Refrigerated seawater depuration for reducing Vibrio parahaemolyticus contamination in pacific oyster (Crassostrea gigas).
The efficacy of refrigerated-seawater depuration for reducing Vibrio parahaemolyticus levels in Pacific oyster (Crassostrea gigas) was investigated. Raw Pacific oysters were inoculated with a mixed culture of five clinical strains of V. parahaemolyticus (10(5) to 10(6) most probable number [MPN] per g) and depurated with refrigerated seawater (5 degrees C) in a laboratory-scale recirculation system equipped with a 15-W gamma UV sterilizer. Depuration with refrigerated seawater for 96 h reduced V. parahaemolyticus populations by >3.0 log MPN/g in oysters harvested in the winter. However, 144 h of depuration at 5 degrees C was required to achieve a 3-log reduction in oysters harvested in the summer. Depuration with refrigerated seawater at 5 degrees C for up to 144 h caused no significant fatality in the Pacific oyster and could be applied as a postharvest treatment to reduce V. parahaemolyticus contamination in Pacific oysters. Further studies are needed to validate the efficacy of the depuration process for reducing naturally accumulated V. parahaemolyticus in oysters.
Seafood Research and Education Center, Oregon State University, Astoria, Oregon 97103, USA. yi-cheng.su@oregonstate.edu
Yi-Cheng
YC
Su
Qianru
Q
Yang
Claudia
C
Häse
D000818:Animals; D003257:Consumer Product Safety; D049896:Crassostrea / Q000382:microbiology*; D005506:Food Contamination / Q000032:analysis / Q000517:prevention & control; D005519:Food Preservation / Q000379:methods*; D006801:Humans; D012034:Refrigeration; D012758:Shellfish / Q000382:microbiology*; D014736:Vibrio parahaemolyticus / Q000254:growth & development*