The combined antimicrobial effect of 0.5% CA and 0.2% OEO on L. monocytogenes, lactic acid bacteria and psychrotrophic microorganisms is shown in Fig. 1. Application of CA alone (2 × MIC in vitro) didn't lead to any significant inhibition of any group of microorganisms in comparison with control, whereas the application of OEO alone (4 × MIC in vitro) inhibited the growth of psychrotrophic microorganisms (P < 0.001). The combined application of CA and OEO resulted in significantly lower populations of L. monocytogenes in comparison with control or individual applications of the antimicrobials (P < 0.001) as the numbers of L. monocytogenes decreased during storage from 4.63 log CFU/g to 3.68 log CFU/g. When citric acid was added, even more pronounced decrease from 4.70 log CFU/g to 2.38 log CFU/g was noted. The combination of CA and OEO was less effective on population of lactic acid bacteria, when only the mixture with citric acid led to significant inhibition in comparison with the control group (P < 0.001). The psychrotrophic microorganisms were inhibited by mixture of CA and OEO with or without citric acid to a larger extend, as the numbers were more than 2 log CFU/g lower in the end of the storage then the numbers in the control group.