Chemical composition and evaluation of antimicrobial properties of Rosmarinus officinalis L. essential oil
Preservatives used in the food industry are undergoing increasing scrutiny and reappraisal. There is therefore a renewed interest in the antimicrobial properties of herbs and spices. Rosemary (Rosmarinus officinalis L.) belonging to the Lamiaceae family, is a pleasant-smelling perennial herb. The antimicrobial activities of the R. officinalis oil against Leuconostoc mesenteroides (PTCC1591), Lactobacillus delbruekii (PTCC1333), Saccharomyces cerevisia (PTCC5269) and Candida krusei (PTCC 5295) were determined. The results indicate that among the tested microbes, the essential oil had a stronger inhibitory effect on the bacteria as compared to yeasts. Minimum inhibitory concentration (MIC) values for bacteria L. mesenteroides, L. delbruekii, S. cerevisia and C. krusei ranged between 0.5 and 1.5 mg/ml. The oil was analyzed by GC and GC/MS. The major components of R. officinalis oil were 1,8-cineole (23.14%), camphor (12.35%), α-pinene (9.87%), β-pinene (6.10%), borneol (5.61%), camphene (5.58%) and α-terpineol (4.30%), respectively. These results indicate the latent potency of essential oil of R. officinalis as a natural preservative in food products against L. mesenteroides, L. delbruekii, S. cerevisia and C.krusei.
Key words: Rosmarinus officinalis L., essential oil, chemical composition, antimicrobial properties.