89A-13 |
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T. REN and Y.-C. Su. Food Science and Technology, Oregon State University, OSU Seafood Laboratory, 2001 Marine Drive, Room 253, Astoria, OR 97103 The United States produces more than 27 million pounds of oysters each year and most of them are sold and consumed raw without further processing. Growth of naturally contaminating bacteria in oysters during storage and retail sale results in loss of quality, reduced shelf life, and diminished value. The potential contamination of Vibrio parahaemolyticus and Vibrio vulnificus in oysters is also a safety concern of the industry and consumers. This study investigated the application of electrolyzed oxidizing (EO) water processing as a potentially innovative strategy to reduce bacteria contamination and improve shelf life and safety of oysters for consumption. Freshly harvested Pacific oysters (shell stock) were placed in a tank with running EO water containing 2% NaCl. Air was pumped into the tank to help in maintaining the level of dissolved oxygen in the water. Total plate counts and psychrotrophs of the oysters were determined at 0, 2, 6, and 8 hours. EO water exhibited strong bactericidal effects against pure cultures of V. parahaemolyticus and V. vulnificus. Greater than 3-log of reductions of each Vibrio species were observed when a six-strain mixture was suspended in EO water for 30 s. Population of V. vulnificus (6 strains cocktail) in laboratory-contaminated oysters was reduced from 53 MPN/g to non-detectable level (< 3.0 MPN/g) after 12 hr of the process. In addition, total bacterial populations in oysters were reduced by 40% after 8 hr of EO water treatment. These results indicate that EO water might be used as an oyster processing aid to reduce spoilage and pathogenic bacteria in oysters. Further studies are needed to determine the optimal condition of EO water treatment for improving quality and safety of raw oysters for consumption.
Session 89A, Aquatic Food Products: General
2005 IFT Annual Meeting, July 15-20 - New Orleans, Louisiana |