grow on salami surface at all the contamination rates. At the end of seasoning, OTA was accumulated both in mycelium and dry-cured meat when P. nordicum contamination rate ranged from 25% to 100% of inoculum, while no OTA was detected in dry-cured meat at 2.5% and 0.25%. Results demonstrated that contamination of fungal starter by P. nordicum could represent a serious concern during salami production and therefore represents an important critical point to be monitored.