INACTIVATION OF ST. AUREUS AND ESCHERICHIA COLI BY ESSENTIAL OIL FROM SAGE (SALVIA SPECIES) IN TELEMEA CHEESE

ABSTRACT

Salvia species are parts of the daily routine of many communities in different regions of the world (Southern and Central Europe, North America, Middle East, etc.). Many research studies show a strong correlation between the concentration of some biologically active substances such as terpenoids, alkaloids, polyphenols and their antimicrobial action. The presence of these chemical compounds resulting from the secondary metabolism of the plant has determined that sage is of great interest to the food industry and in particular to cheese industry. In this study, antimicrobial property of essential oils of S. sclarea and S. officinalis against Staphylococcus aureus and Escherichia coli in ‘Telemea’ cheese were investigated. The effect of the addition of salvia species essential oils at concentrations of 0.0%, 0.05%, 0.1%, 1.5% and 2.0% on the pH value, microbiological and sensory properties of ‘Telemea’ cheese was also evaluated during 28 days of aerobic storage at 4±1°C. Identification of bioactive compounds and chemical composition of slavia essential oils were done by comparison of retention indices and the mass spectra with those in NIST libraries using GC-MS analysis. The results obtained showed that essential oils applied at concentrations of 0.46 and 0.92 mg/mL respectively, which were defined as the MICs, exhibited inactivation activity against Staphylococcus aureus and Escherichia coli in the in vitro assays. The population of target bacteria present in ‘Telemea’ cheese samples was decreased (p ≤ 0.05) when the two type of essential oils were added at concentrations mention above, during the one month storage period. The experimental results show that essential oils obtained from different salvia species could be successfully applied in the production of ‘Telemea’ cheese as natural inactivators for food pathogens.

Keywords: Sage (Salvia species), essential oils, antimicrobial activity, Telemea cheese