Down in Pass Christian at Bay St. Louis, Mississippi, as the adjoining waters of the Gulf of Mexico warm, Crystal Seas Seafood is offering its customers something new that the seafood company is calling “Crystal Clear Oysters.” The “live,” in-shell oysters are kept cold from reef to table for a promised reef-fresh flavor. Oh, and they’ve been irradiated to eliminate Vibrio to non-detectable levels and tested for quality assurance. Vibrio are dangerous bacteria that can cause serious foodborne illness in those who eat contaminated shellfish. They are the summer’s bug-a-boo for raw oysters, causing illnesses and harvest area closures. But this summer, Vibrios won’t threaten sales for Crystal Seas Seafood because the Mississippi Gulf company will be using a new $5 million food irradiation facility located at the Gulfport-Biloxi International Airport. The irradiation service is built into a $12 million cargo warehouse at the airport, which has completed a $51 million expansion since Hurricane Katrina. The company that runs the irradiation business, Gateway America, LLC, says it is offering the Gulf oyster industry a way to increase food safety and extend the shelf life of its shellfish. Before the arrival of irradiation at the airport, the Mississippi Department of Marine Resources recognized three post-harvest processing options for oysters. They included:
- Individually Quick Frozen (IQF) – Oysters are frozen to reduce microorganisms including Vibrio bacteria and increase shelf life.
- Heat-Cool Pasteurization (HCP) – Oysters are put through a patented hot-cold pasteurization process, often used for packing for the half shell market.
- High Hydrostatic Pressure (HHP) – Oysters are subjected to a patented high-pressure system that decreases microorganisms including Vibrio, used for both half shell and shucked meat.
The state’s education materials for oystermen does recognize the potential for irradiation, high pulse magnet and value-added product technologies for post harvesting, but that future has arrived at the airport. In a region where aficionados will discuss and debate the taste and texture of raw oysters almost by reef, many will be watching the reaction to the Crystal Clear Oysters. Crystal Seas Seafood can make the claim their oyster will be keep cold until served because irradiation only increases the temperature by about a half degree and it’s then brought back down. That’s far less “heat” applied than other intervention methods. Gateway’s food customers at the new airport facility are not limited to oystermen. It says exotic produce and imports going through the port of entry will have to go through irradiation. Vibrio vulnificus (V. vulnificus) and Vibrio parahaemolyticus (V. parahaemolyticus) are bacteria that occur naturally in warm coastal areas, such as the Gulf of Mexico, and their presence often leads to harvest area closures after raw or undercooked oysters are consumed and make people sick, or after water temperatures are deemed to amenable to the bacteria. V. parahaemolyticus can causes non-bloody diarrhea as soon as 2 to 48 hours after exposure. V. vulnificus infects the bloodstream of immune compromised persons and after a 1 to 7 day incubation period can result in death within two days. Vibrio bacteria occur naturally in the Gulf of Mexico. During warm-water months high concentrations can occur. Early in the Obama Administration, the U.S. Food and Drug Administration (FDA) tried to ban raw oysters during the more dangerous summer months, but reaction from the Gulf caused the federal government to back off the idea—at least for the time being.