Modeling dependence of growth inhibition of Salmonella Typhimurium and Listeria monocytogenes by oregano or thyme essential oils on the chemical composition of minced pork

The aim of this study was to compare the antimicrobial effect of selected essential oils (EOs) at concentration of 1% in minced pork from five different meat cuts (loin, ham, shoulder, neck, and belly) and to assess the influence of the chemical parameters of meat on EO efficiency, determined by the decrease of pathogens in comparison to a control in samples after storage at 3 degrees C/7 d in a vacuum. The inhibition was significant (p < .05) only in minced pork from meat cuts with a fat content lower than 5% (leg, loin and shoulder). Salmonella enterica serovar Typhimurium was more sensitive than Listeria monocytogenes and oregano was more effective than thyme (p < .001). The inhibition of S. Typhimurium depended mainly on the fat content (logarithmic dependence) and to a lesser degree on the pH, whereas pH was not found to be a significant predictor in the case of L. monocytogenes. The results of this study show that only lean minced meat (with a fat content max. 5%) is a suitable matrix for pathogen control by EOs.