Effect of nisin and thyme oil on storage inoculated Listeria monocytogenes and Staphylococus aureus during storage

The main objective of this study was to investigate the effect of nisin and thyme oil on Listeria monocytogenes and Staphylococcus aureus inoculated in cream. Milk skim was used in the study, a total of 12 groups including L. monocytogenes and S. aureus were inoculated and the study was divided into two work packages. In the first work package, L. monocytogenes were inoculated into each group. Subsequently, 5 mg/kg and 10 mg/kg of nisin and 0.25% and 0.50% thyme oil were added to groups other than bacterial control group. The same procedure was applied in the second work package, which is S. aureus. Microbiological follow-up of the prepared samples on the 0, 3, 5 and 7 storage days was performed. 3 replications of the experimental groups formed in both work packages were carried out and 2 parallel samples were analyzed from each sample. In the study, it was determined that using 0.50% thyme oil showed more antimicrobial effect in samples containing L. monocytogenes and S. aureus (p<0.05). Although thyme oil inhibits bacterial growth, it is observed that the sharp aroma of thyme oil suppresses the unique taste and smell of cream.