Chemical composition and antimicrobial effects of essential oils in some spices

In this thesis, it was aimed to determine the essential oil quantities and chemical contents of some spice species (Thyme, Laurel, Clove, Garlic, Cumin, Rosemary, Coriander, Cinnamon, Black Pepper, Sage, Anise, Basil, Fennel) consumed for food purposes. It is also aimed to determine the antimicrobial effects of these oils agains a number of microorganisms (Bacillus cereus, Bacillus subtilis, Escherichia coli, Clostridium perfringens, Enterobacter aerogenes, Salmonella typhimurium, Staphylococcus aureus, Lactobacillus fermentum, Listeria monocytogenes, Candida albicans, Aspergillus brasiliensis) that spoil some pathogens and foods. Microbial load of some raw spices were determined and the spices that were subjected to steam sterilization at various temperatures. The essential oils of the sterilized spices were obtained by distillation method. The components and the proportions of the essential oils were determined by gas chromatography. And their antimicrobial effects were investigated against the test microorganisms using disc diffusion method. In addition, the MIC (minimum inhibitory concentration) values of essential oils were determined. As a result, it was determined that all essential spices used in the study have antimicrobial effect. The order of antimicrobial effect was determined as Thyme, Sage, Cinnamon, Anise, Fennel, Cumin, Basil, Rosemary, Laurel, Coriander, Black Pepper from most effective to low.