Study of Anti-Listeria Effects of Stachys Lavandulifolia Vachl Essential Oil in Ardabil Traditional Cheese

Nowadays, plant essential oils are of interest to food industry researchers and are used as natural and safe preservatives in food materials because of their antibacterial and antioxidant properties. The aim of this study was to evaluation of antibacterial activity of Stachys lavandulifolia essential oil against listeria monocytogenes growth in Ardabil traditional cheese.

In this experimental study, aerial parts of Stachys lavandulifolia preparation as dried plant and its essential oil was isolation and identification. Essential oil in 0.03- 0.06 and 0.12 concentration with 103cfu/ml Listeria monocytogenes was inoculated in the milk samples that were prepared for the production of cheese. The cheese samples were stored for 60 day at 7 °C and during 1, 7, 15, 30, 45 and 60 days were counted in surface culture to examine the quality growth of Listeria and total aerobic bacteria. The data were analyzed with Repeated measurement ANOVA with SPSS 22 and P-values less than 0.05 were considered significant.

Use of essential oil concentrations have significant effect on reducing total bacteria and Listeria growth in compared to the control groups (p<0.001). Moreover, it was observed that bacterial growth declined logarithmically with increases in the concentration of the essential oil (p<0.001). Use of 0.12 concentration of essential oil has the greatest antimicrobial effect.

Essential oil of Stachys lavandulifolia has antibacterial effect on Listeria monocytogenes and total aerobic bacteria, so that use of 0.06 of essential oil can improve the microbiological and safety properties of Ardabil traditional cheese and, also, can make desirable organoleptic characteristics.