The Experts below are selected from a list of 30933 Experts worldwide ranked by ideXlab platform
Paw Dalgaard - One of the best experts on this subject based on the ideXlab platform.
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identification of lactic acid bacteria from Spoilage associations of cooked and brined shrimps stored under modified atmosphere between 0 degrees c and 25 degrees c
Journal of Applied Microbiology, 2003Co-Authors: Paw Dalgaard, Marc Vancanneyt, Jean Swings, Euras N Vilalta, P Fruekilde, J J LeisnerAbstract:Aims: To evaluate Spoilage and identify lactic acid bacteria (LAB) from Spoilage associations of cooked and brined shrimps stored under modified atmosphere packaging (MAP) at 0, 5, 8, 15 and 25°C. Methods and Results: Bacterial isolates (102) from Spoilage associations of cooked and brined MAP shrimps were characterized by phenotypic tests and identified as lactic acid bacteria (78 isolates), other Gram-positive bacteria (13 isolates) and Gram-negative bacteria (11 isolates). A selection of 48 LAB isolates were further characterized and identified by phenotypic tests and SDS-PAGE electrophoresis of whole cell proteins. Selected clusters of LAB isolates were analysed by plasmid profiling, pulsed field gel electrophoresis and 16S rRNA gene sequencing. Enterococcus faecalis was identified in Spoilage associations at 15°C and 25°C, and its metabolic activity corresponded to chemical changes in spoiled products. Carnobacterium divergens, a non-motile Carnobacterium sp. nov. and Lactobacillus curvatus were the LAB species observed in Spoilage associations of products stored at 0°C, 5°C and 8°C. Conclusions:Enterococcus spp. and Carnobacterium spp. were the dominant parts of Spoilage associations of cooked and brined MAP shrimps stored at high and low temperatures, respectively. Significance and Impact of the Study: The SDS-PAGE technique and simple biochemical keys allowed the majority of LAB isolates from Spoilage associations of cooked and brined MAP shrimps to be identified at the species level.
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fish Spoilage bacteria problems and solutions
Current Opinion in Biotechnology, 2002Co-Authors: Lone Gram, Paw DalgaardAbstract:Abstract Microorganisms are the major cause of Spoilage of most seafood products. However, only a few members of the microbial community, the specific Spoilage organisms (SSOs), give rise to the offensive off-flavours associated with seafood Spoilage. Combining microbial ecology, molecular techniques, analytical chemistry, sensory analysis and mathematical modelling allows us to characterise the SSOs and to develop methods to determine, predict and extend the shelf life of products.
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the effect of biogenic amine production by single bacterial cultures and metabiosis on cold smoked salmon
Journal of Applied Microbiology, 2000Co-Authors: Lasse Vigel Jorgensen, Hans Henrik Huss, Paw DalgaardAbstract:Aim: Biogenic amines are important indicators of Spoilage in vacuum-packed cold-smoked salmon. It is the aim of this study to identify bacteria responsible for biogenic amine production in cold-smoked salmon. Methods and Results: The present study identified Spoilage microflora from cold-smoked salmon and determined biogenic amine production of single and co-cultures growing in cold-smoked salmon. Photobacterium phosphoreum was the only species that produced histamine when inoculated on sterile cold-smoked salmon. Production of putrescine was enhanced 10–15 times when cultures of Serratia liquefaciens or Hafnia alvei were grown with Carnobacterium divergens or Lactobacillus sakei subsp. carnosus. This phenomenon was explained by interspecies microbial metabolism of arginine, i.e., metabiosis. Conclusions: The amounts of biogenic amines produced by single and co-cultures corresponded to those observed during Spoilage of naturally-contaminated cold-smoked salmon. Photobacterium phosphoreum and Lact. curvatus were identified as the specific Spoilage organisms in cold-smoked salmon. Significance and Impact of the Study: Determination of the specific Spoilage organism is needed before a model can be developed for shelf-life predictions of cold-smoked salmon.
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multiple compound quality index for cold smoked salmon salmo salar developed by multivariate regression of biogenic amines and ph
Journal of Agricultural and Food Chemistry, 2000Co-Authors: Lasse Vigel Jorgensen, Paw Dalgaard, Hans Henrik HussAbstract:Production of biogenic amines during chill storage of 12 lots of cold-smoked salmon was studied. These data allowed for a multiple compound quality index to be developed by multivariate regression (partial least square regression). The quality index was based on concentrations of cadaverine, histamine, putrescine, and tyramine and pH and showed good correlation with sensory assessments. Biogenic amines were indicators of Spoilage rather than casual agents of Spoilage off-flavors. Four different biogenic amine profiles were found at the time of Spoilage in cold-smoked salmon. These were the results of differences in the Spoilage microflora. Histamine was detected above regulatory limits but below toxic levels. Measurements of salt and dry matter for calculation of water phase salt could be substituted by rapid water activity measurements. Keywords: Agmatine; cadaverine; putrescine; histamine; tyramine; partial least squares regression; Spoilage; water activity
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qualitative and quantitative characterization of Spoilage bacteria from packed fish
International Journal of Food Microbiology, 1995Co-Authors: Paw DalgaardAbstract:Abstract The large cells recently suggested to be responsible for Spoilage of packed cod, have been identified as Photobacterium phosphoreum. The Spoilage activity of these cells, of Shewanella. putrefaciens and of other microorganisms isolated form spoiled packed cod has been studied. Both qualitative and quantitative tests were used for characterization of the microbial Spoilage activity. The importance of the different groups of microorganisms was evaluated by comparison of microbial Spoilage activity determined in model substrates and in product experiments. The yield factor for production of trimethylamine (YTMA/CFU) and the cell concentration determined at the time of off-odour detection were used as quantitative measurements of microbial Spoilage activity. On average cells of P. Phosphoreum produced 30 times more TMA than cells of S. putrefaciens, YTMA/CFU of the two organisms were 10−8.0 mg-N TMA cfu and 10−9.5 mg-N TMA cfu , respectively. With these yield factors the level of TMA found in spoiled packed cod (30 mg-N TMA 100g ) corresponds to about 107 cfu g of P. phosphoreum and to 108–109 cfu g of S. putrefaciens. 107 cfu g of P. phosphoreum were actually found in spoiled packed cod suggesting this organism could be responsible for Spoilage. High cell concentrations of more than 108 cfu g of S. putrefaciens were required for production of detectable off-odours and is was concluded that this organism is without importance for Spoilage of packed cod.
Lotta Kuuliala - One of the best experts on this subject based on the ideXlab platform.
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microbiological chemical and sensory Spoilage analysis of raw atlantic cod gadus morhua stored under modified atmospheres
Food Microbiology, 2018Co-Authors: Lotta Kuuliala, Al Y Hage, Angelosgerasimos Ioannidis, Marc Sader, Frederiekmaarten Kerckhof, Mike Vanderroost, Nico Boon, B De Baets, B De Meulenaer, Peter RagaertAbstract:During fish Spoilage, microbial metabolism leads to the production of volatile organic compounds (VOCs), characteristic off-odors and eventual consumer rejection. The aim of the present study was to contribute to the development of intelligent packaging technologies by identifying and quantifying VOCs that indicate Spoilage of raw Atlantic cod (Gadus morhua) under atmospheres (% v/v CO2/O-2/N-2) 60/40/0, 60/5/35 and air. Spoilage was examined by microbiological, chemical and sensory analyses over storage time at 4 or 8 degrees C. Selected-ion flow-tube mass spectrometry (SIFT-MS) was used for quantifying selected VOCs and amplicon sequencing of the 16S rRNA gene was used for the characterization of the cod microbiota. OTUs classified within the Photobacterium genus increased in relative abundance over time under all storage conditions, suggesting that Photobacterium contributed to Spoilage and VOC production. The onset of exponential VOC concentration increase and sensory rejection occurred at high total plate counts (7-7.5 log). Monitoring of early Spoilage thus calls for sensitivity for low VOC concentrations. (c) 2017 Elsevier Ltd. All rights reserved.
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microbiological chemical and sensory Spoilage analysis of raw atlantic cod gadus morhua stored under modified atmospheres
Food Microbiology, 2018Co-Authors: Lotta Kuuliala, Al Y Hage, Angelosgerasimos Ioannidis, Marc Sader, Frederiekmaarten Kerckhof, Mike Vanderroost, Nico Boon, B De Baets, B De MeulenaerAbstract:Abstract During fish Spoilage, microbial metabolism leads to the production of volatile organic compounds (VOCs), characteristic off-odors and eventual consumer rejection. The aim of the present study was to contribute to the development of intelligent packaging technologies by identifying and quantifying VOCs that indicate Spoilage of raw Atlantic cod (Gadus morhua) under atmospheres (%v/v CO2/O2/N2) 60/40/0, 60/5/35 and air. Spoilage was examined by microbiological, chemical and sensory analyses over storage time at 4 or 8 °C. Selected-ion flow-tube mass spectrometry (SIFT-MS) was used for quantifying selected VOCs and amplicon sequencing of the 16S rRNA gene was used for the characterization of the cod microbiota. OTUs classified within the Photobacterium genus increased in relative abundance over time under all storage conditions, suggesting that Photobacterium contributed to Spoilage and VOC production. The onset of exponential VOC concentration increase and sensory rejection occurred at high total plate counts (7–7.5 log). Monitoring of early Spoilage thus calls for sensitivity for low VOC concentrations.
B De Meulenaer - One of the best experts on this subject based on the ideXlab platform.
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microbiological chemical and sensory Spoilage analysis of raw atlantic cod gadus morhua stored under modified atmospheres
Food Microbiology, 2018Co-Authors: Lotta Kuuliala, Al Y Hage, Angelosgerasimos Ioannidis, Marc Sader, Frederiekmaarten Kerckhof, Mike Vanderroost, Nico Boon, B De Baets, B De Meulenaer, Peter RagaertAbstract:During fish Spoilage, microbial metabolism leads to the production of volatile organic compounds (VOCs), characteristic off-odors and eventual consumer rejection. The aim of the present study was to contribute to the development of intelligent packaging technologies by identifying and quantifying VOCs that indicate Spoilage of raw Atlantic cod (Gadus morhua) under atmospheres (% v/v CO2/O-2/N-2) 60/40/0, 60/5/35 and air. Spoilage was examined by microbiological, chemical and sensory analyses over storage time at 4 or 8 degrees C. Selected-ion flow-tube mass spectrometry (SIFT-MS) was used for quantifying selected VOCs and amplicon sequencing of the 16S rRNA gene was used for the characterization of the cod microbiota. OTUs classified within the Photobacterium genus increased in relative abundance over time under all storage conditions, suggesting that Photobacterium contributed to Spoilage and VOC production. The onset of exponential VOC concentration increase and sensory rejection occurred at high total plate counts (7-7.5 log). Monitoring of early Spoilage thus calls for sensitivity for low VOC concentrations. (c) 2017 Elsevier Ltd. All rights reserved.
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microbiological chemical and sensory Spoilage analysis of raw atlantic cod gadus morhua stored under modified atmospheres
Food Microbiology, 2018Co-Authors: Lotta Kuuliala, Al Y Hage, Angelosgerasimos Ioannidis, Marc Sader, Frederiekmaarten Kerckhof, Mike Vanderroost, Nico Boon, B De Baets, B De MeulenaerAbstract:Abstract During fish Spoilage, microbial metabolism leads to the production of volatile organic compounds (VOCs), characteristic off-odors and eventual consumer rejection. The aim of the present study was to contribute to the development of intelligent packaging technologies by identifying and quantifying VOCs that indicate Spoilage of raw Atlantic cod (Gadus morhua) under atmospheres (%v/v CO2/O2/N2) 60/40/0, 60/5/35 and air. Spoilage was examined by microbiological, chemical and sensory analyses over storage time at 4 or 8 °C. Selected-ion flow-tube mass spectrometry (SIFT-MS) was used for quantifying selected VOCs and amplicon sequencing of the 16S rRNA gene was used for the characterization of the cod microbiota. OTUs classified within the Photobacterium genus increased in relative abundance over time under all storage conditions, suggesting that Photobacterium contributed to Spoilage and VOC production. The onset of exponential VOC concentration increase and sensory rejection occurred at high total plate counts (7–7.5 log). Monitoring of early Spoilage thus calls for sensitivity for low VOC concentrations.
Hans Henrik Huss - One of the best experts on this subject based on the ideXlab platform.
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the effect of biogenic amine production by single bacterial cultures and metabiosis on cold smoked salmon
Journal of Applied Microbiology, 2000Co-Authors: Lasse Vigel Jorgensen, Hans Henrik Huss, Paw DalgaardAbstract:Aim: Biogenic amines are important indicators of Spoilage in vacuum-packed cold-smoked salmon. It is the aim of this study to identify bacteria responsible for biogenic amine production in cold-smoked salmon. Methods and Results: The present study identified Spoilage microflora from cold-smoked salmon and determined biogenic amine production of single and co-cultures growing in cold-smoked salmon. Photobacterium phosphoreum was the only species that produced histamine when inoculated on sterile cold-smoked salmon. Production of putrescine was enhanced 10–15 times when cultures of Serratia liquefaciens or Hafnia alvei were grown with Carnobacterium divergens or Lactobacillus sakei subsp. carnosus. This phenomenon was explained by interspecies microbial metabolism of arginine, i.e., metabiosis. Conclusions: The amounts of biogenic amines produced by single and co-cultures corresponded to those observed during Spoilage of naturally-contaminated cold-smoked salmon. Photobacterium phosphoreum and Lact. curvatus were identified as the specific Spoilage organisms in cold-smoked salmon. Significance and Impact of the Study: Determination of the specific Spoilage organism is needed before a model can be developed for shelf-life predictions of cold-smoked salmon.
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multiple compound quality index for cold smoked salmon salmo salar developed by multivariate regression of biogenic amines and ph
Journal of Agricultural and Food Chemistry, 2000Co-Authors: Lasse Vigel Jorgensen, Paw Dalgaard, Hans Henrik HussAbstract:Production of biogenic amines during chill storage of 12 lots of cold-smoked salmon was studied. These data allowed for a multiple compound quality index to be developed by multivariate regression (partial least square regression). The quality index was based on concentrations of cadaverine, histamine, putrescine, and tyramine and pH and showed good correlation with sensory assessments. Biogenic amines were indicators of Spoilage rather than casual agents of Spoilage off-flavors. Four different biogenic amine profiles were found at the time of Spoilage in cold-smoked salmon. These were the results of differences in the Spoilage microflora. Histamine was detected above regulatory limits but below toxic levels. Measurements of salt and dry matter for calculation of water phase salt could be substituted by rapid water activity measurements. Keywords: Agmatine; cadaverine; putrescine; histamine; tyramine; partial least squares regression; Spoilage; water activity
Koji Suzuki - One of the best experts on this subject based on the ideXlab platform.
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investigation of beer Spoilage ability of dekkera brettanomyces yeasts and development of multiplex pcr method for beer Spoilage yeasts
Journal of The Institute of Brewing, 2015Co-Authors: Satoshi Shimotsu, Koji Suzuki, Shizuka Asano, Kazumaru Iijima, Hiromi Yamagishi, Masayuki AizawaAbstract:There have been many beer-Spoilage incidents caused by wild yeasts. Saccharomyces cerevisiae, Dekkera anomala and D. bruxellensis have been recognized as beer-Spoilage yeasts in the brewing industry. In contrast, the beer Spoilage ability of Brettanomyces custersianus has not been well characterized, although this species was isolated from beer. In this study, the beer-Spoilage ability of currently described Dekkera/Brettanomyces yeast species was investigated. As a consequence, D. anomala, D. bruxellensis and B. custersianus were shown to grow in commercial beers. On the other hand, the remaining two Brettanomyces species, B. naardenensis and B. nanus, did not grow in beer. These results indicate that B. custersianus should be recognized as a beer-Spoilage species, in addition to S. cerevisiae, D. anomala, and D. bruxellensis. Therefore we developed multiplex polymerase chain reaction (PCR) for the simultaneous detection and identification of B. custersianus and the other beer-Spoilage yeast species. For this purpose, PCR primers were designed in the internal transcribed spacer region or 26S rDNA, and each PCR product was made in different sizes to easily discriminate the species from electrophoretic results. Specificity, reactivity and sensitivity of the designed primers were evaluated. As a result, the developed multiplex PCR method was shown to have high specificity and reactivity, and therefore was considered as an effective tool to identify beer-Spoilage yeast species. This tool can contribute to microbiological quality assurance in breweries. Copyright © 2015 The Institute of Brewing & Distilling
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125th anniversary review microbiological instability of beer caused by Spoilage bacteria
Journal of The Institute of Brewing, 2011Co-Authors: Koji SuzukiAbstract:Beer has been generally recognized as a microbiologically stable beverage. However, microbiological incidents occasionally occur in the brewing industry. The microbiological instability of beer is often caused by bacteria consisting of four genera, Lactobacillus, Pediococcus, Pectinatus and Megasphaera. Lactobacillus and Pediococcus belong to the lactic acid bacteria (LAB), whereas Pectinatus and Megasphaera form a group of strict anaerobes that are known as intermediates between Gram-positive and Gram-negative bacteria. The frequencies of beer Spoilage incidents caused by these four genera have been reported to exceed 90% in Europe and therefore Lactobacillus, Pediococcus, Pectinatus and Megasphaera are considered to be the principal Spoilage agents in the brewing industry. Thus, this review consists of three parts involving these four genera. The first part describes Spoilage LAB in alcoholic beverages with some emphasis on beer Spoilage LAB. In this part, the emergence and evolution of these Spoilage LAB is discussed, the insight of which is useful for developing quality control methods for these beverages. The second part is devoted to the hop resistance in beer Spoilage LAB. This area of research is evolving rapidly and recent progress in this field is summarized. The third part concerns Pectinatus and Megasphaera. Although this group of beer Spoilage bacteria has been described relatively recently, the incident reports in Europe increased in the early 1990s, reaching around 30% of Spoilage incidents. Various aspects of Pectinatus and Megasphaera, ranging from their taxonomy and beer Spoilage ability to detection and eradication methods are described.
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rapid detection and identification of beer Spoilage lactic acid bacteria by microcolony method
Journal of Bioscience and Bioengineering, 2009Co-Authors: Shizuka Asano, Koji Suzuki, Kazumaru Iijima, Yasuo Motoyama, Tomoo Ogata, Y KitagawaAbstract:We evaluated a microcolony method for the detection and identification of beer-Spoilage lactic acid bacteria (LAB). In this approach, bacterial cells were trapped on a polycarbonate membrane filter and cultured on ABD medium, a medium that allows highly specific detection of beer-Spoilage LAB strains. After short-time incubation, viable cells forming microcolonies were stained with carboxyfluorescein diacetate (CFDA) and counted with μFinder Inspection System. In our study, we first investigated the growth behavior of various beer-Spoilage LAB by traditional culture method, and Lactobacillus lindneri and several L. paracollinoides strains were selected as slow growers on ABD medium. Then the detection speeds were evaluated by microcolony method, using these slowly growing strains. As a result, all of the slowly growing beer-Spoilage LAB strains were detected within 3 days of incubation. The specificity of this method was found to be exceptionally high and even discriminated intra-species differences in beer-Spoilage ability of LAB strains upon detection. These results indicate that our microcolony approach allows rapid and specific detection of beer-Spoilage LAB strains with inexpensive CFDA staining. For further confirmation of species status of detected strains, subsequent treatment with species-specific fluorescence in situ hybridization (FISH) probes was shown as effective for identifying the CFDA-detected microcolonies to the species level. In addition, no false-positive results arising from noise signals were recognized for CFDA staining and FISH methods. Taken together, the developed microcolony method was demonstrated as a rapid and highly specific countermeasure against beer-Spoilage LAB, and compared favorably with the conventional culture methods.
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development of detection medium for hard to culture beer Spoilage lactic acid bacteria
Journal of Applied Microbiology, 2008Co-Authors: Koji Suzuki, Shizuka Asano, Kazumaru Iijima, Hidetoshi Kuriyama, Y KitagawaAbstract:AIMS: To develop a detection medium for hard-to-culture beer-Spoilage lactic acid bacteria (LAB). METHODS AND RESULTS: Four hard-to-culture beer-Spoilage strains of LAB, belonging to Lactobacillus paracollinoides and Lactobacillus lindneri, have been obtained by repeatedly subculturing the wild-type strains in beer. To develop a countermeasure against these hard-to-culture beer-Spoilage LAB, a beer-based medium was modified. As a consequence, the supplementation of a small amount of de Man Rogosa Sharpe medium was found to enhance the growth of hard-to-culture beer-Spoilage LAB strains obtained in this study. In addition, sodium acetate was shown to improve the selectivity of this beer-based medium. Further comparative study was performed with five other media widely used for the detection of beer-Spoilage LAB in the brewing industry. This study revealed that the newly developed medium, designated advanced beer-spoiler detection (ABD) medium, possessed superior sensitivity for hard-to-culture beer-Spoilage LAB and comparable sensitivity with easy-to-culture beer-Spoilage LAB. Moreover, ABD medium was found to suppress the growth of nonSpoilage micro-organisms, and thereby allow the selective growth of beer-Spoilage LAB. CONCLUSIONS: Advanced beer-spoiler detection medium is considered as an effective tool for comprehensive detection of beer-Spoilage LAB in breweries. SIGNIFICANCE AND IMPACT OF THE STUDY: The detection by ABD medium can be used as an indicator for differentiating the beer-Spoilage ability of LAB without further confirmatory tests in breweries.
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a review of hop resistance in beer Spoilage lactic acid bacteria
Journal of The Institute of Brewing, 2006Co-Authors: Koji Suzuki, Kazumaru Iijima, Kanta Sakamoto, Manabu Sami, Hiroshi YamashitaAbstract:Hop bitter acids play a major role in enhancing the microbiological stability of beer. However, beer Spoilage lactic acid bacteria (LAB) are able to grow in beer by exhibiting strong hop resistance. Recently two hop resistance genes, horA and horC, have been identified in beer Spoilage Lactobacillus brevis ABBC45. The horA gene was shown to encode an ATP dependent multidrug transporter that extrudes hop bitter acids out of bacterial cells. In contrast, the product of the horC gene confers hop resistance by presumably acting as a proton motive force (PMF)-dependent multidrug transporter. Strikingly, the homologs of horA and horC genes were found to be widely and almost exclusively distributed in various species of beer Spoilage LAB strains, indicating these two hop resistance genes are excellent species-independent genetic markers for differentiating the beer Spoilage ability of LAB. Furthermore the nucleotide sequence analysis of horA and horC homologs revealed that both genes are essentially identical among distinct beer Spoilage species, indicating horA and horC have been acquired by beer Spoilage LAB through horizontal gene transfer. Taken collectively, these insights provide a basis for applying horA and horC to the species-independent determination of beer Spoilage LAB, including yet uncharacterized species. In addition to the hop resistance mechanisms mediated by multidrug transporters, proton translocating ATPase and the ATP production system were shown to contribute to the hop resistance mechanisms in beer Spoilage LAB by generating PMF and ATP that are necessary for survival in beer.
