Tabriz University of Medical Sciences Pharmaceutical Sciences 1735-403X 22 4 2016 12 30 Effects of Ziziphora clinopodioides Essential Oil and Nisin on the Microbiological Properties of Milk 272 278 10.15171/PS.2016.42 EN Yasser Shahbazi Journal Article 10.15171/PS.2016.42 2016 04 14 2016 07 31 Background: Recently, because of increasing concern regarding food safety containing chemical additives, remarkable attempts have been made and progress to develop natural antibacterial compounds such as essential oils. Methods: This study was conducted to determine antibacterial activities of Ziziphora clinopodioides essential oil (ZEO) alone and in combination with different concentrations of nisin to increase shelf life and control Salmonella typhimurium and Staphylococcus aureus in milk stored at refrigerated temperature. Results: The dominant constituents of ZEO in our study were carvacrol (65.22%) and thymol (19.51%). The microbial population was decreased significantly with addition of ZEO and nisin, increased their concentrations and longer storage time. It was found that milk samples containing ZEO at 0.2% and nisin at 500 IU mL-1 had significantly lower microbial population (p<0.05). Conclusions: Based on our findings, ZEO and nisin extended the shelf life of milk and may be used as natural antibacterial compounds in food products such as milk and dairy products.