Variability of Satureja cuneifolia Ten. essential oils and their antimicrobial activity depending on the stage of development

The essential oils obtained from Satureja cuneifolia Ten. harvested in the central part of Dalmatia at three ontogenetic stages were evaluated for their chemical composition and antimicrobial activity against food pathogens. The GC/MS analyses allowed 32 compounds to be determined; the main constituents of the essential oils were linalool (18.2-17.2%), carvacrol (16.0-5.0%), p-cymene (14.8-4.0%), α-pinene (12.0-5.8%) and limonene (11.0-1.8%). The compounds linalool and borneol appeared to be relatively constant but carvacrol, limonene and α-pinene showed variability during the growth cycles. The oils had a broad-spectrum antimicrobial activity against food pathogens in broth microdilution bioassays. Maximum activity was observed against the yeast Candida albicans, the Gram-negative bacteria Escherichia coli, Salmonella typhimurium and Proteus mirabilis and the Gram-positive bacteria Staphylococcus aureus and Bacillus cereus. The essential oils showed good antibacterial effects against E. coli with a minimum inhibitory concentration of 0.06% and a minimum bactericidal concentration of 0.12% during the flowering stage. These inhibitory effects are interesting in relation to the prevention of microbial contamination in many foods and, therefore, essential oils of S. cuneifolia could be used as substitutes for synthetic antimicrobial compounds.[PUBLICATION ABSTRACT]