Kowsar Mokarizadeh; Abdulghaffar Ownagh; Hossein Tajik
Volume 14, Issue 5 , May 2023, , Pages 289-293
Abstract
There are few studies on Coxiella burnetii (Cb) as a causative agent of Q fever in dairy products in Iran. The prevalence of Cb was studied by polymerase chain reaction (PCR) method in Kope (pot) cheese and cattle milk collected from West Azerbaijan province, Iran. A total number of 240 Kope cheese and ...
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There are few studies on Coxiella burnetii (Cb) as a causative agent of Q fever in dairy products in Iran. The prevalence of Cb was studied by polymerase chain reaction (PCR) method in Kope (pot) cheese and cattle milk collected from West Azerbaijan province, Iran. A total number of 240 Kope cheese and 560 milk samples were collected during the year 2020. All samples were subjected to PCR based on transposable gene IS1111. The results showed that 12.50% (95.00% confidence interval (CI): 9.00% - 16.10%) of Kope cheese and 13% (95.00% CI: 10.00% - 17.30%) of milk samples were positive for Cb. There was a significant difference in cheese and milk contaminations with Cb among the defined age groups as well as regional and seasonal variations. It was concluded that Kope cheese and cattle milk are important sources of Cb and should be considered as important risk factors in the epidemiology of Q fever disease in public health.
Abdulghaffar Ownagh; Navid Etemadi; Peyman Khademi; Hossein Tajik
Volume 14, Issue 1 , January 2023, , Pages 21-28
Abstract
Salmonellosis is one of the most important bacterial diseases in human and animals. Rapid diagnosis and sub sequence accurate treatment of Salmonella carriers help reduce the salmonellosis in human and livestock animals. In this study, 420 fecal samples were taken during year 2019 from buffalo in the ...
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Salmonellosis is one of the most important bacterial diseases in human and animals. Rapid diagnosis and sub sequence accurate treatment of Salmonella carriers help reduce the salmonellosis in human and livestock animals. In this study, 420 fecal samples were taken during year 2019 from buffalo in the Urmia, Khoy and Piranshahr regions in west Azerbaijan province, Iran. Samplings were carried out in different seasons. Presence of Salmonella invasion genes (FimA, Stn and InvA) were evaluated by polymerase chain reaction. The bacterial culture and biochemical tests were performed on feces samples for isolation of bacterium Salmonella; however, all samples were negative in culture method. PCR findings showed that, 50 (11.90%) fecal samples were positive to the genes. The analysis of results showed that frequency of salmonellosis outbreak in different parts of west Azerbaijan province followed a similar pattern and the incidence of salmonellosis according to forecast in the warm seasons (spring and summer) was more than in cold seasons (autumn and winter). The prevalence of Salmonella in buffalo’s feces based on warm and cold seasons were 32 (64.00%) and 18 (36.00%), respectively. The results showed significant difference between cold and warm season in the prevalence of salmonellosis. Therefore, the application of molecular technics is essential for the prevention and treatment of salmonellosis. The results also showed that specificity of PCR method was better than culture method for detection of Salmonella in feces sample.
Food Hygiene
Mehran Moradi; Hossein Tajik; Karim Mardani; Parya Ezati
Volume 10, Issue 3 , September 2019, , Pages 193-198
Abstract
In the present study, the effect of different concentrations of cell-free supernatant (CFS; 10.00 and 35.00 mg g-1) of Lactobacillus salivarius (Ls-BU2) on chemical, microbial and sensorial specifications of ground beef stored under the refrigerated condition was investigated. The antibacterial activity ...
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In the present study, the effect of different concentrations of cell-free supernatant (CFS; 10.00 and 35.00 mg g-1) of Lactobacillus salivarius (Ls-BU2) on chemical, microbial and sensorial specifications of ground beef stored under the refrigerated condition was investigated. The antibacterial activity of CFS on Escherichia coli was also assessed. According to agar-disk diffusion method, CFS of Ls-BU2 revealed a promising antibacterial activity against E. coli in culture media compared to CFS of a well-known probiotic (L. acidophilus LA-5). In meat, CFS of Ls-BU2 showed a minimal effective concentration (MEC) of 35.00 mg g-1 on E. coli, while CFS of L. acidophilus represented a MEC of > 45.00 mg g-1. The CFS of Ls-BU2 at 35.00 mg g-1 concentration retained psychrophilic counts of meat at a lower value than maximum accepted level (7 log10 CFU g-1). In a similar trend, CFS of Ls-BU2 at 35.00 mg g-1 concentration was also displayed high sensorial scores compared to other CFS-treated samples. In conclusion, we demonstrated that CFS of Ls-BU2 and to some extent CFS of L. acidophilus could act as a safe food additive for the control of bacterial pathogens and to extend the shelf life of ground beef.
Food Hygiene
Fatemeh Esmaeli; Hossein Tajik; Tooraj Mehdizadeh; Mahsa Maiely
Volume 10, Issue 2 , June 2019, , Pages 109-117
Abstract
In the present study, the antioxidant and antimicrobial effects of essential oil (EO) and extract of Pimpinella affinis on the shelf life of rainbow trout during storage at refrigerator temperature based on three indicators of microbial, chemical and sensory quality parameters were evaluated. For this ...
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In the present study, the antioxidant and antimicrobial effects of essential oil (EO) and extract of Pimpinella affinis on the shelf life of rainbow trout during storage at refrigerator temperature based on three indicators of microbial, chemical and sensory quality parameters were evaluated. For this purpose, fish samples were stored in zein coatings containing 1.00% EO and 2.00% extract and in combination treatment containing 1.00% of each of them in refrigerator for 12 days. All of treatments were analyzed for microbiological count (Enterobacteriaceae, psychrophilic bacteria, mesophilic bacteria and pseudomonas bacteria) and chemical including pH, thiobarbituric acid reactive substances (TBARS), total volatile base nitrogen, peroxide value (POV) and free fatty acids (FFAs) and sensory (odor, color and texture) characteristics. Results showed that the highest levels of three factors including TBARS, POV and FFAs were related to the control sample and the least amount of these parameters was observed in EO and extract combination treatments. This effect of combined treatment was also observed in the reduction of total volatile basic nitrogen and pH parameters. Total bacterial counts during storage in fish treated with the extract and EO were remained below the acceptable level and microbial spoilage was significantly decreased compared to control. According to the sensory evaluation, treatments containing EO and extract showed improvement in this index compared to control treatment during storage. Based on the results of this study, it can be concluded that the EO and extract of P. affinis as active ingredients in zein coating successfully improve the quality and shelf life of the fish in the refrigerator.
Food Hygiene
Ali Mojaddar Langroodi; Hossein Tajik; Tooraj Mehdizadeh
Volume 9, Issue 2 , June 2018, , Pages 153-161
Abstract
Beef is susceptible to rapid spoilage due to its high amount of protein (18.00%) and moisture (72.00%). Food industries have recently found methods to extend beef shelf-life. The influence of beef dipping in hydro-alcoholic extract of sumac (SE) and chitosan (CH) coating incorporated with Zataria multiflora ...
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Beef is susceptible to rapid spoilage due to its high amount of protein (18.00%) and moisture (72.00%). Food industries have recently found methods to extend beef shelf-life. The influence of beef dipping in hydro-alcoholic extract of sumac (SE) and chitosan (CH) coating incorporated with Zataria multiflora essential oil (ZEO) on microbial, chemical and sensory quality of beef was evaluated during refrigerated storage. Total viable counts (TVC), lactic acid bacteria, Pseudomonas spp., Enterobacteriaceae and yeasts-molds, total volatile nitrogen (TVN), thiobarbituric acid reactive substance values (TBARS) and peroxide value (PV) were founded to be significantly lower in all treatment groups compare to control groups during storage time.The highest level of antimicrobial effects induced by chitosan, SE 4.00% and ZEO. We found that in TVC (3.69 log CFU g-1 reduction compared with control group (sterile distilled water), Enterobacteriaceae (3.61 log CFU g-1 reduction) and lactic acid bacteria (2.67 log CFU g-1 reduction), respectively. Sumac gave a pleasant effect on sensory attributes and chitosan coating enriched with ZEO significantly improved sensory scores except for flavor factor. The results revealed the bio preservative properties of chitosan, hydro-alcoholic extract of sumac and Z. multiflora Boiss essential oil during refrigeration in normal packaging of beef.
Hossein Tajik; Aligholi Ramin; Shahram Nozad; Babak Jelodari; Zohreh Eftekhari; Sina Ramin
Volume 3, Issue 4 , December 2012, , Pages 275-279
Abstract
Lipids in liver wet and dry matter, liver moist and dry matter and their relationships were investigated based on species, sex and age in cows, buffaloes, sheep and goats. Mean percentage of lipids in liver wet and dry matter and liver dry matter in cows were 3.60%, 1.10%, 29.70%, and for buffaloes were ...
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Lipids in liver wet and dry matter, liver moist and dry matter and their relationships were investigated based on species, sex and age in cows, buffaloes, sheep and goats. Mean percentage of lipids in liver wet and dry matter and liver dry matter in cows were 3.60%, 1.10%, 29.70%, and for buffaloes were 5.30%, 1.55%, 29.20%, sheep 3.00%, 0.83%, 27.90%, and goats 2.910%, 1.55% and 28.40%, respectively. The highest and lowest percentage of lipids in liver wet and dry matter was observed in buffaloes and sheep, and for the liver dry matter was recorded in cows and sheep, respectively. Analyses showed significant differences in liver parameters among ruminants (p < 0.01). Gender, except for goats, did not affect the animals' liver parameters. In overall 15.00% of buffaloes and 3.50% of cows showed over 10.00% lipids in liver, while none of small ruminants appeared to have over 6.00% lipids in liver. There was no correlation between liver lipid and liver dry matter. In conclusion mean percentage of lipid in liver dry matter in small ruminants was less than large ruminants. Liver dry matter was high in cows and low in sheep. Mean differences in liver parameters was significant, while the age and sex of the animals were not. Liver lipidosis in buffaloes seems greater than in cows, and in small ruminants it was negligible. No correlation was expected between liver parameters. Finally, on the basis of liver dry matter, the liver in ruminants ranked from cows to buffaloes, goats and sheep.
Tooraj Mehdizadeh; Hossein Tajik; Seyed Mehdi Razavi Rohani; Abdol Rassol Oromiehie
Volume 3, Issue 3 , September 2012, , Pages 167-173
Abstract
Thyme Essential oils (EO) with antimicrobial and antioxidant properties are widely used in pharmaceutical, cosmetic, and perfume industry. It is also used for flavoring and preservation of several foods. Nowadays, packaging research is receiving a considerable attention due to the development of eco-friendly ...
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Thyme Essential oils (EO) with antimicrobial and antioxidant properties are widely used in pharmaceutical, cosmetic, and perfume industry. It is also used for flavoring and preservation of several foods. Nowadays, packaging research is receiving a considerable attention due to the development of eco-friendly materials made from natural polymers such as starch and chitosan. In this study Thymus kotschyanus EO concentrations ranging from 0 to 2.0%, incorporated in starch-chitosan composite (S-CH) film were used. Antimicrobial and antioxidant properties significantly increased with the incorporation of EO (p < 0.05). Incorporating EO, increased total color differences (DE), yellowness index (YI) and whiteness index (WI) which were significantly higher than control and its transparency was reduced. Our results pointed out that the incorporation of Thymus kotschyanus EO as a natural antibacterial agent has potential for using the developed film as an active packaging.
Razzaqh Mahmoudi; Hossein Tajik; Ali Ehsani; Payman Zare
Volume 3, Issue 3 , September 2012, , Pages 193-197
Abstract
Increasing incidence of food-borne disease along with its social and economic consequences have led to conducting extensive research in order to produce safer food and develop new antimicrobial agents; among them, extensive use of probiotics and bacteriocins as biological additives is of significant ...
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Increasing incidence of food-borne disease along with its social and economic consequences have led to conducting extensive research in order to produce safer food and develop new antimicrobial agents; among them, extensive use of probiotics and bacteriocins as biological additives is of significant importance. The aim of the present study was to evaluate the interactions (growth behavior and survival) of Listeria monocytogenes and Lactobacillus acidophilus in various stages of production, ripening and storage of Iranian white cheese. Changes in pH values at different stages of cheese ripening, along with changes in organoleptic properties of cheese were also assessed. Compared to other treatments, in the treatment of cheese with probiotic agent without starter, the most significant decrease in Listeria monocytogenes count at the end of ripening stage was observed (3.16 Log per gram cheese compared with the control group) (p < 0.05). Survival of probiotic bacteria in control samples of cheese were significantly higher when compared to cheese sample contaminated with Listeria (p < 0.05). White probiotic cheese with starter had the highest of sensory acceptability (p < 0.05). Listeria Monocytogenes count decreased during ripening period of probiotic white cheese but the bacteria survived in probiotic white cheese. Lactobacillus acidophilus count decreased during ripening period of white cheese but it did not lower to less than 106 CFU per g at the end of ripening and storage periods.