Inhibitory Effects of Essential Oils of Cinnamon zeylanicum and Myristica fragrans against Brucella abortus 544 Inoculated in Fresh Baladi Cheese

Abstract

Background: Essential Oils (EOs) are natural metabolic products of plants that contain a condensed chemical hydrophobic liquid compounds. The aim of this study was to evaluate inhibitory effects of EOs of Cinnamon zeylanicum and Myristica fragrans against Brucella abortus 544 inoculated in fresh Baladi cheese.

Methods: Fresh Baladi cheese was manufactured from experimentally contaminated milk with B. abortus 544 in combination of EOs of C. zeylanicum or M. fragrans. Cheese samples were periodically subjected to further microbiological surveys at different storage times (0, 1, 24, 48, 72, and 96 h). The inhibition zone diameter and Minimum Inhibitory Concentration (MIC) against tested strain were also determined. Statistical analyses were conducted by GraphPad Prism Statistical Software.

Results: The inhibition zone diameter of the paper disk were 9.5±0.5 and 16±0.57 mm at 1% concentration of M. fragrans and C. zeylanicum EOs, respectively; and 15±0.28 and 21±0.76 mm at 5% concentration of M. fragrans and C. zeylanicum EOs, respectively. The values of inhibition zone diameters were significantly (p<0.0001) different between the two selected concentrations of 1% and 5% for the studied EOs. Also, anti-Brucella activity of C. zeylanicum was significantly (p<0.0001) more than that of M. fragrans EO.

Conclusion: Due to the appropriate anti-Brucella activity, C. zeylanicum EO could be applied as an effective natural preservative in the production of fresh Baladi cheese. Conversely, using M. fragrans EO could not protect the fresh Baladi cheese against Brucella.