Evaluation of the effect of clove essential oil as antifungal strategy in “salchichón”-type dry-cured fermented sausages

Abstract

Some of the moulds growing during the ripening of dry-cured fermented sausages produce ochratoxin A (OTA). To control its presence, the use of essential oils is gaining interest in the meat industry. The activity of different concentrations (100-1000 mu L/mL) of two clove essential oils (CEOs) obtained differently (industrially and by hydrodistillation) against Penicillium nordicum was evaluated. Samples of mycelium grown over the surface of "salchichon" portions for OTA quantification and proteomic analyses were taken after the incubation 31 days, 12 degrees C. Chemical characterisation of essential oils and visual analysis of mycelial growth were performed. Eugenol and acetyleugenol were among the major compounds in both CEOs, despite some differences. Although CEOs inhibited mould growth in a dose-dependent manner, causing mycelial development below 25 %, OTA production was stimulated as their concentrations were increased, raising levels by up to 400 % in the case of that obtained by hydrodistillation. The proteomic profile of P. nordicum revealed that the increase in OTA generation could be due to a higher abundance of proteins related to environmental stress in the presence of CEOs, activating pathways involved in the synthesis of secondary metabolites, OTA precursors, and OTA itself. The CEOs showed slight differences in their mode of action, probably due to their different chemical compositions. The use of CEO as an antiochratoxigenic agent in the meat industry is not effective despite its ability to inhibit growth, highlighting the importance of using appropriate concentrations without stimulating the OTA production and underlining the absence of a relationship between growth and OTA accumulation