Proteomic approach to unveil the ochratoxin A repression by Debaryomyces hansenii and rosemary on Penicillium nordicum during dry-cured fermented sausages ripening

Penicillium nordicum is the main ochratoxin A (OTA) producer in dry-cured meat products. The aim of the study was to test Debaryomyces hansenii and rosemary derivatives as biocontrol agents (BCAs) against P. nordicum during the industrial manufacturing of dry-cured fermented sausages. Eighteen batches of sausages with different combinations of the BCAs were made. D. hansenii FHSCC253H was inoculated in the meat dough or on the casings. Rosemary was used either as an ingredient, for macerating the casings or by applying its essential oil. P. nordicum was finally added on the surface of the sausages by immersion in a solution containing 106 spores/mL. OTA was quantified by uHPLC-MS/MS QqQ after ripening time and comparative proteomic analyses were carried out to elucidate the involved modes of action. OTA accumulation decreased when the yeast or rosemary leaves were added in the meat dough as well as when the casings were macerated with the herb. The yeast presence provoked the reduction in the abundance of P. nordicum proteins involved in OTA biosynthesis, and its combination with rosemary interfered with the cell wall integrity pathway linked to mycotoxin synthesis in moulds. The addition of rosemary leaves and the casing maceration changed the abundance of proteins involved in ergosterol biosynthesis. Furthermore, the maceration affected to proteins involved in the synthesis of phenylalanine, essential for OTA synthesis. In conclusion, the yeast D. hansenii and the rosemary leaves, alone or in combination, could be proposed as BCAs to hamper the P. nordicum OTA production during the industrial elaboration of dry-cured fermented sausages.