In-vitro Assessment of Antimicrobial, Antibiofilm and Antioxidant Potential of Essential Oil from Rosemary (Rosmarinus officinalis L.)

The present study was conducted to investigate in-vitro antimicrobial, antibiofilm and antioxidant efficacy of Rosemary essential oil (REO) for its potential application in meat products. The oil was tested against four Gram positive (Bacilluscereus, Listeria monocytogenes, Staphylococcus aureus and Enterococcus faecalis) and six Gram negative (Salmonella entericaserovar Typhi, Escherichia coli, Shigella flexneri, Pseudomonas aeruginosa, Proteus mirabilis and Klebsiella pneumoniae) organisms using zone of inhibition and Minimum Inhibitory Concentration (MIC) estimation. Widest inhibition zone was exhibited by Staphylococcus aureus whereas, Enterococcus faecalis and Salmonella enterica showed the largest MIC values. Antibiofilm activity (%) was determined by using pure culture of L. monocytogenes and S. aureus as positive control, whereas 1, 1 diphenyl-2picrylhydrazyl (DPPH) and 2-2-azinobis-3ethylbenthiazoline-6-sulphonic acid (ABTS) radical scavenging activity was taken as parameter for antioxidant activity. The results showed that with application of REO, biofilm formation of both L.monocytogenes and S. aureus was inhibited by 73.0 and 77.65%, respectively in comparison to their respective controls. Six different concentrations of oil was used for determination of ABTS and DPPH radical scavenging activity and it was ranging from 8.16–51.80% for DPPH whereas ABTS values ranged from 6.81–44.16% for rosemary oil under investigation. It can be concluded that rosemary essential oil possesses potent antimicrobial, antibiofilm and antioxidant activity, and may be used as a natural preservative to extend the storage stability of meat products.