ABSTRACT
Aflatoxin B1 [AFB1] is a toxic metabolite produced by Aspergillus species that contaminates a wide range of agricultural products. This study was designed to develop a rapid and highly sensitive immunoassay method in microarray format for quantitative detection of AFB1 to evaluate the potential of microarray platform for high-throughput screening, which can be beneficial in food and feed industry. Following successful optimization, using an indirect competitive immunoassay in dot blot format, AFB1-bovine serum albumin [AFB1-BSA] conjugate was contact-printed onto 16 isolated subarrays on multi-pad nitrocellulose coated slides; subsequently used in competitive binding assays. Using the aforementioned assay, AFB1 was determined from 15 pg/g to 3.04 ng/g working range with detection limit [LOD] of 1 pg/g. To evaluate assay performance in real food matrices, the authors spiked wheat samples with different concentration of AFB1. After extraction, working ranges of 0.11-4.15 ng/g with detection limit of 30pg/g was determined. Good recoveries [94 +/- 9%] were obtained, demonstrating accurate detection of AFB1 concentrations in wheat samples. Assay procedure completed in 3 hours. The results indicated that the proposed developed assay in microarray format could be used for rapid and sensitive detection of AFB1in wheat samples
Subject(s)
Microarray Analysis , Immunoblotting , Immunoassay , TriticumABSTRACT
Lactobacilli are known as a valuable source of antimicrobial compounds and have a high potential of use in food biopreservation against food related microorganisms. Antimicrobial potency of 63 dairy lactobacilli isolates against four highly important food-related microorganisms were evaluated. In addition, a new way in data organization was introduced, which led to a more informative and rational comparison of indicator microorganisms' susceptibilities to a set of compounds. Correlation of pH and antimicrobial properties was investigated. Microbroth dilution assay was used to evaluate indicator microorganisms' susceptibility to lactobacilli CFCS [cell free culture supernatant]. Results were organized by both the conventional way - demonstrating the minimum inhibitory and lethal concentrations of CFCS - and a new suggested method, representing comparative effectiveness of each CFCS specimen against indicator microorganisms of comparison interest. Susceptibilities of tested strains were in the following order: Escherichia coliO157:H7 > Listeria monocytogenes > Aspergillus parasiticus> Candida parapsilosis. Despite the high susceptibility of L. monocytogenes, it showed the highest resistance to death among the tested microorganisms. Efficiency of Lactobacilli CFCS in killing the tested strains showed the following susceptibility order: E. coli O157:H7 > A. parasiticus> C. parapsilosis> L. monocytogenes. Antimicrobial property was in correlation with the pH value of CFCS. PH had a pronounced impact on susceptibilities of C. parapsilosis and E. coli in pH values of concentrated CFCS lower than 4 and 4.5, respectively. Potency of lactobacilli isolates in growth inhibition of the indicator microorganisms was found promising, and the suggested data organization method provided additional information, leading to more precise comparison of indicator microorganisms
ABSTRACT
Reducing the detrimental effects of free radicals, in biological and food systems by antioxidants, is important, thus providing antioxidants is necessary issue in community health and food safety. The aim of the present study was to determine antioxidant properties of the essential oil and various extracts obtained from summer savory. Summer savory were extracted using different type solvents and chemical composition of hydro-distilled volatile oil from the aerial part of the plant and analyzed by GC/MS. The antioxidant activities were measured by 2, 2'-diphenyl-1-picrylhydrazyl [DPPH°] free radical scavenging and beta-carotene-linoleic acid assays. 32 compounds, which representing 98/92% of the essential oil, were detected as major components: [thymol, carvacrol and terpinene, respectively]. While IC50 for DPPH radical-scavenging activity were 38.46 +/- 0.12, 37.73 +/- 0.17, 30.76 +/- 0.63 microg/mL for water, methanol, and ethanol extracts, respectively, it was 96.15 +/- 0.13 microg/ml for essential Oil. 80.3, 76.25, 74.3 and, 52.46% inhibition were shown for water, ethanol, methanol extracts and essential oil in beta-carotene/linoleic acid assay, respectively. These parameters for BHT were 4.9 +/- 1.9 microg/mL and 88.88% for DPPH and beta-carotene-linoleic acid tests, respectively. According to the results in this study, all treatments comparing with control, displayed strong antioxidant and radical-scavenging properties. The highest radical scavenging effect was observed in ethanol extract. The aqueous extract exhibited the greatest inhibition compared with others. Meanwhile, in both assays the extracts had more antioxidant activity than the essential oil [p<0.05]. It seems the extracts [aqueous and alcoholic] and essential oil, could be considered as a cheap, easily accessible and potential source of natural antioxidants for food and pharmaceutical purposes
ABSTRACT
Health concerns due to adverse effects of chemical preservatives have increased public interest to consuming preservative-free products or product containing natural preservatives such as plant extract and their essential oils. In this study the antibacterial effect of aqueous, ethanolic and methanolic extracts from petal of saffron against the most important foodborne pathogens Salmonella typhimurium, Listeria monocytogenes, E. coli O157: H7, Bacillus cereus and Staphylococcus aureus were evaluated. Disk diffusion method was done to screen bacterial sensitivity. The minimum inhibitory concentration [MIC] of extracts were evaluated by agar dilution and broth microdilution method. The most sensitive strain to extracts was S. typhimurium, and the most resistant strains were S. aureus and E. coli O157:H7. MICs of all extracts were estimated 40 mgml[-1], against all bacteria using agar dilution method. The aqua and methanolic extracts showed antimicrobial activity against all of bacteria by broth microdilution and MIC estimated 40 mgml[-1], however MIC of ethanolic extracts estimated 40 mgml[-1] for L. monocytogenes, S. aureus and B. cereus, while the MICs for S. typhimurium and E. coli O157:H7 were estimated >40 mgml[-1]. The results of this study revealed that the studied extracts might be potential sources of natural antimicrobial agents, and propose their potential application in food system as a natural preservative
Subject(s)
Anti-Bacterial Agents , Foodborne Diseases , Food Preservatives , Disk Diffusion Antimicrobial Tests , Plants, Medicinal , Plant Extracts , Microbial Sensitivity Tests , Plant Oils , Salmonella typhimurium , Listeria monocytogenes , Escherichia coli O157 , Bacillus cereus , Staphylococcus aureusABSTRACT
In order to reduce or eliminate foodborne pathogens or food spoilage agents many research have been done to find natural preservatives. This study was carried out to determine minimum inhibitory concentration [MIC] of lysozyme and Zataria multiflora boiss. essential oil on E. coli 0157: H7 and their sub inhibitory concentration effect on bacterial growth curve. In this study different concentrations of lysozyme [0. 125, 250, 500 and 1000 micro g/ml] and Zataria multiflora boiss. essential oil [0, 0.005, 0.01, 0.02, 0.04 and 0.08%] were used alone and in combination on BHI broth to determine MIC of Zataria multiflora boiss. essential oil and lysozyme with macro dilution and micro dilution methods and effect of sub inhibitory concentrations of them on bacterial growth curve of E. coli 0157: H7. MIC of essential oil in two methods was achieved 0.04% whereas lysozyme in 100 micro g/ml concentration was not able to reduce bacterial growth. Furthermore combination results revealed that high concentration of lysozyme was not able to reduce calculated amount of MIC of essential oil. Sub inhibitory concentration effect of EO and lysozyme showed that their combination result in the increase of lag phase and reduction of bacterial growth. Utilization of EO and lysozyme together did not decrease MIC but combination of them increase lag phase
Subject(s)
Microbial Sensitivity Tests , Foodborne Diseases/prevention & control , Food Preservatives , Escherichia coli , MuramidaseABSTRACT
Application of natural compounds, including essential oils [EOs] and lysozyme is an effective method against growth of bacterial pathogens in foods. Determination of minimum inhibitory concentration [MIC] of lysozyme and Zataria multiflora Boiss. essential oil on L. monocytogenes. In this study different concentrations of lysozyme and Zataria multiflora Boiss. EO were used alone and in combination on BHI broth to determine MIC of Zataria multiflora Boiss. EO and lysozyme with macro dilution and micro dilution methods and effect of sub inhibitory concentrations of them on bacterial growth curve of L. monocytogenes. The minimum inhibitory concentration [MIC] of Z. multiflora Boiss EO was estimated ?0.04 using macro and microdilution. lysozyme at the highest concentration [1000 microg/ ml] was not effective in inhibition of bacterial growth and no MIC value obtained. Combination of EO and Lysozyme decreased the MIC value to%0.02 and 250microg/ mlfor Z. multifloraBoiss. EO and lysozyme, respectively. The results of growth curve analysis showed that combination was effective in increasing the lag phase. Z. multiflora Boiss and lysozyme showed to be effective against bacterial growth and its potential application in food systems may be suggested
ABSTRACT
Z. multiflora Boiss. is one of the Iranian traditional spices and it has antimicrobial effect on the pathogenic bacteria which are agents for some current foodborne intoxications. The present study was conducted to evaluate the antimicrobial activity of Z. multiflora Boiss. Essential oil on Staphylocuccus aureus ATCC 29213. Minimum inhibitory concentration [MIC] and minimum bactericidal concentration [MBC] of Z. multiflora Boiss. essential oil [EO] for Staphylocuccus aureus at 35[degree sign]C, the effect of subihibitory concentrations of EO on growth of bacteria up to 72 hours and also production of entertoxin E [SEE], all at 25 and 35[degree sign]C has been determined. MIC and MBC of EO which have been evaluated in 0.005 - 0.06% [V/V] were 0.03 and 0.04%, respectively. Colony counting during 72h showed that 75%MIC of EO in 72h reduced 3 log [cfu/ml] at 25[degree sign]C and 2, 2 and log [cfu/ml] at 35[degree sign]C in comparison with control culture. Subihibitory concentrations of EO, significantly, decreased the production of SEE at both 25 and 35[degree sign]C in a dose dependent manner. The results showed that Z. multiflora Boiss. essential oil had inhibitory effect on Staphylocuccus aureus and it can be used as a natural preservative in food industry
ABSTRACT
The growing interest in substitution of chemical food preservative with natural ones has fostered researches on plant essential oils and extracts. The purpose of the current study was to evaluate the effect of Zataria multiflora Boiss. essential oil on growth respose, the percent of growth inhibitory and morphology of Penicellium citrinum. Different concentrations of the essential oil [0, 50, 100, 200, 400, 600 ad 1000 ppm] were used in agar dilution method to evaluate growth and spore production parameters. The cultured mold were studied by scanning electron microscope. Values among groups were compared using 1-way ANOVA. It was found that the effect of different concentrations of essential oil on radial growth and sporulation was statistically significant [p<0.05]. The minimum inhibitory concentration [MIC] and minimum fungicidal concentration [MFC] both were 400ppm. According to scaning electron microscopy the treatment with the oil led to alterations in hyphal morphology. Our results suggest that Zataria multiflora Boiss. essential oil can be used as a natural preservative against Pencillium citrinum in foods
Subject(s)
Penicillium/drug effects , Growth , Oils, Volatile , Microbial Sensitivity TestsABSTRACT
Essential oils and their components have antimicrobial effects. They use with spices as flavoring agents all over the world. They have been used safely since ancient times as herbal medicines. Zataria multiflora Boiss. is one of medicinal herbs in Iran and its antimicrobial effects on foodborne pathogens have to investigate in foodstuff. The aim of this study was to determine of the effect of Zataria multiflora Boiss. Essential oil on the growth of Listeria monocytogenes in salted [4%] silver carp. Effect of different concentrations of this Essential oil [0.0%, 0.045%, 0.135%, 0.405%, and 0.810%] on behavior of Listeria monocytogenes was determined by evaluation of the bacterial growth in salted fish fillets. The essential oil in used concentrations had significant inhibitory effect on the growth of Listeria monocytogenes in salted fish during the storage time. The higher concentration until 0.405%, the more significant inhibitory effects on the growth of Listeria monocytogenes [p<0.05] but 0.405% and 0.810% concentrations had no different significant inhibitory effects on the growth of Listeria monocytogenes [p>0.05]. Organoleptical survey showed that the concentrations of the essential oil used until 0.405% not only had no undesirable effect on flavoring but also it improve taste and flavor of salted fish. The result suggested that the Zataria multiflora Boiss. Essential oil can be considered as a natural preservative in salted fish
Subject(s)
Animals , Oils, Volatile , Listeria monocytogenes , Fishes , PhytotherapyABSTRACT
Staphylococcal food poisoning does not result from the ingestion of S. aureus per se, but rather from enterotoxins which are pre-formed within the food. There is no report on effect of Zataria multiflora Boiss. essential oil on enterotoxin production by this microorganism. The aim of this study was to evaluate the effect of different concentrations of Zataria multiflora Boiss. essential oil on enterotoxin production by S. aureus. This study was done as a factorial model using different concentrations of EO [0, 0.005, 0.015 and 0.03%].The bacterial growth was evaluated during 43 days of incubation and enterotoxin production was analyzed using a enterotoxin assay kit. The growth of the organism was completely inhibited by the EO=0.03%. Enterotoxin production was not affected by sub-inhibitory concentration of EO at level of 0.005%, while it was significantly [p < 0.05] inhibited by increasing subinhibitory concentration of EO to 0.015%. The adverse effect of sub-inhibitory concentration of Zataria multiflora Boiss. EO on enterotoxin production by S. aureus, demonstrated in this study, suggests the potential application of this EO as a natural antimicrobial in foods
Subject(s)
Enterotoxins/biosynthesis , Oils, Volatile , Staphylococcus aureus , Bacterial ToxinsABSTRACT
In spite of done improvements in slaughter hygiene and food production techniques, food safety is an important public health issue. Furthermore, the World Health Organization has recently called for a worldwide reduction in the consumption of salt in order to reduce the incidence of cardio-vascular disease. If the level of salt in processed foods is reduced, it is possible that other additives will be needed to maintain the safety of foods. Essential oils are probably one of the natural additives that can use as antibacterial additives. The aim of this study was evaluation of the effect of Zataria multiflora Boiss. essential oil on the growth of Salmonella typhimurium in commercial barley soup. At first, essential oil of Zataria multiflora Boiss. analyzed using GC/MS and the chemical components were identified. Antibacterial activity of Zataria multiflora Boiss. essential oil on the growth of Salmonella typhimurium in commercial barley soup evaluated by using different essential oil concentrations [0.0, 0.005, 0.015 and 0.03%] and two different temperatures [8 and 25°C] during 21 days. Antibacterial activity of Zataria multiflora Boiss. essential oil on the growth of Salmonella typhimurium was statistically significant [p<0.00]. The correlation coefficient of essential oil with log10 of the number of Salmonella typhimurium was -0.402. Zataria multiflora Boiss essential oil probably can used as a proper preservative against some food borne pathogen bacteria in certain foods
Subject(s)
Oils, Volatile , Anti-Bacterial Agents , Hordeum , Food PreservativesABSTRACT
Cuminum cyminum is one of the Iranian traditional spices and it has antimicrobial effect on the pathogenic bacteria which are agents for some current food born intoxications. Probiotics have known as health and immune system booster. Evaluation of antimicrobial effect of mentioned plant essential oil in combination with lactobacillus acidophilus on Staphylococcus aureus in Feta cheese. The essential oil of this plant was obtained by hydrodistillation and analyzed by GC/MS. Effects of different concentrations of this essential oil and lactobacillus acidophilus on Staphylococcus aureus were determined by evaluation of the microorganism growth on the selective media in laboratory, and these were took place in Feta cheese. Results indicated that 0.03 and 0.015 percent of this essential oil have had the highest inhibitory effect on the growth of Staphylococcus aureus and when the mentioned concentrations of the essential oil were used in combination with lactobacillus acidophilus, the counts of the pathogen were decreased significantly bellow its toxic dose in this kind of food product. Results indicated that each one of mentioned concentrations of the essential oil and lactobacillus acidophilus, was significant. The synergistic impact between mentioned concentrations of the essential oil and lactobacillus acidophilus was significant. The antimicrobial effect of Cuminum cyminum in 0.03 percent was higher than its lesser concentrations and with concern to the control group, the synergistic effect between the probiotic and the essential oil is necessary to achieve this inhibitory effect
Subject(s)
Anti-Bacterial Agents , Probiotics , Staphylococcus aureus , Cheese/microbiology , Plant ExtractsABSTRACT
The growing interest in substitution of chemical food preservatives by naturalones has fostered researchs on plantessentiak oils and extracts. In this study effect of different concentrations of Zataria multiflora Boiss. Essential oil [0, 0.005, 0.015 and 0.03%] on Bacillus cereus ATCC 11778, [10[3]cfu /ml], was evaluated using sterilized samples [16 bottles containing 80 ml barley soup] and 4 different incubating temperatures [8, 10, 15 and 25°C] during 21 days. Data analysis was done using two way ANOVA. It was found that effect of different concentrations of essential oil on growth rate of Bacillus cereus ATCC 11778 was statistically significant [p<0.01]. The results suggested that Zataria multiflora Boiss. essential oil can be considered as a natural preservative in some foods
Subject(s)
Oils, Volatile , Hordeum , Plant ExtractsABSTRACT
The infection of food animals to hydatid cyst is a concern from economic and public health stand points. In this survey, the prevalence of hydatid cysts was studied in 547 buffaloes slaughtered at the slaughterhouse in Urmia. Samples from 58 cases [10.6%] were infected to hydatid cysts. The infection rates of lung and liver were 45 cases [77.5%] and 37 cases [63.7%], respectively, while each heart and kidney samples, 1 case [1.7%] was found infected. Also, 24 buffaloes [41.3%] were infected both in lung and liver. However, none of the buffaloes studied had the spleen infected to hydatid cyst. The maximum cysts in the infected lungs and livers were 52 and 81, respectively. The minimum cysts in lungs and livers was 1. The average numbers cysts in the infected lungs and livers were number of 5.11 and 3.87, respectively In the only case, related to heart and kidney, there were 1 and 2 cysts respectively. Considering the prevalence rate, the results obtained from the statistical analysis did not show any significant difference between male and female sexes, whereas a significant statistical relation was observed between the age of buffaloes and the prevalence rate [p<0.05]. The age group above 5 years showed the highest level of infection. In this survey, there was no significant difference in the intensity of infection to hydatid cysts in males comparing to that of females. But a significant difference was found between the intensity of infection in age groups below 2.5 years and the ones above 5 years [p<0.05]. In conclusion, the results revealed high infection to hydatid cyst in Iranian buffaloes, so more attention of related control organizations seems to be needed
Subject(s)
Male , Female , Animals , Buffaloes/parasitology , Abattoirs , Severity of Illness Index , Prevalence , EchinococcusABSTRACT
In this study, the effect of different concentrations of Zataria multiflora Boiss. essential oil [0.00, 0.005, 0.015, 0.03%], temperatures [8 and 25°C] and storage time [up to 21 days] was evaluated in a food model system [Humburger]. The correlation coefficient of different concentrations of zataria multiflora Boiss.essential oil with logarithm of the numbers of E.coli O[157]:H[7] was [-o.528]. It was found that effect of different concentrations of essential oil on growth rate of E.coli O157:H7 was statistically significant [p<0.05]. The correlation coefficient of storage time and logarithm of the number of microorganism used in this study was [0.434], which indicated a decrease in the growth rate when the storage time was increased. The effect of storage time on growth rate was statistically significant [p<0.05]. In addition the correlation coefficient of storage temperature with logarithm of the number of bacterium was [0.500]. In other words, decreasing the storage temperature [from 25°C to 8°C] resulted in the decrease of the growth rate of the microorganism [p<0.05]
Subject(s)
Oils, Volatile , Temperature , Colony Count, Microbial , Meat Products/microbiology , Food Contamination , Food HandlingABSTRACT
Molds are important spoiler of food material and have potential of mycotoxin production. The adverse side effects of chemical preservatives have caused that research focused on use of naturally occurring compound, especially essential oils [EOs], for inhibition of mold growth. Essential oils are natural compounds containing terpenic mixtures that have antimicrobial and antioxidant properties. Zataria multifloro Boiss., a domestic aromatic plant of Iran, has different effect such as antispasmodic and antibacterial. In this study effect of Z. multiflora Boiss. Essential oil on growth and spore production by Aspergillus flavus and its morphological alteration action were investigated. After extraction of essential oil with steam distillation method, it was analyzed by GC-MS. Evaluation of essential oil effect on growth and spore production carried out by agar dilution method. For SEM evaluation, mold cultured on PDA was fixed with osmium tetroxide and blocks of agar were coated with gold and observed by scanning electron microscope. Effect of EO on growth and spore production by A. flavus was significant in all concentrations studied. MIC and MFC values were 400 and 1000 ppm, respectively. SEM analysis showed excessive sporulation of mold culture in absence of EO while sporulation of culture containing EO was very sparse. Morphological changes such as irregular surface with many folds and distortion of hyphae were seen in cultures treated with EO. Inhibitory effect of Z. multiflora Boiss. Essential oil demonstrated in this study candidate this EO as a substitution of chemical preservatives
Subject(s)
Plant Oils , Aspergillus flavus/drug effects , Chromatography, Supercritical Fluid , Phytotherapy , Oils, VolatileABSTRACT
Thyme [Zataria multiflora Boiss] is one of the Iranian traditional spice and it has antimicrobial effect on the pathogenic bacteria which are agents for some current food borne intoxications. Evaluation of antimicrobial effect of mentioned plant essential oil on Staphylococcus aureus in Feta cheese. The essential oil of this plant was obtained by hydrodistillation and analyzed by GC/MS. Effects of different concentrations of this essential oil on Staphylococcus aureus were determined by evaluation of the microorganism growth on the selective media in laboratory, and these effect on the growth of Staphylococcus aureus and when the mentioned concentrations of the essential oil were used in combination with cheese starter culture, the counts of the pathogen were decreased significantly below its toxic dose in this kind of food product. The antimicrobial effect of Zataria multiflora Boiss. in 300 ppm was higher than its lesser concentrations and with concern to the control groups, the synergistic effect between the starter and the essential oil is necessary to achieve this inhibitory effect
Subject(s)
Staphylococcus aureus , Anti-Bacterial Agents , Cheese/microbiologyABSTRACT
In this study, samples of farm shrimp species Paeneus indicus obtained from different stages of hatchery and rearing period and subsequent marketing, water and sediments of rearing farms and marine shrimp species Paeneus semisulcatuswere analysed for Vibrio spp. according to the methods described by American Public Health Association. The identified Vibrio species were Vibrio alginolyticus, V. parahaemolyticus [Kanagawa positive] and V. fluvialis. The results and detection of V. parahaemolyticusKanagawa positive [even in low proportion] in this study suggest a probable risk for health of people consuming raw or under cooked shrimp. Therefore it is recommended to pay attention to post harvest handling e.g. washing the shrimp with fresh water containing 2-7 ppm chlorine and freezing at -40 C and adequate cooking to safeguard public health. Key words:cultivated and marine shrimp, Vibrio spp., Iran
Subject(s)
Animals , Fisheries , Vibrio , Marine BiologyABSTRACT
About 30% of people in developed countries at least once a year experience a food borne disease. Therefore, there is a need for new methods to prevent the growth of food borne pathogens or decrease the number of them in foods. One of the methods is to use plant essential oils as antimicrobial additives in foods. To establish the usefulness of plant essential oils, they must be evaluated alone or in combination with other preservation factors [such as temperature, storage time and ...] first in the laboratory models and then in food model systems. The aim of this study was to determine of the effect of Zataria multiflora Boiss. essential oil on the growth of Staphylococcus aureus in commercial barley soup using different essential oil concentrations [0.0, 0.005, 0.015 and 0.03%] and temperatures [8 and 25°C] during 21 days. The effect of different concentrations of essential oil on growth rate of Staphylococcus aureus was statistically [ANOVA] significant [p<0.01]. The correlation coefficient of Zataria multiflora Boiss. essential oil with log l0 of the number of Staphylococcus aureus was -0.588. The effect of storage time on growth rate of the organism was also statistically [ANOVA] significant [p<0.05]. The correlation coefficient of storage time with log l0 of the number of microorganism used in this study was -0.2 which showed a decrease in the growth rate of the organism when the storage time was increased. In addition the correlation coefficient of storage temperature with log l0 of the number of Staphylococcus aureus was 0.449. In other words, by decreasing the storage temperature [from 25 to 8°C], the decreasing of the growth rate of the microorganism was observed. The effect of different storage temperatures and their interaction with different concentrations of essential oil on growth rate of Staphylococcus aureus was also statistically [ANOVA] significant [p<0.01]. The results suggested that the Zataria multiflora Boiss essential oil can be considered as a natural preservative in some foods
Subject(s)
Plant Oils , Food Preservation , Staphylococcus aureus , Anti-Infective Agents , Preservation, Biological , TerpenesABSTRACT
The growing interest in substitution of chemical food preservatives, both antimicrobials and antioxidants, by natural ones has fostered research on the vegetable sources and screening of plant extracts and essential oils in order to identify acceptable natural alternatives. In order to evaluate the antimicrobial effects of different essential oils on food-borne pathogens and/or food spoilage microorganisms, first we should study them in laboratory models and then in foods. In this study Log probability percentage of growth [Log P%] of Bacillus cereus in Brain Heart Infusion broth as affected by different concentrations of Zataria multiflora Boiss. essential oil [0.0, 0.005, 0.015, 0.03 and 0.045%] during 43 days of storage at three different temperatures [30,20 and 10°C] was investigated. The Log P% of B. cereus was affected significantly [p < 0.05] by different concentrations of the essential oil, storage temperatures and combined effects of them. The maximum Log P% of B. cereus [and the day to reach the maximum probability of growth] in BHI broth with 0% essential oil at 30, 20 and 10°C were 1.46 [1], 1.46 [3] and 0.15 [28], respectively. While in BHI broth with 0.005, 0.015, 0.03 and 0.045% essential oils were 1.46 [1], -1.4693 and -3.54 [22]; 1.46 [1], 1.46 [10] and -3.85 [25]; 1.46 [16], 1.46 [16] and -4.45 [>43] and 0.15 [13], -1.85 [7] and -4.54 [>43], respectively. According to our results the Log P% of B. cereus was significantly decreased [P<0.05] by little increase of essential oil concentrations in this study. This inhibitory effect of the essential oil was also significantly increased [P<0.05], when the temperature decreased and we did not observe any growth [Log P% = -4.54] in broth with 0.03 and 0.045% essential oil during 43 days storage at 10°C