List of Articles microbial spoilage

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  1 - Shelf-Life Determination of Common Carp Fillet Dipped in Cinnamon Extract during Storage in Refrigerator
  F. Ghojoghi S. P. Hosseini Shekarabi A. Take
  Introduction: Cinnamon and its extract contain different chemical components that might possess both antimicrobial and antioxidant activities. This study was carried out to evaluate some chemical, microbial and sensory quality changes of common carp fillets treated with More

  Introduction: Cinnamon and its extract contain different chemical components that might possess both antimicrobial and antioxidant activities. This study was carried out to evaluate some chemical, microbial and sensory quality changes of common carp fillets treated with cinnamon extract during refrigerated storage. Materials and Methods: The fish fillets (approximate average weight of 100g) were prepared and divided into three groups. First and second groups were dipped in cinnamon extract with the concentration of 1.5 and 3%, respectively. The third group; the control, was dipped in distilled water. Fish fillets were wrapped in polyethylene package during storage at refrigeration temperature (4±1°C). The chemical tests consisted of peroxide index, thiobarbituric acid, total volatile basic nitrogen and microbial tests including total viable count, psychrotrophic count with sensory evaluation, were performed over the period of 21 days. Results: The results showed that cinnamon extract with 1.5% concentration delayed oxidation and microbial spoilage, while keeping the sensory evaluation score. This concentration was unable to maintain bacterial spoilage, thiobarbituric acid, total volatile basic nitrogen and sensory indices up to the proposed acceptable limit on fourteenth day of the trial. Cinnamon extract at 3% concentration retarded the spoilage indexes in the acceptable limit up to fourteenth day of the cold storage. Conclusion: The cinnamon extract with 3% concentration might be used as a natural antioxidant to retard the spoilage process of fish fillet . However, this concentration was unable to maintain the freshness indexes of the treated fish fillets until the 21-day of the experiment. Manuscript profile
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  2 - Effect of Chitosan on some Microbial and chemical quality of orange juice
  مریم Jeiranikhameneh یحیی Maghsodloo
     One of the biggest obstacles towards orange juice trade is its limited shelf-life. Microbial spoilage is among the reasons for declining the quality of orange juice during storage. The purpose of this study was to determine the impact of chitosan as a natur More

     One of the biggest obstacles towards orange juice trade is its limited shelf-life. Microbial spoilage is among the reasons for declining the quality of orange juice during storage. The purpose of this study was to determine the impact of chitosan as a natural preservative to increase the shelf-life of orange juice. For this, different concentrations of chitosan including 0, 0.4, 0.8, 1, 1.2, 1.6 and 2 g/L were used. During the storage periodmicrobial (total bacterial count) and chemical(Brix and pH) characteristics were assessed.Resultsshowed that higher concentrations of chitosan significantly (p<0.05) inhibit the proliferation microbial population throughout the storage period. Moreover, application of higher concentrations (1.6, 2 g/L) of chitosan increased the pH and Brix in orange juice. That is to say, minimum Brix (12.03) and maximum pH value (4.51) was found in the samples containing 2 g/L of chitosan. Microbial (total bacterial count) counts showed the highest value of 3.45 log cfu/ml in the control sample, and the lowest quantity of 2.43 was determined at concentrations of 1.6 and 2 g/Lof chitosan. It was concluded that chitosan can be used as a natural preservative to prolong the shelf-life of orange juice. Consequently,it could be use as an alternative for thermal treatments which haveharmful effects on the nutritional properties of orange juice. However, comprehensive evaluations dealing with the effect of chitosan on various microbial groups should be performed.  Manuscript profile
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  3 - Study of the effect of incorporation of Lactococcus lactis on the shelf life of rainbow trout fillet in glacial condition
  Asad Abbaspour Anbi Vadood Razavilar Moslem Neyriz Naghadehi Yoseif Ali Asadpour Osalou
  The present study was conducted to evaluate the effect of Lactococcus lactis and its supernatant inclusion in order to increase the shelf-life of rainbow trout fillets stored in the refrigerator. Forty-five pieces of cultured rainbow trout with a total weight of 30 kg w More

  The present study was conducted to evaluate the effect of Lactococcus lactis and its supernatant inclusion in order to increase the shelf-life of rainbow trout fillets stored in the refrigerator. Forty-five pieces of cultured rainbow trout with a total weight of 30 kg were prepared and were immersed in solutions of L. lactis with a dilution of 106 CFUml-1 and its supernatant with percentages of 30 and 60. In order to monitor the corruption procedure of fillet samples, chemical, microbial and sensory factors were analyzed on days 0, 5, 10 and 15. Control fillet samples had the highest and samples of fillets treated with pure bacteria contained the lowest number of microorganisms (P ≤0.05). The mean log of the number of psychrophilic, psychotrophic, mesophilic bacteria, yeast and mold per each gram of fillet was significantly lower than that of control (P ≤0.05). The effect of lactic acid bacteria and supernatant on the reduction of thiobarbituric acid and total volatile nitrogen at the end of storage time was significant (P ≤0.05) but were not significant on pH changes (P >0.05). The use of pure bacteria increased the points given to sensory factors. Samples treated with pure bacteria and supernatants were in good condition in term of taste at the end of the maintenance period while other treatments were unusable. Considering the results, L. lactis and its supernatant is suggested improving the shelf life of rainbow trout fillets. Manuscript profile
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  4 - Study of the effect of Satureja khuzestanica essential oil on the growth of Lactococcus garvieae in rainbow trout fillet at the refrigerator temperature
  Mahsa Ansari Mehdi Soltani Ebrahim Hosseini Abolghasem Kamali
  Abstract This research was done with the aim of study of the antimicrobial effects of Satureja khuzestanica on Lactococcus garvieae and on some spoilage characteristics of rainbow trout fillet in 4°C during 18 days of storage. To do so, 0.06, 0.12, 0.25 a More

  Abstract This research was done with the aim of study of the antimicrobial effects of Satureja khuzestanica on Lactococcus garvieae and on some spoilage characteristics of rainbow trout fillet in 4°C during 18 days of storage. To do so, 0.06, 0.12, 0.25 and 0.5 µg g-1concentration of the essential oil were added to the fillets. According to the results, the highest microbial load was observed in the control group and the lowest was observed in the fillets contained 0.5 µg g-1 of the essential oil (P≤0.05). The results also showed an increase in spoilage characteristics of the fillets at the end of the experiment showing a statistical difference for protein content (P≤0.05). The results of this study revealed that S.khuzestanica results in the reduction of L. garvieaein fish fillets as the concentration of 0.5 µg g-1 was the most effective. Manuscript profile
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  5 - A report on pasteurized orange juice contamination with Bacillus licheniformis
  Hossein Motamedi Amir TajBakhsh
  Abstract Presence of the Fruit juice spoilage bacteria, including Bacillus spp., can be problematic in fruit juice industry. The aim of this study was to isolate and identify the bacteria being able to tolerate orange juice pasteurization conditions. In this study, 16 s More

  Abstract Presence of the Fruit juice spoilage bacteria, including Bacillus spp., can be problematic in fruit juice industry. The aim of this study was to isolate and identify the bacteria being able to tolerate orange juice pasteurization conditions. In this study, 16 samples of orange juice were prepared and investigated in sterile conditions. 0.5 ml of each sample was inoculated in orange serum agar medium and incubated at 43 °C. The isolates were identified using biochemical and antibiogram tests. As a result, From 16 prepared samples, 2 samples were contaminated with bacteria. The bacterium isolated from these samples was able to grow at up to 50 °C on Orange Serum agar. This isolate was then identified as Bacillus licheniformis using the classification system of Linnaeus. Despite of having no pathogenic nature and producing the spores resistant to temperature and acid, Bacillus licheniformis is of great importance according to the viewpoint that it can be mistaken in primary detection by Bacillus of fruit juice which are the spoilage agents and differentiated tests should be done to separate them from Alicyclobacillus spp. for preventing from presenting wrong report. Furthermore, the isolation of these bacteria indicates the inappropriateness of processing conditions to eliminate bacteria from fruit juice that may provide possibilities for growth of fruit juice spoilage bacteria. Manuscript profile
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  6 - A report on pasteurized orange juice contamination to Bacillus licheniformis
  Hossein Motamedi Amir TajBakhsh
  Presence of the Fruit juice spoilage bacteria, including Bacillus spp., can be problematic in fruit juice industry. The aim of this study was to isolate and identify the bacteria being able to tolerate orange juice pasteurization conditions. In this study, 16 samples of More

  Presence of the Fruit juice spoilage bacteria, including Bacillus spp., can be problematic in fruit juice industry. The aim of this study was to isolate and identify the bacteria being able to tolerate orange juice pasteurization conditions. In this study, 16 samples of orange juice were prepared and investigated in sterile conditions. 0.5 ml of each sample was inoculated in orange serum agar medium and incubated at 43 °C. The isolates were identified using biochemical and antibiogram tests. As a result, From 16 prepared samples, 2 samples were contaminated with bacteria. The bacterium isolated from these samples was able to grow at up to 50 °C on Orange Serum agar. This isolate was then identified as Bacillus licheniformis using the classification system of Linnaeus. Despite of having no pathogenic nature and producing the spores resistant to temperature and acid, Bacillus licheniformis is of great importance according to the viewpoint that it can be mistaken in primary detection by Bacilluses of fruit juice which are the spoilage agents and differentiated tests should be done to separate them from Alicyclobacillus spp for preventing from presenting wrong report. Furthermore, the isolation of these bacteria indicates the inappropriateness of processing conditions to eliminate bacteria from fruit juice that may provide possibilities  for growth of fruit juice spoilage bacteria. Manuscript profile
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  7 - The Evaluation of Chemical and Microbial Spoilage Indicators in two Types of Burgers Produced from Fish and Meat During Three Months of Storage at -18°C
  afshin fahim S. T. Shafighi M. Seifzadeh Y. Etemadian M. khabbaz kar amlashi
  The purpose of this study was to evaluate the chemical and microbial spoilage indicators, such as TVN, Peroxide and the total count of mesophilic, Coliforms, Staphylococcus aureus, Escherichia coli and Salmonella bacteria in two types of fish and meat burgers during thr More

  The purpose of this study was to evaluate the chemical and microbial spoilage indicators, such as TVN, Peroxide and the total count of mesophilic, Coliforms, Staphylococcus aureus, Escherichia coli and Salmonella bacteria in two types of fish and meat burgers during three months of storage at -18°C.Silver carp and red meat were immediately transferred to the laboratory of National Fish Processing Research Center (UNIDO), in the presence of ice, after purchase. After weighing, the raw paste was prepared along with other additives, according to the general method of burger production ‎from meat. Chemical and biological tests were based on the method recommended by Iranian National Standards Organization.‎ The results showed that with increasing storage time, TVB-N and peroxide were significantly increased in silver carp burgers, in cold storage,. The mean (±SD) of TVB-N of fish burger changed from 12.6±0.14 mg% at the time of production to 14.4±0.14 mg% and the peroxide changed from zero to 1.33±0.14 meq of oxygen at the end of three months of storage. Total count of mesophilic bacteria, coliform and staphylococcus aurous were lower in fish burgers compared to meat burger products, and for both treatments statistically significant difference was observed for the mean total count of mesophilic bacteria in the first month and for coliform, Staphylococcus aurous bacteria in the second month(p<0.05). Salmonella and E.coli were not observed in any of the treatments and at the end of the storage period they were in accordance with the standards recommended by Iranian National Standards Organization. Therefore, it can be concluded that fish burgers have longer cold storage period compared to burgers produced from red meat. Manuscript profile
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  8 - Propolis as a natural preservative for frozen fish burgers: A kinetic study of lipid oxidation and microbial growth
  محسن مختاریان محسن دلوی Fatemeh Koushki
  The kinetic mechanism of fatty acids or FA degradation and microbial growth rate or MGR in seafood are very important. In this research, the interaction effect of propolis addition (at different concentrations) and storage times on the FA oxidation kinetics and its inhi More

  The kinetic mechanism of fatty acids or FA degradation and microbial growth rate or MGR in seafood are very important. In this research, the interaction effect of propolis addition (at different concentrations) and storage times on the FA oxidation kinetics and its inhibitory role on the suppression of bacterial/fungi growth of stored FFB at -18°C was evaluated. The FA degradation (or microbial growth) rates in FFB during storage period follows the zero-order kinetics. The lowest growth rate (log10 CFU/g) of total viable count (3.66) and fungi (2.43) of FFB was observed after three-months storage in the P-IV, that corresponded to the lowest degradation rate of peroxide value (k0=0.0462 meq O2/kg oil/day) and the highest sensory evaluation scores. Generally, adding 0.4% propolis to FFB and storing them at -18°C for up to 86 days (as the best shelf life) can effectively prevent lipid oxidation and microbial growth and improve sensory quality. Manuscript profile