Purpose: This study was done to screen gaseous EOs with inhibitory activities against foodborne pathogens (Salmonella enterica and Listeria monocytogenes) and spoilage microorganisms (Erwinia spp. and Pseudomonas aeruginosa) and to determine the minimal inhibitory concentrations (MICs) and minimal lethal concentrations (MLCs) of gaseous EOs against those microorganisms.
Methods: In total, 100 types of commercial EOs were obtained. Experimental apparatus to screen and measure the antimicrobial activities of gaseous EOs were constructed using airtight container and medium with pH indicator. Using the apparatus, EOs with inhibitory activities against S. enterica, L. monocytogenes, Erwinia spp., and P. aeruginosa were screened, and their MIC and MLC values were measured.
Results: Thirty-five types of gaseous EOs showed inhibitory activities against S. enterica, and gaseous cinnamon leaf oil showed the lowest MIC (0.0391 µl/ml) and MLC (0.0391 µl/ml). Against L. monocytogenes, 43 types of gaseous EOs showed antimicrobial activities, and gaseous cinnamon bark, cinnamon leaf, clove bud, oregano, oregano spanish, and thyme thymol oils showed the lowest MIC (0.0781 µl/ml) and MLC (0.0781 µl/ml). For Erwinia spp. and P. aeruginosa, 17 and 13 types of gaseous EOs, respectively, showed antimicrobial activities. Gaseous thyme thymol, oregano, and cinnamon leaf oils showed the lowest MIC (0.625 µl/ml) and MLC (0.625 µl/ml) against Erwinia spp. Against P. aeruginosa, gaseous garlic oil had the highest antimicrobial activity and its MIC and MLC values were 0.625 µl/ml.
Significance: Gaseous EOs showing antimicrobial activities against S. enterica, L. monocytogenes, Erwinia spp., and P. aeruginosa were screened, and their MIC and MLC values were determined.