Growth Inhibition of Pathogenic Bacteria and Some Yeasts by Selected Essential Oils and Survival of L. monocytogenes and C. albicans in Apple–Carrot Juice Reyhan Irkin 1 and Mihriban Korukluoglu 2 Abstract Food safety is a fundamental concern of both consumers and the food industry. The increasing incidence of foodborne diseases increases the demand of using antimicrobials in foods. Spices and plants are rich in essential oils and show inhibition activity against microorganisms, which are composed of many com- pounds. In this research, effects of garlic, bay, black pepper, origanum, orange, thyme, tea tree, mint, clove, and cumin essential oils on Listeria monocytogenes AUFE 39237, Escherichia coli ATCC 25922, Salmonella enteritidis ATCC 13076, Proteus mirabilis AUFE 43566, Bacillus cereus AUFE 81154, Saccharomyces uvarum UUFE 16732, Kloeckera apiculata UUFE 10628, Candida albicans ATCC 10231, Candida oleophila UUPP 94365, and Metschnikowia fructicola UUPP 23067 and effects of thyme oil at a concentration of 0.5% on L. mono- cytogenes and C. albicans in apple–carrot juice during þ48C storage (first to fifth day) were investigated. Strong antibacterial and antifungal activities of some essential oils were found. Thyme, origanum, clove, and orange essential oils were the most inhibitory against bacteria and yeasts. Cumin, tea tree, and mint oils inhibited the yeasts actively. It is concluded that some essential oils could be used as potential bio- preservatives capable of controlling foodborne pathogens and food spoilage yeasts. Introduction A romatic plants had been used since an- cient times for their preservative and me- dicinal properties, and to impart aroma and flavor to food. Essential (volatile) oils from ar- omatic and medicinal plants have been known since antiquity to possess biological activity, no- tably antibacterial, antifungal, and antioxidant properties. Essential oils are natural, complex, multicomponent systems composed mainly of terpenes in addition to some other nonterpene components (Edris, 2007; Fu et al., 2007). Bacterial and fungal infections pose a greater threat to health, most notably in immunocom- promised subjects; hence, cheap and effective antimicrobial agents are needed. The essential oils can be used as growth inhibitors of food- borne and food spoilage microorganisms (Fisher and Phillips, 2008; Sharef et al., 2008). Re- searchers are interested in biologically active compounds isolated from plant species for in- hibiting pathogenic microorganisms because they have built up resistance to antibiotics. The antimicrobial activity of essential oils is assigned to a number of small terpenoid and phenolic compounds such as carvacrol, thymol, citral, eugenol, 1–8 cineole, limonene, pinene, linalool, and their precursors. Differences in the antimi- crobial activity should be attributed to their 1 Susurluk College, Balikesir University, Balikesir, Turkey. 2 Department of Food Engineering, Uludag University, Bursa, Turkey. FOODBORNE PATHOGENS AND DISEASE Volume 6, Number 3, 2009 ª Mary Ann Liebert, Inc. DOI: 10.1089=fpd.2008.0195 387