Treatment Options to Eliminate or Control Growth of Listeria monocytogenes on Raw Material and on Finished Product for the Smoked Fish Industry


The Smoked Seafood Working Group (SSWG), a collaboration of the National Fisheries Institute, the National Food Processors Association, several smoked fish processors and universities, reviewed scientific papers that describe possible treatments to eliminate or reduce the amount of Listeria monocytogenes present on incoming raw material and eliminate or minimize its growth on finished product. Suggested treatment options that are approved for use on seafood, can be used by most commercial smoked fish companies, and have potential to significantly reduce L. monocytogenes numbers on incoming raw fish include (1) washing of raw fish with water containing chlorine and (2) treatment of raw fish with calcium hydroxide solution (pH 12). Other potential treatments approved for raw materials include washing of fish with acidified sodium chlorite solutions, ozone treatment, steam surface pasteurization, and electrochemical brine tank treatments. Treatment options to control L. monocytogenes on finished product include (1) freezing of finished product to stop growth; and (2) addition of approved chemical growth inhibitors. Other treatment options that have potential to eliminate L. monocytogenes or control its growth on finished product but that are not currently approved for use on seafood include addition of natural growth inhibitors, addition of high levels of Carnobacterium piscicola (~2 x 106 CFU/g), and irradiation. All treatment options require validation under commercial processing conditions.