Efecto de agentes para el biocontrol de mohos ocratoxigénicos en embutidos curado-madurados

Resum

To control ochratoxin A (OTA)-producing moulds in dry-cured fermented sausages, different natural strategies based on biocontrol agents (BCAs) have been developed. The main objective of this Doctoral Thesis was to design a method against ochratoxigenic moulds (Penicillium nordicum and Aspergillus westerdijkiae) in dry-cured fermented sausages using Enterococcus faecium, Debaryomyces hansenii and Penicillium chrysogenum. Oregano, thyme, rosemary (including rosemary essential oil (REO)) and an acorn extract were also tested. After OTA analysis, their modes of action and their effects on the native population and quality parameters of dry-cured fermented sausages were investigated. Thyme and REO did not show the desirable effect on the OTA production. Different modes of action were revealed depending on the BCAs. P. chrysogenum seems to compete by nutrients and space. D. hansenii decreased proteins involved in OTA biosynthesis and the cell wall integrity pathway (CWI), while the cell wall seems to be the oregano’s target sites. Rosemary leaves reduced ergosterol content, while the casings macerated with them affected the CWI, ergosterol biosynthesis and OTA biosynthesis in P. nordicum. The addition of rosemary leaves as ingredient or by macerating the casings of dry-cured fermented sausages, together with D. hansenii, is a promising biocontrol strategy since their combination enhanced the reduction of proteins related to CWI and OTA biosynthesis without negatively altering the quality parameters.