The composition of 18 essential oils was determined using gas chromatography–mass spectrometry, and their antilisterial activity was evaluated by the disk diffusion method, followed by the determination of the minimum inhibitory and minimum bactericidal concentrations. The most active essential oils were oregano, thyme, cinnamon, winter savory, and clove, with MIC values ranging from 0.09 to 1.78 µL/mL. We investigated the biofilm-forming potential of Listeria monocytogenes on polystyrene at 5 °C, 15 °C, and 37 °C in three different media. The formation of biofilm was found to be dependent on the temperature and the availability of nutrients. After treatment with selected essential oils, the reduction in biofilm biomass was in the range of 32.61% and 78.62%. Micromorphological changes in the L. monocytogenes treated by oregano and thyme essential oils were observed in the form of impaired cell integrity and cell lyses by using scanning electron microscope. Oregano and thyme essential oils (MIC and 2MIC) significantly (p < 0.05) reduced the population of L. monocytogenes in minced pork meat during storage at 4 °C. In conclusion, the obtained results indicated the good activity of some selected essential oils on L. monocytogenes, with bacteriostatic, bactericidal, and antibiofilm effects at very low concentrations.

Yersiniosis, one of the leading foodborne infections in the European Union, is caused by Yersinia enterocolitica. In this study, the antibacterial and antibiofilm effects of cinnamon (Cinnamomum zeylanicum Nees), clove (Syzygium aromaticum L.), oregano (Origanum vulgare L.), rosemary (Rosmarinus officinalis L.), thyme (Thymus vulgaris L.), and winter savory (Satureja montana L.) essential oils were investigated against Y. enterocolitica strains belonging to the bioserotype 4/O:3. Cinnamon essential oil showed the highest antibacterial activity, with an MIC value 0.09 µL/mL, followed by oregano and thyme essential oils, with MIC values from 0.09 to 0.18 µL/mL, and from 0.18 to 0.23 µL/mL, respectively. Thyme essential oil at 0.23 µL/g (MIC) and at 0.46 µL/g (2MIC) significantly (p < 0.05) reduced the number of Y. enterocolitica by 0.38 log CFU/g and 0.64 log CFU/g, respectively, in minced pork meat during storage at 4 °C for 4 days. The Y. enterocolitica strains formed biofilms at 15 °C and 37 °C in tryptic soy broth and Luria–Bertani broth, while no biofilms were obtained at 5 °C, and in meat broth nutrient media. Applying the minimum bactericidal concentrations of cinnamon, clove, oregano, rosemary, thyme, and winter savory essential oils on preformed biofilms led to significant reductions being observed in the range from 45.34% to 78.89%. A scanning electron microscopy assay showed the devastating impact of oregano and thyme essential oils on the morphology of Y. enterocolitica bacterial cells. In conclusion, the results of this study show that essential oils possess high anti-Yersinia and antibiofilm effects.

The goal of this study was to determine the concentrations of 16 PAHs (PAH16) naphthalene—Nap, acenaphthylene—Anl, acenaphthene—Ane, fluorene—Flu, phenanthrene—Phen, anthracene—Ant, fluoranthene—Flt, pyrene—Pyr, benz[a]anthracene—BaA, chrysene—Chry, benzo[b]fluoranthene—BbF, benzo[k]fluoranthene—BkF, benzo[a]pyrene—BaP, indeno[1,2,3-cd]pyrene—InP, dibenz[a,h]anthracene—DahA and benzo[g,h,i]perylene—BghiP) in Slavonska slanina traditionally smoked bacon over open fire and industrially smoked on a smoke generator with a heated plate. In the samples of Slavoska slanina smoked in a traditional manner, the presence of 11 out of 16 analyzed PAHs was determined (Nap, Anl, Ane, Fln, Ant, Phen, Flt, BaA, Pyr, BbF, BkF). In the samples smoked in industrial conditions, only 2 out of 16 (Nap, Anl) were quantified. In the samples smoked with open fire (the traditional method), PAH4 (BaA, BaP BbF, Chry) concentations were as follows: 14.84 μg kg⁻¹ in the middle, 10.60 μg kg⁻¹ on the surface and 17.37 μg kg⁻¹ in the skin, while the PAH4 content in the samples smoked in industrial conditions were below the level of quantification (<LOQ). The content of carcinogenic BaP was below the limit of quantification in all investigated samples. These findings support the fact that traditional smoking may result in a product safe for consumption, as far as the prescribed legislative recommendations are concerned, but constant monitoring is still needed.

Salmonella Enteritidis is a serious foodborne threat, being the most reported Salmonella serovar in the past several years. Biofilm formation contributes significantly to its persistence and resistance in food processing environments, making it harder to eliminate using conventional disinfectants. Recently, essential oils have emerged as promising natural alternatives due to their antimicrobial and anti-biofilm properties. In this study, the biofilm-forming ability of Salmonella Enteritidis, isolated from chicken meat, was evaluated under various nutrient conditions and temperatures. Furthermore, the anti-biofilm activity of essential oils derived from oregano, cinnamon, rosemary, clove, and thyme was assessed against strong and moderate biofilms formed by Salmonella Enteritidis. The isolates demonstrated the capacity to form biofilms in tryptic soy broth, meat broth, and Luria–Bertani broth at 37 °C, 15 °C, and 5 °C. All selected essential oils, at their minimum bactericidal concentrations, effectively reduced preformed biofilms by between 36.98% to 74.83%. The destructive effect of essential oils on Salmonella Enteritidis bacterial cells was further confirmed through scanning electron microscopy analysis. In conclusion, the selected essential oils exhibited promising anti-biofilm potential and may serve as effective natural agents for controlling biofilm-associated contamination by Salmonella Enteritidis.

This study examined the safety of meat products from north Serbia (Vojvodina), smoked in traditional conditions, from a PAH point of view, and assessed the possibility of their reduction in these types of products. Samples of dry cured meat products, bacons and dry fermented sausages smoked in six different chambers on the territory of Vojvodina were examined. The contents of 16 polycyclic aromatic hydrocarbons, from the United States Environmental Protection Agency list (16 US-EPA PAHs), and sensory quality of meat products were determined. The total content of 16 US-EPA PAHs in dry cured meat products was in the range from 99.73 μg/kg to 412.76 μg/kg; in bacons it was in the range from 36.43 μg/kg to 188.86 μg/kg; and in dry fermented sausages in the range from 47.23 μg/kg to 270.60 μg/kg. The lowest contents of 16 US-EPA PAHs compounds were determined in meat products smoked in traditional conditions during 3–5 days (3–4 h per day) at a distance of 2.5 m between the fire and products. Generally, it can be concluded that shortening of smoking process is justified, because products of good sensory quality and with decreased content of PAHs compounds were obtained. Benzo[a]pyrene, whose maximum allowed content in smoked meat products is 2 μg/kg, was below the limit of detection in all examined traditional meat products from Vojvodina. Also, contents of PAH4, sum of benz[a]anthracene, chrysene, benzo[a]pyrene and benzo[b]fluoranthene, were in the range from ND to 2.22 μg/kg, still greatly lower than the set maximum value. These results indicated the safety of dry cured meat products, bacons and dry fermented sausages from the territory of north Serbia (Vojvodina), as defined by EU Regulation 2023/915 criteria for PAHs contents.