Refrigerated seawater depuration for reducing Vibrio parahaemolyticus contamination in raw Pacific oysters (Crassostrea gigas)
Vibrio parahaemolyticus is a seafood-borne pathogen that can cause gastroenteritis in humans. This study investigated the effectiveness of refrigerated seawater (5°C) depuration on reducing V. parahaemolyticus in raw Pacific oysters (Crassostrea gigas). Raw Pacific oysters were inoculated with a mix...
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ftoregonstate:ir.library.oregonstate.edu:8p58ph22v 2024-09-15T18:03:13+00:00 Refrigerated seawater depuration for reducing Vibrio parahaemolyticus contamination in raw Pacific oysters (Crassostrea gigas) Yang, Qianru Su, Yi-cheng Morrissey, Michael T. Daeschel, Mark A. Harding, Anna K. Food Science and Technology Oregon State University. Graduate School https://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/8p58ph22v English [eng] eng unknown Oregon State University https://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/8p58ph22v All rights reserved Seafood -- Contamination -- Prevention Pacific oyster -- Processing Pacific oyster -- Microbiology Pacific oyster -- Effect of temperature on Vibrio parahaemolyticus Pacific oyster -- Sanitation Masters Thesis ftoregonstate 2024-07-22T18:06:03Z Vibrio parahaemolyticus is a seafood-borne pathogen that can cause gastroenteritis in humans. This study investigated the effectiveness of refrigerated seawater (5°C) depuration on reducing V. parahaemolyticus in raw Pacific oysters (Crassostrea gigas). Raw Pacific oysters were inoculated with a mixed culture of five clinical strains of V. parahaemolyticus and depurated with cold seawater (5°C) in a pilot scale recirculating system. The refrigerated seawater depuration was more efficient in reducing V. parahaemolyticus contamination in oysters harvested in winter than in summer. Populations of V. parahaemolyticus in oysters harvested in winter were reduced by >1.2 log MPN/g after 24 h of depuration in refrigerated seawater. Reductions of V. parahaemolyticus in the oysters increased to about 2.3 log MPN/g after 48 h and reached 3.1 log after 96 h of the process. However, it required 144 h of depuration in the refrigerated seawater to achieve a 3-log (MPN/g) reduction of V. parahaemolyticus in oysters harvested in summer. The efficacies of refrigerated seawater depuration in reducing V. parahaemolyticus were determined at a rate of 0.0211-log/h in oysters harvested in the summer and 0.0362-log/h in oysters harvested in the winter. This is probably due to the differences between water temperatures of the oyster harvest site (7-9ºC in winter, 16-17ºC in summer) and the refrigerated seawater (5ºC). Because of the increased temperature difference in the summer, it would require a longer time for oysters to adjust their biological activity to the new environment. Depuration of raw oysters in recirculated refrigerated seawater (5ºC) for up to 144 h did not cause a noticeable fatality of oysters, but increased their ability to survive in subsequent cold storage. The process also reduced fecal coliform contamination in oysters from 10³ MPN/g to less than 20 MPN/g. When oysters were stored in a refrigerator, 90% of oysters with or without depuration treatment survived after 7 days. However, the survival rate of oysters ... Master Thesis Crassostrea gigas Pacific oyster ScholarsArchive@OSU (Oregon State University) |
institution |
Open Polar |
collection |
ScholarsArchive@OSU (Oregon State University) |
op_collection_id |
ftoregonstate |
language |
English unknown |
topic |
Seafood -- Contamination -- Prevention Pacific oyster -- Processing Pacific oyster -- Microbiology Pacific oyster -- Effect of temperature on Vibrio parahaemolyticus Pacific oyster -- Sanitation |
spellingShingle |
Seafood -- Contamination -- Prevention Pacific oyster -- Processing Pacific oyster -- Microbiology Pacific oyster -- Effect of temperature on Vibrio parahaemolyticus Pacific oyster -- Sanitation Yang, Qianru Refrigerated seawater depuration for reducing Vibrio parahaemolyticus contamination in raw Pacific oysters (Crassostrea gigas) |
topic_facet |
Seafood -- Contamination -- Prevention Pacific oyster -- Processing Pacific oyster -- Microbiology Pacific oyster -- Effect of temperature on Vibrio parahaemolyticus Pacific oyster -- Sanitation |
description |
Vibrio parahaemolyticus is a seafood-borne pathogen that can cause gastroenteritis in humans. This study investigated the effectiveness of refrigerated seawater (5°C) depuration on reducing V. parahaemolyticus in raw Pacific oysters (Crassostrea gigas). Raw Pacific oysters were inoculated with a mixed culture of five clinical strains of V. parahaemolyticus and depurated with cold seawater (5°C) in a pilot scale recirculating system. The refrigerated seawater depuration was more efficient in reducing V. parahaemolyticus contamination in oysters harvested in winter than in summer. Populations of V. parahaemolyticus in oysters harvested in winter were reduced by >1.2 log MPN/g after 24 h of depuration in refrigerated seawater. Reductions of V. parahaemolyticus in the oysters increased to about 2.3 log MPN/g after 48 h and reached 3.1 log after 96 h of the process. However, it required 144 h of depuration in the refrigerated seawater to achieve a 3-log (MPN/g) reduction of V. parahaemolyticus in oysters harvested in summer. The efficacies of refrigerated seawater depuration in reducing V. parahaemolyticus were determined at a rate of 0.0211-log/h in oysters harvested in the summer and 0.0362-log/h in oysters harvested in the winter. This is probably due to the differences between water temperatures of the oyster harvest site (7-9ºC in winter, 16-17ºC in summer) and the refrigerated seawater (5ºC). Because of the increased temperature difference in the summer, it would require a longer time for oysters to adjust their biological activity to the new environment. Depuration of raw oysters in recirculated refrigerated seawater (5ºC) for up to 144 h did not cause a noticeable fatality of oysters, but increased their ability to survive in subsequent cold storage. The process also reduced fecal coliform contamination in oysters from 10³ MPN/g to less than 20 MPN/g. When oysters were stored in a refrigerator, 90% of oysters with or without depuration treatment survived after 7 days. However, the survival rate of oysters ... |
author2 |
Su, Yi-cheng Morrissey, Michael T. Daeschel, Mark A. Harding, Anna K. Food Science and Technology Oregon State University. Graduate School |
format |
Master Thesis |
author |
Yang, Qianru |
author_facet |
Yang, Qianru |
author_sort |
Yang, Qianru |
title |
Refrigerated seawater depuration for reducing Vibrio parahaemolyticus contamination in raw Pacific oysters (Crassostrea gigas) |
title_short |
Refrigerated seawater depuration for reducing Vibrio parahaemolyticus contamination in raw Pacific oysters (Crassostrea gigas) |
title_full |
Refrigerated seawater depuration for reducing Vibrio parahaemolyticus contamination in raw Pacific oysters (Crassostrea gigas) |
title_fullStr |
Refrigerated seawater depuration for reducing Vibrio parahaemolyticus contamination in raw Pacific oysters (Crassostrea gigas) |
title_full_unstemmed |
Refrigerated seawater depuration for reducing Vibrio parahaemolyticus contamination in raw Pacific oysters (Crassostrea gigas) |
title_sort |
refrigerated seawater depuration for reducing vibrio parahaemolyticus contamination in raw pacific oysters (crassostrea gigas) |
publisher |
Oregon State University |
url |
https://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/8p58ph22v |
genre |
Crassostrea gigas Pacific oyster |
genre_facet |
Crassostrea gigas Pacific oyster |
op_relation |
https://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/8p58ph22v |
op_rights |
All rights reserved |
_version_ |
1810440727809753088 |