New insight on safety and quality of salami production related to Penicillium species

Fermented meat products are unique and often represented as an element of culinary heritage and gastronomic identity. Together with meat enzymes and bacteria, molds are very important in the ripening of some dry fermented meat products. Fungal starter cultures, contribute to the development of the typical sausage's flavor through their lipolytic and proteolytic activities. They also played an important role in preventing lipid oxidations and counteracting undesirable microorganisms. Various genera of fungi could colonize salami but Penicillium species are predominant, and above all P. nalgiovense, P. olsonii, P. brevicompactum, P. chrysogenum and a new recently described species P. salamii. Recently we investigated the technological aspects of a P. salamii strain, already well adapted to the ripening conditions. Its interesting attitude to the seasoning process of meat resulted in fast growth, with high lipolytic and proteolytic activities suggesting it as promising candidate to be used in new fungal starter formulations for meat industry. On the other hand, depending on its peculiar composition, the surface mycobiota could be colonized by undesirable molds, like P. nordicum an important and consistent producer of the potent nephrotoxin ochratoxin A (OTA), widely reported as contaminant of dry-cured meat products. In relation to monitoring and addressing the safety of seasoning of salami we developed a sensitive and easy to use LAMP assay for P. nordicum detection on salami surface co-inoculated with P. nalgiovense and P. nordicum at different rates. In addition, we monitored the expression of a keygene of OTA biosynthesis in P. nordicum and toxin accumulation in meat during the seasoning process, observing that expression profile was consistent with OTA accumulation. Results revealed that P. nordicum monitoring, since early steps of seasoning, could represent a valid and fast molecular tool for early alert of the possible OTA accumulation