Eating raw oysters is getting safer, thanks to a new practice called post-harvest processing, or PHP, that virtually eliminates harmful Vibrio vulnificus bacteria from the shellfish, say University of Florida researchers.
The technology involved isn’t cheap, so UF experts are helping processors in Apalachicola, heart of Florida’s oyster industry, evaluate various methods and learn to use them successfully, said Victor Garrido, a research coordinator with UF’s Institute of Food and Agricultural Sciences.
For decades, freshly harvested oysters were simply stored under refrigeration to discourage bacterial growth. Three new cold-based methods appear most promising for the Florida industry, Garrido said. One flash-freezes oysters with liquid nitrogen, another does the job with powerful blast freezers, a third uses immersion in hot water, then ice slush, and finishes with a trip to the freezer. All three result in raw, half-shell oysters that are frozen solid and may be stored for several months without loss of quality.
Currently, three Florida oyster processing firms are using or preparing to use PHP. In 2004, Leavins Seafood became the first producer in Florida to offer PHP-treated oysters commercially, using a liquid nitrogen method that owner Grady Leavins developed.