Evaluation of the efficacy of autochthonous biocontrol agents for controlling ochratoxin A production in simulated ripening of dry-cured ham

Dry-cured hams are colonised by ochratoxin A (OTA)-producing fungi Penicillium nordicum and Aspergillus westerdijkiae during their ripening. The aim of this study was to evaluate the efficacy of a mixed culture of biocontrol agents (BCAs) with Debaryomyces hansenii, Staphylococcus xylosus and Penicillium chrysogenum on the growth and OTA production by three ochratoxigenic mould's strains during processing simulation of dry-cured ham. Both toxigenic moulds and BCAs were inoculated by dipping the ham pieces and were incubated for 90 days following the environmental conditions of traditional ripening. The effect of the BCAs on ochratoxigenic moulds was observed macroscopically, and the growth of the microorganisms was determined by plate count. OTA from mycelium and ham samples was quantified by using a Orbitrap Q-Exactive Plus mass spectrometer at 15, 30, 45, 60, and 90 days of incubation, at which time the water activity was assessed. Phenotypic differences in the mycelium colour were obtained in the presence of BCAs, which significantly decreased the OTA concentration in both mycelium and ham inoculated with the ochratoxigenic strains during 90 days of the ripening. In conclusion, D. hansenii, S. xylosus, and P. chrysogenum could be an efficient mixed protective culture to reduce the hazard of OTA in dry-cured ham.