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Anh Ngoc Tong Thi - One of the best experts on this subject based on the ideXlab platform.
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microbiota of frozen vietnamese catfish Pangasius hypophthalmus marketed in belgium
International Journal of Food Contamination, 2016Co-Authors: Anh Ngoc Tong Thi, Simbarashe Samapundo, Frank Devlieghere, Marc HeyndrickxAbstract:Vietnamese catfish (Pangasius hypophthalmus) is highly appreciated in many European countries, the U.S., Canada, Japan etc. This paper presents an overview of the microbiota of frozen Vietnamese catfish products marketed in Belgium. Samples of Pangasius steaks, portions and fillets from six brands were collected from supermarkets located in Ghent, Belgium. The total psychrotrophic and mesophilic aerobic counts of the samples evaluated from each brand did not differ significantly (p > 0.05) and ranged from 3.8-5.2 log CFU/g and 3.8-4.8 log CFU/g, respectively. Lactic acid bacteria counts varied from 2.2 to 4.1 log CFU/g while the counts of presumptive Enterobacteriaceae ranged from 1.6 to 3.8 log CFU/g. A total of 132 isolates were collected from the plates used to enumerate the microbial parameters mentioned above. Fourteen different genera and 18 different species were identified by means of 16S rRNA gene sequencing. The most prevalent genera of Lactococcus (31.2 %), Staphylococcus (11.7 %), Serratia (10.4 %), Acinetobacter (9.1 %), Enterococcus (7.8 %) and Pseudomonas spp. (6.5 %) were identified by means of 16S rRNA gene sequencing. The results obtained provide an overview of the dominant microbiota on frozen Pangasius which is useful for the development of appropriate preservation techniques for thawed Pangasius products.
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evaluation of the safety and quality of wash water during the batch washing of Pangasius fish Pangasius hypophthalmus in chlorinated and non chlorinated water
Lwt - Food Science and Technology, 2016Co-Authors: Anh Ngoc Tong Thi, Imca Sampers, Sam Van Haute, Simbarashe Samapundo, Bruno De Meulenaer, Marc Heyndrickx, Frank DevlieghereAbstract:Abstract This study investigated the continuous dosing of chlorine to the wash water by means of a pump to maintain antimicrobial levels of free chlorine in the wash water during the washing of 12 batches of Pangasius fillets. In comparison to the control (no chlorination), total psychrotrophic bacteria were reduced by between 2 and 4 log CFU/100 ml. After the final batch was washed, total chlorine and organic matter in the water sampled had accumulated to 482.9 ± 17.0 ppm and 4447.5 ± 187.4 mg O 2 /L, respectively. However, only 8.9 ± 1.3 μg/L of trihalomethanes was formed in the chlorinated wash water whereas no trihalomethanes were detected in the washed Pangasius fillets after rinsing. It was concluded that the Pangasius fillets washed in chlorinated water continuously dosed with chlorine were safe for human consumption even after a throughput of 12 batches. However, the organoleptic properties of Pangasius fillets washed in the final batch differed significantly from those washed earlier batches.
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decontamination of Pangasius fish Pangasius hypophthalmus with chlorine or peracetic acid in the laboratory and in a vietnamese processing company
International Journal of Food Microbiology, 2015Co-Authors: Anh Ngoc Tong Thi, Imca Sampers, Sam Van Haute, Simbarashe Samapundo, Marc Heyndrickx, Binh Ly Nguyen, Frank DevlieghereAbstract:Abstract This study evaluated the decontamination of Pangasius fillets in chlorine or peracetic acid treated wash water. First, the decontamination efficacy of the washing step with chlorinated water applied by a Vietnamese processing company during trimming of Pangasius fillets was evaluated and used as the basis for the experiments performed on a laboratory scale. As chlorine was only added at the beginning of the batch and used continuously without renewal for 239 min; a rapid increase of the bacterial counts and a fast decrease of chlorine in the wash water were found. This could be explained by the rapid accumulation of organic matter (ca. 400 mg O 2 /L of COD after only 24 min). Secondly, for the experiments performed on a laboratory scale, a single batch approach (one batch of wash water for treating a fillet) was used. Chlorine and PAA were evaluated at 10, 20, 50 and 150 ppm at contact times of 10, 20 and 240 s. Washing with chlorine and PAA wash water resulted in a reduction of Escherichia coli on Pangasius fish which ranged from 0–1.0 and 0.4–1.4 log CFU/g, respectively while less to no reduction of total psychrotrophic counts, lactic acid bacteria and coliforms on Pangasius fish was observed. However, in comparison to PAA, chlorine was lost rapidly. As an example, 53–83% of chlorine and 15–17% of PAA were lost after washing for 40 s (COD = 238.2 ± 66.3 mg O 2 /L). Peracetic acid can therefore be an alternative sanitizer. However, its higher cost will have to be taken into consideration. Where (cheaper) chlorine is used, the processors have to pay close attention to the residual chlorine level, pH and COD level during treatment for optimal efficacy.
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evaluation of the microbiological safety and quality of vietnamese Pangasius hypophthalmus during processing by a microbial assessment scheme in combination with a self assessment questionnaire
Fisheries Science, 2014Co-Authors: Anh Ngoc Tong Thi, Simbarashe Samapundo, Marc Heyndrickx, Binh Ly Nguyen, Liesbeth Jacxsens, Bert Noseda, Frank DevlieghereAbstract:Pangasius hypophthalmus (referred to as Pangasius or tra fish in Vietnam) has become highly appreciated by consumers in the European Union, USA, Japan, etc. and is of worldwide economic importance. Therefore, the microbial quality and safety of Pangasius fish processed for export was assessed by means of a microbial assessment scheme throughout the entire production process. A total of 144 samples were collected from various processing steps and analyzed. It was determined that the microbial safety and quality of the products was not guaranteed as the contamination levels remained high throughout processing. Escherichia coli, Staphylococcus aureus and Vibrio cholerae were present on the hands of food operators, particularly those in the packaging area. Moreover, the presence of Listeria monocytogenes (1 positive out of 9 samples) and V. cholerae (4/9) on the final products was likely a result of inadequate hygiene practices in the processing environment. Also discussed in this paper are the results of a self-assessment questionnaire, which provide insight into the performance of the food safety management system currently implemented at the company. These data are of major importance in order to contribute valuable information to the local and international trade point of view in general and to the intended customers in particular.
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microbial ecology of vietnamese tra fish Pangasius hypophthalmus fillets during processing
Applied Biological Sciences 19th National symposium Abstracts, 2014Co-Authors: Anh Ngoc Tong Thi, Simbarashe Samapundo, Marc Heyndrickx, Binh Ly Nguyen, Bert Noseda, Katrien Broekaert, Geertrui Rasschaert, Frank DevlieghereAbstract:Distribution microbiota of tropical-farmed Pangasius hypophthalmus fish during processing was examined by culture-dependent techniques and 16S rRNA gene sequencing. Two Vietnamese companies (BC: large scale factory, chlorine-based process, BW: large scale factory, water-based process and SC: small scale factory, chlorine-based process) processed Pangasius for intend-exporting to Western market was sampled. A total of 252 isolates originating from beginning, intermediate and final steps of the production line were then identified by 16S rRNA gene sequencing. The results of microbial profile showed no significant difference (p > 0.05) between two processing lines of BC and BW. Surprisingly, chlorine treated fillets from the SC line were revealed to have significantly higher microbial counts than potable water treated fillets at BW line due to probably temperature abuse during processing. Along the processing chains, 131 of Gram negative and 43 of Gram positive bacteria were identified consisting of 20 different genera and 38 different species. Contrary to microbial counts, the type of spoilage related microbiota present on the BC and BW line was more diverse than that on the SC line. Enterobacteriaceae (as spoilage and hygiene indicators) such as Providencia, Shigella, Klebsiella, Enterobacter and Wautersiella were isolated from fillets sampled on the SC line whereas Serratia was only observed on fillets sampled on the BC and BW lines. The results can be used to improve Good Manufacturing Practices for processed Pangasius fillets.
Frank Devlieghere - One of the best experts on this subject based on the ideXlab platform.
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microbiota of frozen vietnamese catfish Pangasius hypophthalmus marketed in belgium
International Journal of Food Contamination, 2016Co-Authors: Anh Ngoc Tong Thi, Simbarashe Samapundo, Frank Devlieghere, Marc HeyndrickxAbstract:Vietnamese catfish (Pangasius hypophthalmus) is highly appreciated in many European countries, the U.S., Canada, Japan etc. This paper presents an overview of the microbiota of frozen Vietnamese catfish products marketed in Belgium. Samples of Pangasius steaks, portions and fillets from six brands were collected from supermarkets located in Ghent, Belgium. The total psychrotrophic and mesophilic aerobic counts of the samples evaluated from each brand did not differ significantly (p > 0.05) and ranged from 3.8-5.2 log CFU/g and 3.8-4.8 log CFU/g, respectively. Lactic acid bacteria counts varied from 2.2 to 4.1 log CFU/g while the counts of presumptive Enterobacteriaceae ranged from 1.6 to 3.8 log CFU/g. A total of 132 isolates were collected from the plates used to enumerate the microbial parameters mentioned above. Fourteen different genera and 18 different species were identified by means of 16S rRNA gene sequencing. The most prevalent genera of Lactococcus (31.2 %), Staphylococcus (11.7 %), Serratia (10.4 %), Acinetobacter (9.1 %), Enterococcus (7.8 %) and Pseudomonas spp. (6.5 %) were identified by means of 16S rRNA gene sequencing. The results obtained provide an overview of the dominant microbiota on frozen Pangasius which is useful for the development of appropriate preservation techniques for thawed Pangasius products.
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evaluation of the safety and quality of wash water during the batch washing of Pangasius fish Pangasius hypophthalmus in chlorinated and non chlorinated water
Lwt - Food Science and Technology, 2016Co-Authors: Anh Ngoc Tong Thi, Imca Sampers, Sam Van Haute, Simbarashe Samapundo, Bruno De Meulenaer, Marc Heyndrickx, Frank DevlieghereAbstract:Abstract This study investigated the continuous dosing of chlorine to the wash water by means of a pump to maintain antimicrobial levels of free chlorine in the wash water during the washing of 12 batches of Pangasius fillets. In comparison to the control (no chlorination), total psychrotrophic bacteria were reduced by between 2 and 4 log CFU/100 ml. After the final batch was washed, total chlorine and organic matter in the water sampled had accumulated to 482.9 ± 17.0 ppm and 4447.5 ± 187.4 mg O 2 /L, respectively. However, only 8.9 ± 1.3 μg/L of trihalomethanes was formed in the chlorinated wash water whereas no trihalomethanes were detected in the washed Pangasius fillets after rinsing. It was concluded that the Pangasius fillets washed in chlorinated water continuously dosed with chlorine were safe for human consumption even after a throughput of 12 batches. However, the organoleptic properties of Pangasius fillets washed in the final batch differed significantly from those washed earlier batches.
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decontamination of Pangasius fish Pangasius hypophthalmus with chlorine or peracetic acid in the laboratory and in a vietnamese processing company
International Journal of Food Microbiology, 2015Co-Authors: Anh Ngoc Tong Thi, Imca Sampers, Sam Van Haute, Simbarashe Samapundo, Marc Heyndrickx, Binh Ly Nguyen, Frank DevlieghereAbstract:Abstract This study evaluated the decontamination of Pangasius fillets in chlorine or peracetic acid treated wash water. First, the decontamination efficacy of the washing step with chlorinated water applied by a Vietnamese processing company during trimming of Pangasius fillets was evaluated and used as the basis for the experiments performed on a laboratory scale. As chlorine was only added at the beginning of the batch and used continuously without renewal for 239 min; a rapid increase of the bacterial counts and a fast decrease of chlorine in the wash water were found. This could be explained by the rapid accumulation of organic matter (ca. 400 mg O 2 /L of COD after only 24 min). Secondly, for the experiments performed on a laboratory scale, a single batch approach (one batch of wash water for treating a fillet) was used. Chlorine and PAA were evaluated at 10, 20, 50 and 150 ppm at contact times of 10, 20 and 240 s. Washing with chlorine and PAA wash water resulted in a reduction of Escherichia coli on Pangasius fish which ranged from 0–1.0 and 0.4–1.4 log CFU/g, respectively while less to no reduction of total psychrotrophic counts, lactic acid bacteria and coliforms on Pangasius fish was observed. However, in comparison to PAA, chlorine was lost rapidly. As an example, 53–83% of chlorine and 15–17% of PAA were lost after washing for 40 s (COD = 238.2 ± 66.3 mg O 2 /L). Peracetic acid can therefore be an alternative sanitizer. However, its higher cost will have to be taken into consideration. Where (cheaper) chlorine is used, the processors have to pay close attention to the residual chlorine level, pH and COD level during treatment for optimal efficacy.
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evaluation of the microbiological safety and quality of vietnamese Pangasius hypophthalmus during processing by a microbial assessment scheme in combination with a self assessment questionnaire
Fisheries Science, 2014Co-Authors: Anh Ngoc Tong Thi, Simbarashe Samapundo, Marc Heyndrickx, Binh Ly Nguyen, Liesbeth Jacxsens, Bert Noseda, Frank DevlieghereAbstract:Pangasius hypophthalmus (referred to as Pangasius or tra fish in Vietnam) has become highly appreciated by consumers in the European Union, USA, Japan, etc. and is of worldwide economic importance. Therefore, the microbial quality and safety of Pangasius fish processed for export was assessed by means of a microbial assessment scheme throughout the entire production process. A total of 144 samples were collected from various processing steps and analyzed. It was determined that the microbial safety and quality of the products was not guaranteed as the contamination levels remained high throughout processing. Escherichia coli, Staphylococcus aureus and Vibrio cholerae were present on the hands of food operators, particularly those in the packaging area. Moreover, the presence of Listeria monocytogenes (1 positive out of 9 samples) and V. cholerae (4/9) on the final products was likely a result of inadequate hygiene practices in the processing environment. Also discussed in this paper are the results of a self-assessment questionnaire, which provide insight into the performance of the food safety management system currently implemented at the company. These data are of major importance in order to contribute valuable information to the local and international trade point of view in general and to the intended customers in particular.
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microbial ecology of vietnamese tra fish Pangasius hypophthalmus fillets during processing
Applied Biological Sciences 19th National symposium Abstracts, 2014Co-Authors: Anh Ngoc Tong Thi, Simbarashe Samapundo, Marc Heyndrickx, Binh Ly Nguyen, Bert Noseda, Katrien Broekaert, Geertrui Rasschaert, Frank DevlieghereAbstract:Distribution microbiota of tropical-farmed Pangasius hypophthalmus fish during processing was examined by culture-dependent techniques and 16S rRNA gene sequencing. Two Vietnamese companies (BC: large scale factory, chlorine-based process, BW: large scale factory, water-based process and SC: small scale factory, chlorine-based process) processed Pangasius for intend-exporting to Western market was sampled. A total of 252 isolates originating from beginning, intermediate and final steps of the production line were then identified by 16S rRNA gene sequencing. The results of microbial profile showed no significant difference (p > 0.05) between two processing lines of BC and BW. Surprisingly, chlorine treated fillets from the SC line were revealed to have significantly higher microbial counts than potable water treated fillets at BW line due to probably temperature abuse during processing. Along the processing chains, 131 of Gram negative and 43 of Gram positive bacteria were identified consisting of 20 different genera and 38 different species. Contrary to microbial counts, the type of spoilage related microbiota present on the BC and BW line was more diverse than that on the SC line. Enterobacteriaceae (as spoilage and hygiene indicators) such as Providencia, Shigella, Klebsiella, Enterobacter and Wautersiella were isolated from fillets sampled on the SC line whereas Serratia was only observed on fillets sampled on the BC and BW lines. The results can be used to improve Good Manufacturing Practices for processed Pangasius fillets.
Chongrak Polprasert - One of the best experts on this subject based on the ideXlab platform.
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determination and health risk assessment of enrofloxacin flumequine and sulfamethoxazole in imported Pangasius catfish products in thailand
Journal of Environmental Science and Health Part B-pesticides Food Contaminants and Agricultural Wastes, 2018Co-Authors: Worawat Jansomboon, Suwanna Kitpati Boontanon, Narin Boontanon, Chongrak PolprasertAbstract:ABSTRACTThe goals of this study were to determine the levels of three antibiotics – enrofloxacin, flumequine and sulfamethoxazole – in Pangasius catfish products imported into Thailand and to assess the health risks from consumption. To extract these antibiotic residues, acetonitrile, methanol and a small amount of formic acid were used as solvents. Determination of the antibiotics after extraction steps was carried out by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) technique. The results showed that 14 and 3 samples of Pangasius catfish products were contaminated with enrofloxacin and sulfamethoxazole, respectively. No flumequine residue was found. While the concentration levels of these antibiotics in most contaminated samples were lower than the European Union (EU) standard, one sample was found to contain sulfamethoxazole at 245.91 µg kg−1, which was higher than the EU standard (100 µg kg−1), indicating the likelihood that some contaminated freshwater fish products are widel...
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monitoring and determination of sulfonamide antibiotics sulfamethoxydiazine sulfamethazine sulfamethoxazole and sulfadiazine in imported Pangasius catfish products in thailand using liquid chromatography coupled with tandem mass spectrometry
Food Chemistry, 2016Co-Authors: Worawat Jansomboon, Suwanna Kitpati Boontanon, Narin Boontanon, Chongrak PolprasertAbstract:This research aimed to monitor the concentrations of sulfamethoxydiazine (SMD), sulfamethazine (SMT), sulfamethoxazole (SMX) and sulfadiazine (SDZ) in imported Pangasius catfish products in Thailand. The residues of the four sulfonamides (SAs) were analyzed by extraction process and liquid chromatography coupled with tandem mass spectrometry. The highest concentrations found were 10.97ng/g for SMD, 6.23ng/g for SMT, 11.13ng/g for SDZ and 245.91ng/g for SMX, which was higher than the European Union (EU) standard (100ng/g). Moreover, all samples contaminated with SMX also contained SMT, indicating that more than one antibiotic was used for production in the country of origin. Because Thai standards for antibiotics in food have not been completely set, all contaminated discovered would not be considered to be an illegal food, in which antibiotic residues may affect human health in the long term. Therefore, antibiotic residues in Pangasius catfish products should be continually regulated and monitored.
Marc Heyndrickx - One of the best experts on this subject based on the ideXlab platform.
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microbiota of frozen vietnamese catfish Pangasius hypophthalmus marketed in belgium
International Journal of Food Contamination, 2016Co-Authors: Anh Ngoc Tong Thi, Simbarashe Samapundo, Frank Devlieghere, Marc HeyndrickxAbstract:Vietnamese catfish (Pangasius hypophthalmus) is highly appreciated in many European countries, the U.S., Canada, Japan etc. This paper presents an overview of the microbiota of frozen Vietnamese catfish products marketed in Belgium. Samples of Pangasius steaks, portions and fillets from six brands were collected from supermarkets located in Ghent, Belgium. The total psychrotrophic and mesophilic aerobic counts of the samples evaluated from each brand did not differ significantly (p > 0.05) and ranged from 3.8-5.2 log CFU/g and 3.8-4.8 log CFU/g, respectively. Lactic acid bacteria counts varied from 2.2 to 4.1 log CFU/g while the counts of presumptive Enterobacteriaceae ranged from 1.6 to 3.8 log CFU/g. A total of 132 isolates were collected from the plates used to enumerate the microbial parameters mentioned above. Fourteen different genera and 18 different species were identified by means of 16S rRNA gene sequencing. The most prevalent genera of Lactococcus (31.2 %), Staphylococcus (11.7 %), Serratia (10.4 %), Acinetobacter (9.1 %), Enterococcus (7.8 %) and Pseudomonas spp. (6.5 %) were identified by means of 16S rRNA gene sequencing. The results obtained provide an overview of the dominant microbiota on frozen Pangasius which is useful for the development of appropriate preservation techniques for thawed Pangasius products.
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evaluation of the safety and quality of wash water during the batch washing of Pangasius fish Pangasius hypophthalmus in chlorinated and non chlorinated water
Lwt - Food Science and Technology, 2016Co-Authors: Anh Ngoc Tong Thi, Imca Sampers, Sam Van Haute, Simbarashe Samapundo, Bruno De Meulenaer, Marc Heyndrickx, Frank DevlieghereAbstract:Abstract This study investigated the continuous dosing of chlorine to the wash water by means of a pump to maintain antimicrobial levels of free chlorine in the wash water during the washing of 12 batches of Pangasius fillets. In comparison to the control (no chlorination), total psychrotrophic bacteria were reduced by between 2 and 4 log CFU/100 ml. After the final batch was washed, total chlorine and organic matter in the water sampled had accumulated to 482.9 ± 17.0 ppm and 4447.5 ± 187.4 mg O 2 /L, respectively. However, only 8.9 ± 1.3 μg/L of trihalomethanes was formed in the chlorinated wash water whereas no trihalomethanes were detected in the washed Pangasius fillets after rinsing. It was concluded that the Pangasius fillets washed in chlorinated water continuously dosed with chlorine were safe for human consumption even after a throughput of 12 batches. However, the organoleptic properties of Pangasius fillets washed in the final batch differed significantly from those washed earlier batches.
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decontamination of Pangasius fish Pangasius hypophthalmus with chlorine or peracetic acid in the laboratory and in a vietnamese processing company
International Journal of Food Microbiology, 2015Co-Authors: Anh Ngoc Tong Thi, Imca Sampers, Sam Van Haute, Simbarashe Samapundo, Marc Heyndrickx, Binh Ly Nguyen, Frank DevlieghereAbstract:Abstract This study evaluated the decontamination of Pangasius fillets in chlorine or peracetic acid treated wash water. First, the decontamination efficacy of the washing step with chlorinated water applied by a Vietnamese processing company during trimming of Pangasius fillets was evaluated and used as the basis for the experiments performed on a laboratory scale. As chlorine was only added at the beginning of the batch and used continuously without renewal for 239 min; a rapid increase of the bacterial counts and a fast decrease of chlorine in the wash water were found. This could be explained by the rapid accumulation of organic matter (ca. 400 mg O 2 /L of COD after only 24 min). Secondly, for the experiments performed on a laboratory scale, a single batch approach (one batch of wash water for treating a fillet) was used. Chlorine and PAA were evaluated at 10, 20, 50 and 150 ppm at contact times of 10, 20 and 240 s. Washing with chlorine and PAA wash water resulted in a reduction of Escherichia coli on Pangasius fish which ranged from 0–1.0 and 0.4–1.4 log CFU/g, respectively while less to no reduction of total psychrotrophic counts, lactic acid bacteria and coliforms on Pangasius fish was observed. However, in comparison to PAA, chlorine was lost rapidly. As an example, 53–83% of chlorine and 15–17% of PAA were lost after washing for 40 s (COD = 238.2 ± 66.3 mg O 2 /L). Peracetic acid can therefore be an alternative sanitizer. However, its higher cost will have to be taken into consideration. Where (cheaper) chlorine is used, the processors have to pay close attention to the residual chlorine level, pH and COD level during treatment for optimal efficacy.
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evaluation of the microbiological safety and quality of vietnamese Pangasius hypophthalmus during processing by a microbial assessment scheme in combination with a self assessment questionnaire
Fisheries Science, 2014Co-Authors: Anh Ngoc Tong Thi, Simbarashe Samapundo, Marc Heyndrickx, Binh Ly Nguyen, Liesbeth Jacxsens, Bert Noseda, Frank DevlieghereAbstract:Pangasius hypophthalmus (referred to as Pangasius or tra fish in Vietnam) has become highly appreciated by consumers in the European Union, USA, Japan, etc. and is of worldwide economic importance. Therefore, the microbial quality and safety of Pangasius fish processed for export was assessed by means of a microbial assessment scheme throughout the entire production process. A total of 144 samples were collected from various processing steps and analyzed. It was determined that the microbial safety and quality of the products was not guaranteed as the contamination levels remained high throughout processing. Escherichia coli, Staphylococcus aureus and Vibrio cholerae were present on the hands of food operators, particularly those in the packaging area. Moreover, the presence of Listeria monocytogenes (1 positive out of 9 samples) and V. cholerae (4/9) on the final products was likely a result of inadequate hygiene practices in the processing environment. Also discussed in this paper are the results of a self-assessment questionnaire, which provide insight into the performance of the food safety management system currently implemented at the company. These data are of major importance in order to contribute valuable information to the local and international trade point of view in general and to the intended customers in particular.
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microbial ecology of vietnamese tra fish Pangasius hypophthalmus fillets during processing
Applied Biological Sciences 19th National symposium Abstracts, 2014Co-Authors: Anh Ngoc Tong Thi, Simbarashe Samapundo, Marc Heyndrickx, Binh Ly Nguyen, Bert Noseda, Katrien Broekaert, Geertrui Rasschaert, Frank DevlieghereAbstract:Distribution microbiota of tropical-farmed Pangasius hypophthalmus fish during processing was examined by culture-dependent techniques and 16S rRNA gene sequencing. Two Vietnamese companies (BC: large scale factory, chlorine-based process, BW: large scale factory, water-based process and SC: small scale factory, chlorine-based process) processed Pangasius for intend-exporting to Western market was sampled. A total of 252 isolates originating from beginning, intermediate and final steps of the production line were then identified by 16S rRNA gene sequencing. The results of microbial profile showed no significant difference (p > 0.05) between two processing lines of BC and BW. Surprisingly, chlorine treated fillets from the SC line were revealed to have significantly higher microbial counts than potable water treated fillets at BW line due to probably temperature abuse during processing. Along the processing chains, 131 of Gram negative and 43 of Gram positive bacteria were identified consisting of 20 different genera and 38 different species. Contrary to microbial counts, the type of spoilage related microbiota present on the BC and BW line was more diverse than that on the SC line. Enterobacteriaceae (as spoilage and hygiene indicators) such as Providencia, Shigella, Klebsiella, Enterobacter and Wautersiella were isolated from fillets sampled on the SC line whereas Serratia was only observed on fillets sampled on the BC and BW lines. The results can be used to improve Good Manufacturing Practices for processed Pangasius fillets.
Simbarashe Samapundo - One of the best experts on this subject based on the ideXlab platform.
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microbiota of frozen vietnamese catfish Pangasius hypophthalmus marketed in belgium
International Journal of Food Contamination, 2016Co-Authors: Anh Ngoc Tong Thi, Simbarashe Samapundo, Frank Devlieghere, Marc HeyndrickxAbstract:Vietnamese catfish (Pangasius hypophthalmus) is highly appreciated in many European countries, the U.S., Canada, Japan etc. This paper presents an overview of the microbiota of frozen Vietnamese catfish products marketed in Belgium. Samples of Pangasius steaks, portions and fillets from six brands were collected from supermarkets located in Ghent, Belgium. The total psychrotrophic and mesophilic aerobic counts of the samples evaluated from each brand did not differ significantly (p > 0.05) and ranged from 3.8-5.2 log CFU/g and 3.8-4.8 log CFU/g, respectively. Lactic acid bacteria counts varied from 2.2 to 4.1 log CFU/g while the counts of presumptive Enterobacteriaceae ranged from 1.6 to 3.8 log CFU/g. A total of 132 isolates were collected from the plates used to enumerate the microbial parameters mentioned above. Fourteen different genera and 18 different species were identified by means of 16S rRNA gene sequencing. The most prevalent genera of Lactococcus (31.2 %), Staphylococcus (11.7 %), Serratia (10.4 %), Acinetobacter (9.1 %), Enterococcus (7.8 %) and Pseudomonas spp. (6.5 %) were identified by means of 16S rRNA gene sequencing. The results obtained provide an overview of the dominant microbiota on frozen Pangasius which is useful for the development of appropriate preservation techniques for thawed Pangasius products.
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evaluation of the safety and quality of wash water during the batch washing of Pangasius fish Pangasius hypophthalmus in chlorinated and non chlorinated water
Lwt - Food Science and Technology, 2016Co-Authors: Anh Ngoc Tong Thi, Imca Sampers, Sam Van Haute, Simbarashe Samapundo, Bruno De Meulenaer, Marc Heyndrickx, Frank DevlieghereAbstract:Abstract This study investigated the continuous dosing of chlorine to the wash water by means of a pump to maintain antimicrobial levels of free chlorine in the wash water during the washing of 12 batches of Pangasius fillets. In comparison to the control (no chlorination), total psychrotrophic bacteria were reduced by between 2 and 4 log CFU/100 ml. After the final batch was washed, total chlorine and organic matter in the water sampled had accumulated to 482.9 ± 17.0 ppm and 4447.5 ± 187.4 mg O 2 /L, respectively. However, only 8.9 ± 1.3 μg/L of trihalomethanes was formed in the chlorinated wash water whereas no trihalomethanes were detected in the washed Pangasius fillets after rinsing. It was concluded that the Pangasius fillets washed in chlorinated water continuously dosed with chlorine were safe for human consumption even after a throughput of 12 batches. However, the organoleptic properties of Pangasius fillets washed in the final batch differed significantly from those washed earlier batches.
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decontamination of Pangasius fish Pangasius hypophthalmus with chlorine or peracetic acid in the laboratory and in a vietnamese processing company
International Journal of Food Microbiology, 2015Co-Authors: Anh Ngoc Tong Thi, Imca Sampers, Sam Van Haute, Simbarashe Samapundo, Marc Heyndrickx, Binh Ly Nguyen, Frank DevlieghereAbstract:Abstract This study evaluated the decontamination of Pangasius fillets in chlorine or peracetic acid treated wash water. First, the decontamination efficacy of the washing step with chlorinated water applied by a Vietnamese processing company during trimming of Pangasius fillets was evaluated and used as the basis for the experiments performed on a laboratory scale. As chlorine was only added at the beginning of the batch and used continuously without renewal for 239 min; a rapid increase of the bacterial counts and a fast decrease of chlorine in the wash water were found. This could be explained by the rapid accumulation of organic matter (ca. 400 mg O 2 /L of COD after only 24 min). Secondly, for the experiments performed on a laboratory scale, a single batch approach (one batch of wash water for treating a fillet) was used. Chlorine and PAA were evaluated at 10, 20, 50 and 150 ppm at contact times of 10, 20 and 240 s. Washing with chlorine and PAA wash water resulted in a reduction of Escherichia coli on Pangasius fish which ranged from 0–1.0 and 0.4–1.4 log CFU/g, respectively while less to no reduction of total psychrotrophic counts, lactic acid bacteria and coliforms on Pangasius fish was observed. However, in comparison to PAA, chlorine was lost rapidly. As an example, 53–83% of chlorine and 15–17% of PAA were lost after washing for 40 s (COD = 238.2 ± 66.3 mg O 2 /L). Peracetic acid can therefore be an alternative sanitizer. However, its higher cost will have to be taken into consideration. Where (cheaper) chlorine is used, the processors have to pay close attention to the residual chlorine level, pH and COD level during treatment for optimal efficacy.
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evaluation of the microbiological safety and quality of vietnamese Pangasius hypophthalmus during processing by a microbial assessment scheme in combination with a self assessment questionnaire
Fisheries Science, 2014Co-Authors: Anh Ngoc Tong Thi, Simbarashe Samapundo, Marc Heyndrickx, Binh Ly Nguyen, Liesbeth Jacxsens, Bert Noseda, Frank DevlieghereAbstract:Pangasius hypophthalmus (referred to as Pangasius or tra fish in Vietnam) has become highly appreciated by consumers in the European Union, USA, Japan, etc. and is of worldwide economic importance. Therefore, the microbial quality and safety of Pangasius fish processed for export was assessed by means of a microbial assessment scheme throughout the entire production process. A total of 144 samples were collected from various processing steps and analyzed. It was determined that the microbial safety and quality of the products was not guaranteed as the contamination levels remained high throughout processing. Escherichia coli, Staphylococcus aureus and Vibrio cholerae were present on the hands of food operators, particularly those in the packaging area. Moreover, the presence of Listeria monocytogenes (1 positive out of 9 samples) and V. cholerae (4/9) on the final products was likely a result of inadequate hygiene practices in the processing environment. Also discussed in this paper are the results of a self-assessment questionnaire, which provide insight into the performance of the food safety management system currently implemented at the company. These data are of major importance in order to contribute valuable information to the local and international trade point of view in general and to the intended customers in particular.
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microbial ecology of vietnamese tra fish Pangasius hypophthalmus fillets during processing
Applied Biological Sciences 19th National symposium Abstracts, 2014Co-Authors: Anh Ngoc Tong Thi, Simbarashe Samapundo, Marc Heyndrickx, Binh Ly Nguyen, Bert Noseda, Katrien Broekaert, Geertrui Rasschaert, Frank DevlieghereAbstract:Distribution microbiota of tropical-farmed Pangasius hypophthalmus fish during processing was examined by culture-dependent techniques and 16S rRNA gene sequencing. Two Vietnamese companies (BC: large scale factory, chlorine-based process, BW: large scale factory, water-based process and SC: small scale factory, chlorine-based process) processed Pangasius for intend-exporting to Western market was sampled. A total of 252 isolates originating from beginning, intermediate and final steps of the production line were then identified by 16S rRNA gene sequencing. The results of microbial profile showed no significant difference (p > 0.05) between two processing lines of BC and BW. Surprisingly, chlorine treated fillets from the SC line were revealed to have significantly higher microbial counts than potable water treated fillets at BW line due to probably temperature abuse during processing. Along the processing chains, 131 of Gram negative and 43 of Gram positive bacteria were identified consisting of 20 different genera and 38 different species. Contrary to microbial counts, the type of spoilage related microbiota present on the BC and BW line was more diverse than that on the SC line. Enterobacteriaceae (as spoilage and hygiene indicators) such as Providencia, Shigella, Klebsiella, Enterobacter and Wautersiella were isolated from fillets sampled on the SC line whereas Serratia was only observed on fillets sampled on the BC and BW lines. The results can be used to improve Good Manufacturing Practices for processed Pangasius fillets.
