List of Articles Hamid Mirzaei

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  1 - Effect of different amounts of pH, salt and temperature on survival rate of Lactobacillus casei in milk during storage time
  حمید Mirzaei
        Considering that one of the most important points of probiotic products is the survival rate of live microbes during storage time, so the aim of this study was to determine the effect of different amounts of pH, salt and temperature on survival More

        Considering that one of the most important points of probiotic products is the survival rate of live microbes during storage time, so the aim of this study was to determine the effect of different amounts of pH, salt and temperature on survival rate of Lactobacillus casei in milk during 30 days of storing. For this purpose, at first four erlene Meyers with capacity of 2 litters were selected and 1.5 litter of sterilized milk was added to each of them. Two percent of yoghourt starter was inoculated to each of the first, second and third erlenes and 2% sterilized milk was inoculated to the forth erlene as control group and samples were incubated at 42 ˚C until the pH of first to third samples reached 3.5, 4.5 and 5.5 respectively. Then the erlenes were heated at 90 ˚C for 10 minutes to inactivate the yoghourt starter bacteria and then 500 ml of each sample in first, second, third and forth erlenes was transported to three sterilized caped glass containers and so  four groups consisting of 3 glasses were produced and in each collection 0,  2% and 4% of salt was added to first, second and third samples respectively and then 5 ml of McFarland solution containing 3× 109 cfu/ml of Lactobacillus casei was inoculated to each of the samples. This Procedure was repeated 12 times and obtained samples were stored at about 4˚C in the first six repetitions and at about 25˚C in the second six repetitions. The number of Lactobacillus casei in each of samples was counted soon after production, 4, 8, 12, 16 and 30 days after storing by pour plate method in MRS agar and obtained means were analyzed statistically. According to repeated measures analysis of variance and one way analysis of variance, the mean number of live Lactobacillus casei in samples with pH of 6.5 and 5.5 was significantly more than their numbers in the samples with pH of 4.5 and 3.5 and in the samples stored at 4˚C the number was more than those stored at 25˚C (P<0.01). Whereas salt concentration did not show significant effect on survival rate of Lactobacillus casei in milk. These results showed that milk with pH of 6.5 and 5.5 containing maximum salt of 4%  at 4˚C for about 30 days and at 25˚C for about 15 days is a good environment for storage and transport of  Lactobacillus casei to the consumers. Manuscript profile
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  2 - Survey of Ergosan additive effects on gain weight, perpetuity rate and food conversion index in Rainbow trout
  Sh Notash حمید Mirzaei سعید Sadigh Eteghad
      Evaluation of the effect of Ergosan additive on growth rate, feed conversion index and survival rate of 1gr Rainbow trout hatchlings. The purpose of the present study was to evaluate the effect of consumption of Ergosan additive on production indices More

      Evaluation of the effect of Ergosan additive on growth rate, feed conversion index and survival rate of 1gr Rainbow trout hatchlings. The purpose of the present study was to evaluate the effect of consumption of Ergosan additive on production indices of 1gr Rainbow trouts namely growth rate, feed conversion index and survival rate. Thus the effect of this additive was investigated by selecting five experimental groups (one control and four treatment groups) each consisting of 1500 fish with a weight of 1gram reared in exactly identical conditions. The treatment groups were fed 1, 2, 3 and 4 kg/ton of Ergosan with their diet for 60 days and the data were then analyzed. According to the results, Ergsan had the best effect on the production indices of the third treatment group (3 kg/ton) (p<0.05) and the least production indices were seen in the control group. Consequently, Ergosan additive at the rate of 3kg/ton for 2 months with an interval of 10 days can be included in the diet of Rainbow trouts with the body weight of 1 gram reared at the temperature of 12 ± 0.5 degrees Celsius.   Manuscript profile
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  3 - Study of alterations in the microbial counts of scalder and chiller water in poultry slaughter house
  افشین Javadi حمید Mirzaei Ali Mardani
  The soaking of bird carcasses in the hot water of scalder in order to loosen the feathers inside the follicles and facilitate the subsequent plucking is considered to be one of the critical points of the poultry slaughter house. Chilling and washing of the carcasses are More

  The soaking of bird carcasses in the hot water of scalder in order to loosen the feathers inside the follicles and facilitate the subsequent plucking is considered to be one of the critical points of the poultry slaughter house. Chilling and washing of the carcasses are the other critical points which can cause cross contamination. Thus the purpose of the present study was to determine the alterations in the microbial counts of scalder and chiller water at different times. For this reason, 50 ml samples of scalder and chiller water were collected separately at times zero, 0.5, 1, 1.5, 2 and 2.5 hours following slaughter with 6 replicates for each sample and the total mesophilic and thermophilic bacterial counts of scalder and the total mesophilic and psychrophilic bacterial counts of chiller were investigated. The results indicated that the mesophilic counts of scalder had decreased significantly over time but the thermophilic bacterial levels had increased significantly (p<0.01). Also the mesophilic and psychrophilic bacterial counts of chiller had decreased significantly (p<0.01). Manuscript profile
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  4 - Study on the effect of dextrose, valine, glycine, thiamine and different temperatures on growth rate of Bifidobacterium bifidum in milk
  حمید Mirzaii افشین Javadi یونس Barzegar
       The first step in utilizing appropriate microorganisms to produce probiotic milk products is to recognize their growth conditions in milk and the factors influencing them. In this research, the effect of dextrose, valine, glycine, thiamine and differ More

       The first step in utilizing appropriate microorganisms to produce probiotic milk products is to recognize their growth conditions in milk and the factors influencing them. In this research, the effect of dextrose, valine, glycine, thiamine and different temperatures on growth rate of Bifidobacterium bifidum in milk has been studied and for this purpose, fermented milk by B. bifidum has been used as stock culture in order to inoculate the milk samples. First 28, 35, 42, 49 and then 35, 38, 41 and 44°C incubators were used to choose the suitable incubation temperature for growth of the microorganisms and the acidity of milk samples were measured as a growth index of the microorganisms prior to and during incubation. Concentrations of 0 (control), 5, 10 and 15 ppm of thiamine; 0(control), 0.4, 0.6, 0.8 and 1% of dextrose; 0(control), 30, 60, 90 and 120 ppm of glycine and valine were used to evaluate their effects on the growth rate of B. bifidum and acidity of milk samples were measured before incubation and after 2, 4, 6 and 8 hours of incubation at 42°C. The rate of increase of acidity at 44°C and 41°C was significantly higher than the other temperatures (p<0.05). The addition of different concentrations of dextrose, valine and glycine had no significant effect on the rate of increase of acidity of the milk samples. The addition of thiamine also had no significant effect on the acidity although it reinforced the ability of B. bifidum in the production of proteolytic enzymes and gas. Manuscript profile
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  5 - Effect of warm-smoking on total microbial count of meat products
  افشین Javadi حمید Mirzaii پیام Pashak
       The frankfurters are amongst the most famous and popular sausages in the world and beef and poultry meat are used in Iran for their preparation. The techniques of warm smoking at 42°c for two hours and then hot smoking together with steam cooking More

       The frankfurters are amongst the most famous and popular sausages in the world and beef and poultry meat are used in Iran for their preparation. The techniques of warm smoking at 42°c for two hours and then hot smoking together with steam cooking at 8°c for one hour are utilized in proportion of this product. In spite of its carcinogenic properties, smoke is used to create color, flavor and odor and to improve the preservative qualities of sausages. In this study, 14 sausage samples were taken from each of the stages of frankfurter production line including pre-smoking, post- warm smoking and post-hot smoking, their total microbial counts (aerobic mesophiles) determined and the means of the three stages compared using the ANOVA statistical test. The results indicated that the total microbial count increased significantly (P<0.05) during warm smoking compared to the pre-smoking stage and a subsequent significant decrease (P<0.05) was observed during the hot smoking stage but there was no significant difference after the hot smoking stage in comparison to the pre smoking stage. Although there are antimicrobial compounds in smoke, it seems that these compounds are not absorbed by the product during warm smoking at 42°c which is the optimum temperature for microbial growth and therefore the total microbial count increases during this stage but hot smoking at 80°c decreases the total microbial count.   Manuscript profile
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  6 - Study on the effects of consumption of milk containing Lactobacillus acidophilus on serum lipid trends and weight gain of rats fed high lipid diet
  حمید Mirzaei مهران Mesgari abbasi عیسى Tajmohammadi
        Despite the significant progresses made in the reduction of mortality due to cardiovascular diseases, they are still the primary cause of death in many countries and hyperlipidemia is an important causal agent of cardiovascular diseases. Probio More

        Despite the significant progresses made in the reduction of mortality due to cardiovascular diseases, they are still the primary cause of death in many countries and hyperlipidemia is an important causal agent of cardiovascular diseases. Probiotics are food supplements containing live microbes which balance the flora of the digestive system and produce positive effects in the host body. L.acidophilus is a beneficial bacterium used in the production of probiotic products .The aim of this study is to evaluate the effects of consumption of milk containing L.acidophilus on serum lipid trends of rats fed high lipid diet. This is an experimental study in which 30 male albino Wistar rats with a body weight of 200±15 gr. were randomly allocated to two groups of treatment and control each containing 15 rats which were adapted to a high lipid diet (11.74%) and water containing 25% milk within a week. Rats in both groups received high lipid diet and water containing 25% milk for 60 days with the exception that rats in the treatment group received water containing L. acidophilus at a level of 109 CFU/rat/day throughout the experiment. Independent t-test revealed that at a level of α= 0.05, mean levels of total cholesterol and LDL-C of rats in the treatment group was significantly lower than the control group (p<0.05), and HDL-C of rats in the treatment group was significantly higher than the control group (p<0.05), but the mean levels of triglyceride and VLDL-C was not significantly different. Also increase in body weight was significantly higher in the treatment group compared with the control group (p<0.01). On the whole, long term daily consumption of milk containing L. acidophilus improves serum lipid trends by lowering total cholesterol level and LDL-C and increasing HDL-C and also increases the rate of body growth.   Manuscript profile
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  7 - Electrophoretic study of whey proteins in Holstein cows with clinical and subclinical mastitis by Agarose gel procedure
  افشین Davasaz Tabrizi R.A Batavani سیامک Asri Rezaie ملاحت Ahmadi حمید Mirzaie
         Mastitis is one the most important economic diseases in dairy cattle industry, which causes reduction in milk production, treatment expenses, reduction in herd genetic progress and fall in quality of milk. The aim of this study was to ex More

         Mastitis is one the most important economic diseases in dairy cattle industry, which causes reduction in milk production, treatment expenses, reduction in herd genetic progress and fall in quality of milk. The aim of this study was to examine the milk proteins of Holstein dairy cows with different grades of clinical and subclinical mastitis. During the sampling period, none of the cows were in late pregnancy or at early lactation and also had no parasitemia and any other inflammatory diseases.  Clinical and laboratory examinations which were carried out completely revealed the cows were all healthy. They were fed on corn silage, concentrate and alfalfa. In this study, the cows were divided into five groups, each group with 25 cases. For this purpose, milk samples were collected from 125 dairy cattle of two large dairy farms in Tabriz. All the cows were in the lactation period and they were milked three times a day. The groups consist of the control group with negative California mastitis test and negative culture, 2+ subclinical groups, 3+ subclinical group, sub acute clinical group and acute clinical group. The results of the whey electrophoresis using Agarose gel procedure indicated significant difference in albumin levels in all groups except the 2+ subclinical group compared with the control group (p<0.01). There was no difference in beta lactoglobulin and alpha lactalbumin levels in comparison with the control group. The combined levels of alpha and beta globulins in the two groups suffering from clinical mastitis was significantly different from the control groups (p<0.01) but this discrepancy was not significant in the two subclinical groups. In addition, the level of gamma globulins in all mastitis groups was significantly different from the control groups (p<0.01). In conclusion of this study indicated that with the rise in the intensity of infection and inflammation of the mammary tissue, whey proteins especially alpha and beta globulins increase clearly and significantly. Manuscript profile
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  8 - Effect of probiotics in poultry diet on microbial hazards of poultry meat
  افشین Javadi حمید Mirzaii عیسی Ebrahimi
          Probiotics are products from microbial cells that have useful influence on health and tranquility of humans. According to numerous studies, many valuable properties such as anti-mutagenic, anti-carcinogenic, boosting body immun More

          Probiotics are products from microbial cells that have useful influence on health and tranquility of humans. According to numerous studies, many valuable properties such as anti-mutagenic, anti-carcinogenic, boosting body immunity and resistance against enteric pathogens have been attributed to probiotics. Therefore the aim of this study is to specify the effect of probiotics use in the diet of broilers on microbial hazards of poultry meat. For this purpose, two groups of treatment and control each containing 40 broiler chicks were chosen and edible probiotic were given to the treatment group throughout the whole 55 days of the rearing period under the same conditions and following slaughter 100 grams of skin and breast meat samples were collected from each carcass and transferred to food hygiene laboratory of the veterinary faculty under sterile conditions. Total microbial count,    Staphylococcus aureous, fecal Streptococci, Clostridium perferingens, Coliforms counts and detection of Salmonella and E.coli were performedon the samples according to standard approaches of Iran. The results were analyzed using independent t-Test and Chi-square test. Comparison of the means of total microbial count, coliform, enteric streptococci and meat staphylococcus counts in the control and treatment group using independent t-Test showed a significant reduction (p<0.005). Also, detection of E.coli in the treatment group showed a significant reduction in comparison with the control group (p<0.05) although, Salmonella and Clostridium reductions were not statistically significant. It seems that oral consumption of probiotics is effective in the reduction of enteric pathogenic bacteria of poultry meat. Therefore, if the frequency and level of microbial contamination of food including poultry meat with these micro-organisms is reduced on effective step is undertaken towards reduction of food born diseases and improvement of hygienic quality and shelf life of poultry meat.    Manuscript profile
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  9 - Study on the effect of Lactobacillus casei o1 fermented milk consumption on lipid pattern of rats nourished with cholesterol enriched diet
  حمید Mirzaei بهرام Amouoghli Tabrizi مهدی Rafiei
  The aim of this study was to evaluate the effects ofconsumption of different amounts of fermented milk by L.casei on serum lipid trends including total cholesterol, LDL-C, HLD-C, VLDL-C and triglyceride in the serum of rats fed 1 and 2% cholesterol enriched diet. For th More

  The aim of this study was to evaluate the effects ofconsumption of different amounts of fermented milk by L.casei on serum lipid trends including total cholesterol, LDL-C, HLD-C, VLDL-C and triglyceride in the serum of rats fed 1 and 2% cholesterol enriched diet. For this purpose 49 male albino wistar rats with a body weight of 200±15 gr were randomly allocated to seven groups each containing 7 rats and adapted to new conditions during a week. Rats in the first group (control group) received commercial diet and water for 30 days, the second to fourth groups received diet enriched with 1% cholesterol and rats in the fifth to seventh groups received diet enriched with 2% cholesterol. Each rat in the fourth and seventh groups (double dose receiving treatment groups) consumed fermented milk containing 4×108 CFU bacteria per day, rats in the third and sixth groups (single dose receiving treatment groups) consumed fermented milk containing 2×108 CFU bacteria per day and in the second and fifth groups (sham group) consumed sterilized milk instead of fermented milk. According to the statistical tests, one way analysis of variance and Tukey at a level of α= 0.05, mean levels of total cholesterol and LDL-C of rats in the  double dose receiving treatment groups and single dose receiving treatment groups were significantly lower and mean level of HDL-C was significantly higher than sham group (p<0.05). In the rats fed  1% enriched cholesterol, mean levels of VLDL-C and triglyceride of rats in the  double dose receiving treatment groups were significantly lower than sham group (p<0.05). Long term daily consumption of milk fermented by L.casei improves serum lipid trends by lowering total cholesterol and LDL-C level and by increasing HDL-C level. The effectiveness of this probiotic on lipid trends is dose dependent. Manuscript profile
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  10 - Effect of some probiotics on Salmonella paratyphi during associated growth in milk
  حمید Mirzaei افشین Javadi یوسف Angouri
        The aim of this study is to determine the effects of Lactobacillus acidophilus, Lactobacillus casei, Bifidobacterium angulatom and Bifidobacterium bifidum on salmonella paratyphi in associated condition in milk. At first a quantity of 1.5 &time More

        The aim of this study is to determine the effects of Lactobacillus acidophilus, Lactobacillus casei, Bifidobacterium angulatom and Bifidobacterium bifidum on salmonella paratyphi in associated condition in milk. At first a quantity of 1.5 × 108 cfu/ml activated S. paratyphi was added to 500 ml of sterile milk and after homogenization distributed equally in five erlene meyers. The first erlene meyer was considered as individual culture and in to the second, third, fourth and fifth erlene meyer a quantity of 1.5×108 cfu/ml of the above probiotic was inoculated respectively and after 24-48 hours of incubation at 37 oC, pH was measured by pH meter and S. paratyphi count was determined by pour plate method in SSA medium. This procedure was repeated 10 times and the mean of pH and number of S. paratyphi in one ml of individual culture and with probiotic cultures was compared using statistical analysis.  According to statistical tests of ANOVA and Tukey at α=0.05, in 24 and 48 hour incubation of associated growth of L. acidophilus, L. casei and B. bifidum had significant inhibitory effect on S. paratyphi growth (p<0.01). However, in similar condition associated growth of L. angulatum did not show significant inhibitory effect on S. paratyphi growth. Meanwhile, in 24 and 48 hour incubation of associated growth of L. acidophilus, L. casei and B. bifidum reduced the mean of pH of milk samples compared to control sample significantly (p<0.01). These results show the consumption of probiotic products containing B. angulatom, B. bifidum, L. acidophilus and L. casei could have beneficial effects in prevention of Salmonella paratyphi infection. Although further research especially at in vivo condition in this aspect should be carried out. Manuscript profile
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  11 - Study of effect several levels of multi-enzyme on performance parameters and survival rate in rainbow trout (Oncorhyncus mykiss
  S.J Mortazavi Tabrizi مسعود Nejati SH Notash حمید Mirzaii
  This study was designed to investigate the influence of supplementing multi-enzyme in feed on growth and survival rate of rainbow trout fish. The multi-enzyme were incorporated into a commercial pellet ration to constitute three experimental diets containing 500, 1000, More

  This study was designed to investigate the influence of supplementing multi-enzyme in feed on growth and survival rate of rainbow trout fish. The multi-enzyme were incorporated into a commercial pellet ration to constitute three experimental diets containing 500, 1000, 1500 gram kemin phytase multi-enzyme per one ton feed intake, while a fourth diet without the multi-enzyme supplement served as the control diet. The diets were offered to rainbow trout (150 g average weight) in quadruplicate pools (each treatment) for 40 days. Fish were sampled at 10, 20, 30 and 40 days after commencement of the feeding trial to determine feed conversion ratio (FCR), weight and length rate and survival rate. Results of our study indicated that effect of different supplementing multi-enzyme levels on feed conversion ratio (FCR), weight and length rate and survival rate, there was not any meaning relation in dose rates (p>0.05). According to affect of type and concentrates of enzyme on animal response, we can recommend that type or concentrates of consummated kemin- phytase multi-enzyme is not suitable for rainbow trout. Manuscript profile
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  12 - Experimental study on effect of roasting, boiling and microwave cooking methods on enrofloxacin antibiotic residues in edible poultry tissues
  افشین Javadi حمید Mirzaei S.A Khatibi علی Manaf Hosseyni
  The purpose of this study was to determine the effects of different cooking processes such as boiling, roasting and microwaving on enrofloxacin residues in muscle, liver and gizzard tissues of broiler chickens. Each of chicks was fed by routine diet and water with %0.05 More

  The purpose of this study was to determine the effects of different cooking processes such as boiling, roasting and microwaving on enrofloxacin residues in muscle, liver and gizzard tissues of broiler chickens. Each of chicks was fed by routine diet and water with %0.05 of enrofloxacine for consecutive 5 days .Then; three locations including breast muscle, liver and gizzard were sampled aseptically from each carcass. Enrofloxacin residue was analyzed using microbial method by plates seeded with Escherichia coli. After doing different phases of the test on raw samples, the positive raw samples cooked by various cooking procedures and we surveyed cooked samples with similar method again for present of residue. The results were show reduction in concentration of enrofloxacin residue after different cooking processes. The most reduction of the residue in cooked meat and gizzard samples related to boiling process and roasting process for cooked liver samples and the highest detectable amount of residue belonged to microwaving process in all cooked samples. Regarding to the results of this study, we can conclude that cooking processes can’t annihilate total amounts of these drug and it can only decrease their amounts and the most of residue in boiling process excreted from tissue to cooking fluid. Manuscript profile