Kekik ve mercanköşk diğer yağlara göre daha yüksek antimikrobiyal aktivite gösterirken, her iki mikroorganizmaya karşı en yüksek antimikrobiyal aktiviteyi. Pazarbasi, B., Yilmaz, M., Türkiye Kosullarinda Üretimi Yapilan Spirulina platensis’ in Çesitli Ekstraktlarinin Antimikrobiyal Aktivite Kapasitesinin Belirlenmesi. antimikrobiyal aktivite, antioksidan aktivite, fenolik madde. Özet: Bu çalışmada Türkiye’nin Doğu Akdeniz Bölgesi’nden toplanan Tornabea.
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Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated. Please use this identifier to cite or link to this item: Show full item record. Preservation of food materials from spoilage, mainly by microbial activity, during production, storage and marketing is an important issue in the food industry.
To achieve this purpose the food industry has used different physical and chemical methods which diminish microbial growth or inhibit microorganisms and prevent or delay. In spite of modern improvements, food safety is an increasingly important public health issue. There is therefore still a need for new methods of reducing or eliminating food borne pathogens.
There are also new concerns about chemical preservatives due to increasing aantimikrobiyal of many respiratory illnesses.
However, the increased demand for safe antimikrobiyao natural food, without chemical preservatives, provokes many researchers to investigate the antimicrobial effects of natural compounds. Numerous investigations have confirmed the antimicrobial action of essential oils. Essential oils, known as volatile oils, are complex mixtures of aromatic and volatile constituents which are obtained by such as distillation, cold pressing and maceration. The main advantage of essential oils is that they can be used in any food and are generally recognized as safe GRAS.
Although, they are GRAS, the application of essential oils is aktivitd because of organoleptic changes in food. However, the stereochemistry, lipophilicity and other factors affected the biological activity of these compounds which might be altered positively or negatively by slight modifications. Essential oils can comprise more than sixty individual components.
The phenolic components are chiefly responsible for the antibacterial properties of essential oils. There is some evidence that minor components have a critical part to play in antibacterial activity, possibly by producing a synergistic effect between other components.
A number of essential oil components has been identified as effective antibacterials, e. They affect microbial cells by various antimicrobial mechanisms, including attacking the phospholipid bilayer of the cell membrane and distrupting enzyme systems.
Hydrophobicity of essential oils and their components enables them to partition in the lipids of the bacterial cell membrane, disturbing the structures and rendering them more permeable.
Leakage of ions and other cell contents can then occur. Extensive loss of cell contents or the exit of critical molecules and ions will lead to death. In a study, how mustard essential oil affected the cell membrane of Escherichia coli O H7 and Salmonella typhi was investigated.
Intracellular pH and ATP concentration and the release of cell constituents were measured when mustard essential oil was in contact with E. The treatment with mustard essential oil affected the membrane integrity of bacteria and induced a decrease of the intracellular ATP concentration.
Also, the extracellular ATP concentration increased and a reduction of the intracellular pH was observed in both bacteria. A significantly higher release of cell constituent was observed when both bacteria cells were treated with mustard essential oil. Electronic microscopy observations showed that the cell membranes of both bacteria were apparently damaged by mustard essential oil.
The apparent antimicrobial efficacy of plant origin antimicrobials depends on factors such as the method of extracting essential oils from plant material,the part of a plant where the essential oil is extracted,type of solvent, volume of inoculum, growth phase, culture medium used, concentration of essential oil, temperature, oxygen and intrinsic or extrinsic properties of the food such as pH, fat, protein, NaCl, and physical structure of food.
It is also known that chemical composition of essential oils from a particular plant species can vary according to the geographical origin and harvesting period. Results showed that planting space had significant effect on plant diameter and very significant effect on other measured parameters except oil content, which was not significant.
Time of harvest had significant effect on yield of fresh herbage, content of oil and content of carvacrol.
Browsing by Subject “Antimikrobiyal Aktivite”
Its effect on other parameters was very significant except dry herbage and oil yield. The maximum yield of dry and fresh herbage, yield and content of oil and thymol yield were obtained beginning of blooming stage. Tests of antimicrobial activity can be classified as diffusion and dilution methods.
Diffusion antimikrobiyla can be classified as disc diffusion and agar well diffusion methods while dilution method can be classified as agar dilution and broth dilution methods. In broth dilution studies a number of different techniques exist the most used methods are that of optical density OD turbidity measurement and the enumeration of colonies by viable count.
The obtained results are more sensitive than agar dilution method.
The principles and practice of these test are explained in the literature but it appears that no standardised test has been developed for evaluating the antibacterial activity of essential aktvite against food-related microorganisms. Applying different methods to determine antimicrobial aotivite of an essential oil cause to be obtained different results.
However outcome of a test can be affected by factors such as the method used to extract the essential oil from plant material, the volume of inoculum, growth phase, culture medium used, pH of the media and incubation time and temperature. Therefore comparison of published data is complicated. Dilution methods are usually used to obtain minimum inhibitory concentration MIC and minimum bactericidal concentration MBC.
Browsing by Subject “Antimikrobiyal Aktivite”
MIC is defined as the lowest concentration of the essential oil which inhibits bacterial growth. Antimikrobial is defined as concentration where The aim of this study was to determine the antimicrobial activity of some essential oils dillweed, cardamon, aktovite, thyme, cumin, origanum, fennel and ginger essential oils against Escherichia coli and Staphylococcus aureus and to determine the MIC and MBC antimikrobiysl of the selected essential antimikrobiya.
In this study, dillweed, cardamon, basil, thyme, cumin, origanum, antkmikrobiyal and ginger essential oils were studied for their antimicrobial activity against Aktivte coli and Staphylococcus aureus by agar well diffusion method. The activity of dillweed, cardamon, thyme, cumin and origanum essential oils against E. Antimikrpbiyal the contrary, no antibacterial activity was observed for basil, ginger and fennel essential oils against E.
Thyme and origanum essential oils showed higher antimicrobial activity than the other essential oils. However, origanum essential oil showed the highest inhibitory activity against both bacterial species tested. The obtained inhibition diameters of essential oils against E. Generally both of the tested microorganisms were sensitive to many of the essential oils. However, most studies investigating the antimikrobkyal of whole essential oils against food spoilage organisms and food borne pathogens agree that, generally, essential oils are slightly more active against gram-positive than gram-negative bacteria.
Gram-negative bacteria are less sensitive to the antimicrobials because of the lipopolysaccharide outer membrane of this group, which restricts diffusion of hydrophobic compounds.
In this study the results show that gram-negative E. But, this does not mean that gram-positive bacteria are always more susceptible. In the second part of this study 4 essential oils thyme, cumin, cardamon and origanum essential oils which showed antimicrobial activity against Antlmikrobiyal. Inhibitory effect of these selected essential oils were monitored during incubation period 0; 2; 4; 6; 8; 10; 12; 18, 20; 22 and 24 h and the bacterial growth was determined by measuring optical density OD at nm.
Microdilution method was used to determine MIC. The MIC was determined by comparing the turbidity of the essential oil added well with the turbidity of negative control added well.
The concentration of essential oil which had the same turbidity with negative control was determined as MIC and it was corroborated by OD measurement.
However, Antmiikrobiyal values of cumin, cardamon and origanum essential oils which were obtained by visual turbidity measurement differed from MIC values which were obtained by microplate assay. The obtained MIC values against E. The MIC values found for microplate assay was always lower that those found in turbidity measurement because of its sensitivity. In this method obtained MIC values of E. MBC values of thyme and origanum essential oils against E. Depends on the OD measurement results, for all the tested oils, the MBC values were equivalent to the MIC values, confirming their microbicidal effects.
Cumin and cardamon showed the lowest antimicrobial effect against E.