Inhibitory effects of six Turkish thyme‐like spices on some common food‐borne bacteria (Short communication)

It is recognized now that spices and herbs may fulfill more than one function in foods to which they are added. In addition to imparting flavour, certain spices prolong the storage life of foods by a bacteriostatic or bactericidal activity. Being natural foodstuffs, they appeal to consumers who tend to question the safety of synthetic food additives. Antimicrobial properties of several spices and essential oils have been documented [1, 2]. Less attention has been devoted to investigations of antibacterial effects of the leafy spices or herbs. Recent researches have indicated that the antimicrobial factor of spices resides in the essential oil and/or oleoresin fraction [3]. Of herbs, oregano and thyme were generally found to be the most inhibitory and were considered to be among the most actives of the tested spices and their essential oils. Thymol and carvacrol are the two main phenolic constituents of both oregano and thyme oils [4]. The antimicrobial effects of several oregano and thyme species and their essential oils or components on some food‐borne bacteria have been confirmed [5–12]. But, many Labiatae spices (Origanum, Thymus, Satureja etc.) contain thymol and/or carvacrol as the main components in different percentages [13–15]. In addition, several plants are classified as „oregano”︁ the various genera and species differing significantly in aromatic quality and chemical composition. The designations are so confused that it is extremely difficult to establish just which botanical entity is involved [14–16]. The object of this work was to study and compare the effects of 6 Labiatae leafy spices used as thyme from wild growing plants in different regions of Turkey on growth of bacteria in culture media, using organisms known to cause food spoilage or food‐borne illnesses.