[Antimicrobial effect of garlic essential oil [Allium sativum L.] in combination with chitosan biodegradable coating films]

Background: Herbal compounds like Garlic essential oil have antimicrobial and antioxidant properties. They could be effective in microbial control of inside contents when combined by natural and biodegradable coating films such as Chitosan and result in strengthened effects

Objective: Antimicrobial effect increase by using Garlic essential oil in Chitosan film for packaging a food stuff for instance was aimed to be investigated

Methods: Chitosan film was prepared by casting method. Glycerol as plasticizer and tween80 as emulsifier were used with different levels of garlic essential oil [0, 0.5, 1 and 2%]. Then homogenization and molding were performed. After packaging the food stuff with various kinds of films and storage in 4c microbial tests were conducted in days 0, 2, 4, 7, 10 and 14. Statistical analysis was performed with SPSS software

Results: Controls showed a significant difference [P?0.05] for Total Count, Coliform, Staphylococcus aurous and Sychrotrophs when compared with samples packaged with different chitosan films. At the end of the study, Total count in those samples covered with chitosan film containing 2, 1 and 0.5% garlic essential oil was reduced by 1.5, 1.1 and 1 log compared with control respectively

Conclusion: Garlic essential oil addition showed a significant synergistic effect in microbial inhibition with packaging by Chitosan films. Therefore, this combination could be used in future to extend the shelf life of food stuff and may also drug materials

Detection of cytolethal distending toxin [cdt] Genes in Campylo-bacterjejuni and Campylobacter coli isolated from the intestinal of commercial broiler chickens, turkey and quail of Iran

Campylobacter jejuni and Campylobacter coli are zoonotic bacteria which are frequently associated with human diarrhea. Sharing of the cytolethal distending toxin [cdt] genes in Campylobacter is common and is considered species specific. In this study we focused on detecting the presence of cdt gene in C. jejuni and C. coli isolated from broilers, turkeys and quails of Iran. Cecal samples were randomly collected from 240 broiler chickens, 100 meat type turkeys and 100 quails after slaughtering. We used PCR as a method for detecting cdt genes. In broilers, 93% of 58 C jejuni positive samples possessed cdt gene and in all cases the three different subunits of cdt genes were present. However, only 56% of 14 C. coli isolates in broilers had contained cdt genes, while one fourth having all three subunits present. In turkeys, around 65% of 34 C. jejuni positive samples had cdt gene present with 38% possessing all three subunits of cdt genes. But all 5 C. coli isolates had all three subunits cdt gene. In quails, 67% of 30 C. jejuni positive samples were identified by cdt gene, 20% of those possessed all three gene subunits. On the other hand, all 28 C. coli isolates of quails had cdt gene present while 36% of those held all three gene subunits. Our data is indicating the isolation, culture and cdt PCR amplification approaches in this study seemed to be efficient. However, the presence of different variation of Campylobacter cdt gene types in our sample isolates signifies the necessity of further functional gene studies to elucidate which gene type combinations result in encoding effective toxins

Encapsulation of green tea extract in nanoliposomes and evaluation of its antibacterial, antioxidant and prebiotic properties

Background: The application of natural compounds including green tea extract [GTE] in food and pharmaceutical industries is limited. Encapsulation in nanoliposomes could be used as a delivery system to protect these compounds during processing and storage

Objective: In this study encapsulation of green tea extract in nanoliposomes and evaluation of its antibacterial, antioxidant and prebiotic properties were evaluated

Methods: GTE was encapsulated in liposomes by thin film layer method and reached to nanoscale with sonication. The prebiotic activity of 1% nanoliposomal GTE was evaluated on the growth of lactobacillus casei and bifidobacterium lactis in MRS broth medium. Furthermore, the antioxidant activity of nanoliposomal GTE was estimated by DPPH assay. The antibacterial activity of nanoliposomal GTE against Bacillus cereus [ATCC11778], Salmonella typhimurium 138 phage type 2, E. coli O[157]: H[7] and Listeria monocytogenes [ATCC19118] was determined using well diffusion technique

Results: The mean diameter of nanoliposomes was about 44.7 +/- 1.9 nm and had 0.203 +/- 0.014 polydispersity index. Entrapment efficiency of nanoliposomal GTE under the optimum conditions was 97%. Antibacterial activity of GTE was significantly increased after encapsulation in nanoliposomes. The strongest antibacterial activity of nanoliposomal GTE was seen against listeria monocytogenes with an inhibition zone of 16.2 mm while E. coli was the most resistance strain with an inhibition zone of 14 mm. Furthermore, the antioxidant activity of GTE was significantly increased after nanoliposome encapsulation since the IC[50] value of nanoliposomal GTE was decreased to 1.78 microg ml[-1]. Moreover, addition of 1 % nanoliposomal GTE enhanced the growth rate of Lactobacillus casei and Bifidobacterium lactis to a significant extent

Conclusion: Nanoencapsulation effectively enhanced beneficial properties of GTE

[ combined effect of lysozyme and zataria multiflora essential oil on vibrio parahaemolyticus]

Various studies have been conducted to show the effects of essences and enzymes on foodborne pathogens in culture media. The aim of this study was to determine the effect of Zataria multiflora Boiss. essential oil and lysozyme alone and in combination on preventing growth of Vibrio parahaemolyticus in culture media. In this study, the MIC of Zataria multiflora Boiss. essential oil and lysozyme, together and alone, on Vibrio parahaemolyticus, was determined by using macro and microdilution methods. The MIC of Zataria multiflora essential oil determined 0.01% and 0.02% by using macro and microdilution methods, respectively and lysozyme at 1000 mg/mL concentration could not inhibit the growth of V. parahaemolyticus. According to the results of current study, Zataria multiflora essential oil showed better results in comparison with lysozyme, moreover Applying lysozyme and essential oil together did not decrease MIC, but extended the latent phase of V. parahaemolyticus, which considered an important factor in microbiology

[ study on the effects of garlic essential oil on growth curve and TDH toxin production of vibrio parahaemolyticus]

Vibrio parahaemolyticus causes acute gastroenteritis associated with the consumption of contaminated raw or under cooked seafood. The virulence of vibrio parahaemolyticus is initially attributed to the production of a thermostable direct hemolysin [TDH]. The survey of different concentrations of garlic essential oil [Allium sativum] on MIC, MBC, growth curve and production of TDH toxin of vibrio parahaemolyticus. The effects of garlic essential oil at concentrations of 0, 0.005, 0.015, 0.03 and 0.045% on the MIC, MBC, growth curve and production of TDH toxin of vibrio parahaemolyticus were studied in BHI model. MIC and MBC of garlic essential oil was estimated 0.03%. The essential oil showed significant effect on toxin production, Titers of TDH production in 0 and 0.005% were 1/256 comparing to 1.64 in 0.015% concentration of EO. Concentrations of 0.005 and 0.015% of garlic essential oil reduced the bacterial growth rate significantly [p<0.05] compared to the control group. Garlic essential oil showed to be effective against bacterial growth and production of TDH toxin. Its potential application in food systems may be suggested

[Effect of Zataria multiflora boiss. essential oil on growth curve and shigatoxin 2 production of enterohemorrhagic Escherichia coli O157:H7]

Zataria 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 Zataria multiflora Boiss. Essential oil on Escherichia coil 0157:H7. Minimum inhibitory concentration [MIC] and minimum bactericidal concentration [MBC] of Zataria multiflora Boiss. Essential oil [EO] for Escherichia coil 0157:H7 at 35°C, the effect of subinhibitory concentrations of EO on growth curve of bacteria up to 24 hours at 25 and 35°C and also production of shigatoxin 2 [Stx2], at 35°C has been determined. MIC and MBC of EO which have been evaluated were 0.04 and 0.06%, respectively the effect of subinhibitory concentrations of EO on bacterial growth curve during 24 hours has been determined by spectrophotometer device at 25 and 35°C and also production of shigatoxin 2 [Stx2], at 35°C has been determined. Subihibitory concentrations of EO, significantly, decreased the production of Stx2 at 35°C in a dose dependent manner. The results showed that Zataria multiflora Boiss. Essential oil had inhibitory effect on Escherichia coli 0157:H7 and it can be used as a natural preservative in food industry

Antibiotic residues and aflatoxin M1 contamination in milk powder used in Tehran dairy factories, Iran

The presence of aflatoxin M1 [AFM1] and antibiotic residues in milk and milk products is a public health concern. Milk and milk powder have the potential for introducing AFM1 and antibiotic into human diet. In recent years, milk powder has been used on a large scale in dairy factories. Consequently, antibiotic residues and aflatoxin contamination control in these products has gained importance. The aim of this survey was to determine the level of beta-lactam and tetracycline antibiotic residues and also AFM1 contamination of milk powder used in Tehran dairy factories. During 12 months [September 2011 to September 2012], 240 samples of milk powder were collected from ten Tehran dairy factories. All samples were analyzed for the presence of AFM1 using ELISA technique. In addition, antibiotic residues were determined by BetaStar Combo test, a rapid assay for both beta-lactam and tetracycline antibiotics. The samples depicted positive results i.e. 30% and 17.5% for beta-lactam and tetracycline antibiotics, respectively. Also, AFM1 was found in 155 cases [64.6%] with an average concentration of 29.85 +/- 18.99 ng/ L. The results showed the milk powder used by dairy factories is safe in respect of AFM1 contamination and antibiotic residues in Tehran

[Effects of Zataria multiflora boiss. essential oil and acetic acid on thermostable direct haemolysin production of Vibrio parahaemolyticus]

Consumption of contaminated seafood with Vibrio parahaemolyticus results in gastroenteritis in consumer. Thermostabledirecthaemolysin is one of the major virulence factors of this emerging pathogen which has an important role in its pathogenicity. The objective of this study was to evaluate the effect of Zataria multiflora Boiss. essential oil and acetic acid on the production of TDH toxin of Vibrio parahaemolyticus in subinhibitory concentrations of these preservatives. The toxin production under specific condition including the combination of different concentrations of the essential oil [0, 0.005, 0.015, 0.03 and 0.045%], pH values [5.5, 6.5 and 7.5] modified with acetic acid and 3 incubation temperatures[8, 25 and 35[degree sign]C]in BHI broth medium was studied and the number of the bacteria have been counted and the toxin production has been evaluated after the growth of the organism and subsequent turbidity in the medium using the KAP-Rpla commercial kit. Toxin titerproduced in a broth with pH value of 7.5 and 35[degree sign]C and in the absence of essential oil was 1/256 while it was 1/32 in the same condition and with the presence of 0.015% essential oil. Also the titer of this toxin in 25[degree sign]C and pH of 6.5 equals 1/256 while with adding the 0.015% ofZataria multiflora Boiss. essential oil, It reduced to 1/3. According to the results the essential oil in combination with different pH values and incubation temperatures has a decreasing effect on the toxin production of Vibrio parahaemolyticus. It suggests that further studies with the same conditions as current study in a food model is needed to confirm the positive effect of these natural preservatives

[Chemical composition of summer savory [Satureja hortensis L.] essential oil and comparison of antioxidant activity with aqueous and alcoholic extracts]

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

[ survey of the effect of Cuminum cyminum L. essential oil on the growth of Bacillus cereus in a food model system]

Bacillus cereus is a gram positive and spore-forming bacteria that often associated with food products such as meat, vegetables, soup, rice, and milk and other dairy products. 1 - 20% of total outbreaks of food intoxication in the world are caused by Bacillus cereus. There is an increasing interest in the use of plant-derived antimicrobial compounds as natural preservatives for foods; such as Cuminum cyminum L. essential oil that inhibition of the growth of several pathogens by it has been reported in various articles. The objective of this survey is evaluation of antibacterial effect of Cuminum cyminum L. essential oil on Bacillus cereus in a food model. The essential oil of Cuminum cyminum plant was obtained by steam-distillation and analyzed by GC/MS. Then, effects of different concentrations of this essential oil [0, 50, 150, 300 and 450ppm] on growth of Bacillus cereus were evaluated in commercial barely soup in two storage temperature [10 and 25°C] at 12 intervals [0, 1, 2, 3, 4, 5,6, 9, 12, 15, 18 and 21 days]. The logarithm of Bacillus cereus was significantly decreased by 300 and 450ppm EO concentration incubated at 10°C storage temperature and 450 ppm EO concentration incubated at 25°C storage temperature [p < 0.01]. The results showed, the potential inhibitory effects of the Cuminum cyminum L. essential oil on Bacillus cereus in a food model [commercial barely soup]

[Determination of minimum inhibitory concentration [MIC] of Zataria multiflora boiss. essential oil and Lysozim on E. coli]

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

[Determination of minimum inhibitory concentration [MIC] of zataria multiflora boiss. essential oil and lysozim on L. monocytogenes]

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

[Effect of zataria multiflora boiss. Essential oil on growth and enterotoxin E production of staphylocuccus aureus ATCC 29213]

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

[Effect of zataria multiflora boiss essential oil and nisin on shelf life in light salted fish fillet of silver carp [hypophthalmichthys molitrix]]

Zataria multiflora is medical plants in Traditional Medicine of Iran. It is necessary to study on antimicrobial effects of essential oil on foodborne pathogens. Nisin is bacteriocin, antimicrobial food preservative. It is regarded as natural because it is a polypeptide produced by certain strains of Lactococcus lactis subsp. lactis [hereafter referred to as L. lactis], during fermentation. This study was performed to evaluate the antimicrobial effects of Zataria multiflora Boiss essential oil and Nisin on the shelflife of light salted fish fillet, silver carp. Effects of different concentrations, Zataria multiflora Boiss essential oil [0, 0.045, 0.135, 0.405 and 0.810%] and Nisin [0, 0.25 microg/ml] were studied on shelf life in light salted fish fillets of silver carp at unfavourable refrigeration storage temperature [10 C] by measuring of microbial flora and chemical values such as pH, thiobarbituric acid [TBA] and total volatile basic nitrogen [TVB-N] and perioxide compared with control group. The results showed that higher used concentrations of Zataria multiflora essential oil [0.135, 0.405 and 0.810%] and Nisin [0.25%] had a significant effect on the shelf life of fish fillets [p> 0.05]. The results showed that Z. multiflora essential oil and nisin have antimicrobial effects and are as a food natural preservative in fish fillet. Also, Total volatile basic nitrogen [TVB-N] increased with growth of microbial flora and TVN in the study was best factor for shelf life changes

[Growth inhibition and morphological alterations to Penicellium citrinium in response to Zataria multiflora Boiss. essential oil]

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

[Effect of zataria multiflora boiss. essential oil on the growth of listeria monocytogenes in salted fish]

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

[Evaluation of effects of cuminum cyminum and probiotic on staphylococcus aureus in feta cheese]

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

[Effect of Zataria multiflora Boiss. essential oil on the behavior of Vibrio parahaemolyticus in salted fish]

Thyme [Zataria multiflora Boiss.] is one of the Iranian traditional spices and it has antimicrobial effect on the pathogenic bacteria which are agents for some current food borne intoxications. The aim of this study was to evaluate the antimicrobial activity of Zataria multiflora Boiss. essential oil on V. parahaemolyticus in salted [8% Nacl in tissue] silver carp. Effect of different concentrations of this Essential oil [0.0%, 0.045%, 0.135%, 0.405%, 0.810%] on behavior of V. parahaemolyticus in two temperatures [15, 25 C] 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 V. parahaemolyticus in salted fish compare with control treatment during the storage time [p<0.05]. There was no significant difference between all treatments. The results showed that Zataria multiflora Boiss. Essential oil had inhibitory effect on V. parahaemolyticus, therefore it can be considered as a natural preservative in salted fish

Fate of Listeria monocytogenes during the manufacturing process of Iranian white brined cheese as affected by Zataria Multiflora Boiss. Essential oil

There are many reports about the isolation of Listeria monocytogenes from different kinds of cheese. Natural preservatives such as Zataria multiflora Boiss. Essential oil can inhibit the growth of foodborne pathogens. Evaluation of antibacterial effect of Zataria multiflora Boiss. Essential oil on Listeria monocytogenes in Iranian white brined cheese. The essential oil of this plant were obtained by hydrodistilation and analysed by GC/MS. Effect of different concentrations of this essential oil [0,50, 150 and 300 ppm] on Listeria monocytogenes were evaluated in Iranian white brined cheese. Results showed the significant [p < 0.05] effect of the essential oil at concentrations of 150 and 300 ppmThe results showed, the potential inhibitory effects of the Zataria multiflora Boiss. Essential oil on Listeria monocytogenes in Iranian white brined cheese

[Effect of Zataria multiflora boiss. essential oil and storage temperature on the growth of E.coli O[157]:H[7] in hamburger using hurdle technology]

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]