Changes in the Microbiological Quality of Mangrove Oysters (Crassostrea brasiliana) during Different Storage Conditions

2015 ◽  
Vol 78 (1) ◽  
pp. 164-171 ◽  
Author(s):  
MAIKE TAÍS MAZIERO MONTANHINI ◽  
ROBERTO MONTANHINI NETO

This study aimed to determine the effect of temperature and period of postharvest storage on the microbiological quality and shelf life of raw mangrove oysters, Crassostrea brasiliana. A total of 150 dozen oysters were collected directly from the points of extraction or cultivation in southern Brazil, and in the laboratory, they were stored raw at 5, 10, 15, 20, and 25°C for 1, 4, 8, 11, and 15 days. On each of these days, the oysters were subjected to microbiological analyses of aerobic mesophilic count, total coliforms, enterococci, Escherichia coli, Staphylococcus aureus, and Salmonella. None of the tested samples under any storage condition showed contamination levels above those allowed by Brazilian legislation for E. coli, S. aureus, and Salmonella, and there was no change (P > 0.05) in the counts of these microorganisms due to the temperature and/or period of oyster storage. Counts of enterococci and total coliforms showed a tendency to increase (P < 0.05) among the different temperatures tested. Raw mangrove oysters remain in safe microbiological conditions for consumption up to 8 days after harvesting, regardless of temperature, and their shelf life may be extended to 15 days if they are stored at temperatures not exceeding 15°C.

2000 ◽  
Vol 63 (1) ◽  
pp. 56-62 ◽  
Author(s):  
M. L. BARI ◽  
Y. SABINA ◽  
H. KUSUNOKI ◽  
T. UEMURA

Development of gamma irradiation preservation of ready-to-eat, commercially prepared fish cutlet and improvement of microbiological quality were studied. Studies on the shelf life extension by a combination of irradiation and ascorbic acid treatments of fish cutlets prepared at the laboratory and commercial scale have also been conducted. Cutlets prepared at the laboratory scale according to selected formulation and irradiated at a dose of 5 kGy could extend the shelf life up to 5 weeks at room temperature. In commercially prepared fish cutlets, maximum shelf life extension observed was 14 days for samples treated with 5 kGy of irradiation and stored at ambient temperature on the basis of combined microbiological, chemical, and organoleptic evaluation. The microbiological quality of the commercially prepared fish cutlets revealed the unhygienic conditions of the place where the fish was prepared and the unhygienic storage conditions and temperatures. As a result, the chemical and irradiation treatments were not effective in extending the shelf life of the cutlets under the storage condition used in this study compared with that of the laboratory scale–prepared cutlets.


1991 ◽  
Vol 54 (10) ◽  
pp. 773-777 ◽  
Author(s):  
I. FLISS ◽  
R. E. SIMARD ◽  
A. ETTRIKI

This study was undertaken to evaluate the bacterial contamination level of fresh meat from four different (meat samples) animal species, namely bovine, ovine, poultry, and equine (270 carcasses) collected in various Tunisian slaughterhouses and markets. The level of contamination was assessed using the excised skin technique. All meat surface samples were analyzed for total aerobic microflora, total coliforms, fecal coliforms, and Escherichia coli as an indicator of fecal contamination. Regardless of animal species considered, counts were relatively high for fresh prepared meat. The mean level of contamination for all the meat samples varied from 5.104 to 3.105 CFU/cm2 for total aerobic mesophilic microflora, from 2.102 to 2.103 CFU/cm2 for total coliforms, from 4.101 to 2.102 for fecal coliforms and from 101 to 102 for E. coli. Ovine and poultry carcasses had the highest contamination level. The highest contamination levels were obtained from carcasses prepared in a municipal slaughterhouse and from local markets, where handling and storage conditions were often inappropriate. In this particular case, the total aerobic microflora count reached levels as high as 106 CFU/cm2.


2009 ◽  
Vol 8 (1) ◽  
pp. 11-19 ◽  
Author(s):  
Marta Sofia Valente ◽  
Paulo Pedro ◽  
M. Carmen Alonso ◽  
Juan J. Borrego ◽  
Lídia Dionísio

Monitoring the microbiological quality of water used for recreational activities is very important to human public health. Although the sanitary quality of recreational marine waters could be evaluated by standard methods, they are time-consuming and need confirmation. For these reasons, faster and more sensitive methods, such as the defined substrate-based technology, have been developed. In the present work, we have compared the standard method of membrane filtration using Tergitol-TTC agar for total coliforms and Escherichia coli, and Slanetz and Bartley agar for enterococci, and the IDEXX defined substrate technology for these faecal pollution indicators to determine the microbiological quality of natural recreational waters. ISO 17994:2004 standard was used to compare these methods. The IDEXX for total coliforms and E. coli, Colilert®, showed higher values than those obtained by the standard method. Enterolert® test, for the enumeration of enterococci, showed lower values when compared with the standard method. It may be concluded that more studies to evaluate the precision and accuracy of the rapid tests are required in order to apply them for routine monitoring of marine and freshwater recreational bathing areas. The main advantages of these methods are that they are more specific, feasible and simpler than the standard methodology.


2008 ◽  
Vol 15 (4) ◽  
pp. 414 ◽  
Author(s):  
E. GONZÁLEZ-FANDOS ◽  
A. SIMON JIMENES ◽  
V. TOBAR PARDO

The sensory and microbiological quality of sliced mushrooms (Agaricus bisporus L.) packaged in films of perforated and non-perforated PVC and stored at 3 and 9ºC, was studied. The carbon dioxide and oxygen content inside the packages, colour, weight loss, sensory attributes, mesophiles, Pseudomonas, Enterobacteriaceae, aerobic and anaerobic spore formers were determined. The atmosphere generated with the perforated PVC film was similar to that of air atmosphere at 3 or 9ºC. T.he non-perforated PVC film generated inside the packages CO2 : O2 concentrations of 3.4% : 8.1% at 3ºC and CO2 : O2 concentrations of 4.5% : 0.15% at 9ºC. Browning of mushrooms was lower at 3 than at 9ºC. The quality of sliced mushrooms packaged in perforated PVC and stored at 3ºC was adequate after 9 days. However, at 9ºC, the slice deformation and brown blotches incidence were severe after 9 days. The atmosphere generated with non-perforated PVC inhibited aerobic microorganism growth compared to mushrooms packaged in perforated PVC. At 3ºC, the shelf life of mushrooms packaged in non perforated PVC was around 13 days. However, the extremely low O2 atmospheres generated at 9ºC was accompanied by off-odours and growth of anaerobic spore formers, although the appearance of sliced mushrooms was acceptable.;


2020 ◽  
Vol 76 (09) ◽  
pp. 6444-2020
Author(s):  
JOLANTA KRÓL ◽  
ANETA KARASIŃSKA ◽  
ANETA BRODZIAK ◽  
MAGDALENA STOBIECKA ◽  
JOANNA BARŁOWSKA

The aim of the study was to assess changes in qualitative characteristics of selected dairy products that occur during their shelf life. The research covered 2% pasteurized drinking milk, 18% cream and semi-fat tvarog produced in 3 regional processing plants (A, B and C) and purchased in the local retail network. A total of 186 samples were taken, including 20 samples of each of the above products from plants A and B, and 22 samples of these products from plant C. The following parameters were determined: chemical composition, density, potential acidity (°SH), freezing point, and the number of Enterobacteriaceae in drinking milk; as well as the content of fat, protein and dry matter, potential acidity (°SH), and the number of β-glucuronidasepositive Escherichia coli in cream and tvarogs. The research showed that the dairy products available in the retail network generally met the requirements of Polish standards. Deviations from the standards were found in the fat content of drinking milk and cream compared to that declared by the manufacturer. On both measurement dates, the acidity of the products did not exceed the prescribed limits, which indicates that the quality of the products was maintained during the storage period. The assessment of microbiological quality showed that on both dates the limit of E. coli contamination was exceeded in tvarog samples from dairy C, which indicates an unsatisfactory microbiological quality of the production process in this plant and the need to take corrective actions in the field of production hygiene. Drinking milk and cream, on the other hand, met the legal requirements in terms of process hygiene.


2020 ◽  
Vol 49 (1) ◽  
pp. 32-39 ◽  
Author(s):  
A. Vásquez García ◽  
S.H. Gomes de Sá ◽  
G. de Sousa Silva ◽  
J.E. Mejia Ballesteros ◽  
E. Barbieri ◽  
...  

The objective of this study was to evaluate the microbiological quality of oysters and mussels grown in Cananéia, Brazil, by analysing mesophiles, psychrothophic bacteria, moulds and yeasts, Staphylococcus aureus, and Salmonella spp., and to compare the efficiency of Compact Dry EC method and the conventional method for counting of total coliforms and Escherichia coli. The microbial analysis showed that the mean values of mesophilic counts were 3.14±0.81 log CFU g−1 for oysters and 3.92±0.90 for mussels; the mean values of psychrophilic counts were 2.78±0.75 log CFU g−1 for oysters and 3.22±0.75 log CFU g−1 for mussels; the mean values of mould and yeast counts were 3.70±0.58 log CFU g−1 for oysters and 3.33±0.81 log CFU g−1 for mussels. Salmonella spp. did not present positive results, and the maximal count of Staphylococcus aureus was 1.7 log CFU g−1, therefore, within the limits established in the legislation. The correlation coefficients between the Compact Dry EC method and conventional method were >0.87 for total coliform and E. coli counts for both types of shellfish. The data in this study show that the Compact Dry EC method is an acceptable alternative to conventional methods for enumeration of total coliforms and E. coli in shellfish.


2008 ◽  
Vol 54 (6) ◽  
pp. 495-500 ◽  
Author(s):  
B. Lévesque ◽  
D. Pereg ◽  
E. Watkinson ◽  
J.S. Maguire ◽  
L. Bissonnette ◽  
...  

Bermuda residents collect rainwater from rooftops to fulfil their freshwater needs. The objective of this study was to assess the microbiological quality of drinking water in household tanks throughout Bermuda. The tanks surveyed were selected randomly from the electoral register. Governmental officers visited the selected household (n = 102) to collect water samples and administer a short questionnaire about the tank characteristics, the residents’ habits in terms of water use, and general information on the water collecting system and its maintenance. At the same time, water samples were collected for analysis and total coliforms and Escherichia coli were determined by 2 methods (membrane filtration and culture on chromogenic media, Colilert kit). Results from the 2 methods were highly correlated and showed that approximately 90% of the samples analysed were contaminated with total coliforms in concentrations exceeding 10 CFU/100 mL, and approximately 66% of samples showed contamination with E. coli. Tank cleaning in the year prior to sampling seems to protect against water contamination. If rainwater collection from roofs is the most efficient mean for providing freshwater to Bermudians, it must not be considered a source of high quality drinking water because of the high levels of microbial contamination.


2012 ◽  
Vol 12 (5) ◽  
pp. 556-562 ◽  
Author(s):  
Maria Fernanda Falcone-Dias ◽  
Guilherme L. Emerick ◽  
Adalberto Farache-Filho

The microbiological quality of bottled mineral water of various domestic brands sold in Brazil was investigated, with particular focus on the heterotrophic plate count (HPC). Neither total coliforms nor Escherichia coli were found in any 1.5 L bottle samples. Total coliforms were found in 2.9% of the small bottles, while in 20 L bottles the presence of total coliforms and E. coli was demonstrated in 15.5 and 2.4% of samples, respectively. Pseudomonas aeruginosa was detected in 4.3, 4.5 and 9.5% of small, 1.5 and 20 L bottles, respectively. In 36.4% of the samples of 1.5 L bottles, the HPC was above 500 cfu/mL. This percentage of samples with an HPC above 500 cfu/mL increased to 52.0 and 61.9% in small and 20 L bottles, respectively. Higher contamination by total coliforms, E. coli, P. aeruginosa and HPCs occurred in 20 L bottles. In conclusion, several samples in this study were outside the international quality standard for mineral water and the large number of samples with high HPCs shows that more work must be done on the use of HPC in mineral water and the damaging effects that these microorganisms may cause to humans. The bottled mineral water was confirmed as a particularly important public health problem, due to the poor microbiological quality of the products that are marketed.


2022 ◽  
Vol 17 (12) ◽  
Author(s):  
Ana Carolina Almeida de Oliveira Ferreira ◽  
Erika da Silva Monteiro ◽  
David de Oliveira Sousa ◽  
Calliandra Maria de Souza Silva ◽  
Izabel Cristina Rodrigues Da Silva ◽  
...  

Tilapia (Oreochromis niloticus) is the most cultivated and consumed freshwater fish in Brazil. The present study aimed to evaluate the microbiological quality of ice and fresh tilapia samples commercialized in the Federal District. Tilapia samples were tested for counts of mesophilic and psychrotrophic bacteria, determination of total and thermotolerant coliforms, Staphylococcus aureus counts and presence of Salmonella. Ice samples were analyzed for determination of total coliforms and thermotolerant coliforms and presence of Escherichia coli. Of the 20 samples of fresh tilapia analyzed, ten samples (50%) presented Salmonella (genetically confirmed through the presence of the invA gene) and, therefore, were unfit for consumption. S. aureus was found in 11 samples (55%), and one sample of fillet presented S. aureus counts (3.15 CFU/g) above the limit allowed by Brazilian legislation (3 log CFU/g). S. aureus colonies were confirmed by detection of CoA gene in molecular analysis. Of the 14 ice samples analyzed, 12 samples (85.7%) were unfit for use in fish conservation due to the presence of total coliforms and 9 ice samples (64.3%) were also contaminated with thermotolerant coliforms. E. coli was isolated from 6 ice samples (42.9%) and confirmed in the molecular analysis through the amplification of the MalB gene. In conclusion, the high contamination of tilapia samples with Salmonella and of the ice used for its conservation with coliforms and E. coli indicates the need for better hygienic practices in the tilapia production chain, to increase its quality and microbiological safety.


Author(s):  
Ana Karina Albuja Landi ◽  
Janneth Gallegos ◽  
Paola Vargas Cali ◽  
Paola Arguello Hernández

One of the traditional fresh cheeses in Ecuador is the artisanal leafcheese, a kind of stretched-curd cheese. The artisanal product is wrapped in achira leaves (Canna indica), while the industrial leafcheese is packed at vacuum in high density polyethylene bags. In this study the microbiological quality of both products was compared. The hygienic-sanitary microbial indicators and lactic acid bacteria (LAB) were quantified. The LAB isolated were characterized phenotypically. The samples were obtained from artisanal cheese-making and industrial located in Latacunga city province Cotopaxi. The total aerobic mesophilic count was made based on national regulations (NTE INEN 1529 5); total coliforms, Escherichia coli and Staphylococcus aureus was evaluated using petrifilm methods (AOAC 991.14 – AOAC 2003.07) and to LAB was used PRT-712.02-047. The results show high quantities of total coliforms, E. coli and S. aureus in both products, these data exceed the limits of acceptability established in Ecuadorian regulations, this evidence poor hygienic quality of the processes or incorrect controls of milk as raw material. The lactic acid bacteria count showed statistically significant differences, the industrial cheeses had a reduction of 18,15% of Lactobacillus and 14,27% of Lactococcus compared with artisanal cheeses. A total of 32 strains of lactic acid bacteria were isolated, these showed similar phenotypic characteristics, but these had a different response at the level of pH (4,4;9,4) and NaCl (6,5%). The sensory evaluation will be an important complement in this type of study.


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