SEA 



SCIENCE 



TOP: A Hanover Sea Products employee 

 prepares some fish fillets on a table 

 that was sanitized with ozone. 

 BOTTOM: Ozone can be used as a 

 broad-use sanitizing agent. 



-lor many years, scientists have known 

 that ozone high in the atmosphere protects 

 humans from the harmful ultraviolet rays of the 

 sun. 



But the powerful oxidant could have 

 another benefit on earth — enhancing the 

 freshness of raw seafood. 



Recently, scientists from the North 

 Carolina State University Seafood Laboratory in 

 Morehead City discovered that ozone reduced 

 the population of common spoilage bacteria in 

 seafood processing facilities. The researchers 

 worked with Peter Mairs of Hanover Sea 

 Products in Wilmington. 



The study, funded by the N.C. Fishery 

 Resource Grant Program (FRG), found that 

 treating raw fish and processing equipment with 

 ozone greatly reduced the number of bacteria 

 that could potentially spoil seafood, according to 

 Barry Nash, North Carolina Sea Grant seafood 

 technology and marketing specialist. The FRG 

 program, funded by the N.C. General Assembly 

 and administered by North Carolina Sea Grant, 

 supports projects for seafood processors and 

 others in the seafood and fishing industries. 



Ozone also enhanced the freshness of raw 

 fish during refrigerated storage, according to 

 study results. 



"We demonstrated the potential effective- 

 ness of ozone as a broad-use, sanitizing agent in 

 a seafood production facility," says Nash. 



'This is important because bacteria are 

 everywhere in the environment. However, the 

 use of ozone could greatly reduce the number of 

 spoilage bacteria in a seafood plant and help 

 maintain low levels of spoilage bacteria over 

 time in air, water and on processing equipment," 

 he adds. 



Researchers also found that ozone seemed 

 to improve the shelf life of uncooked fish. 



"Ozone extended the shelf life of our 

 treated fish by one or two days," says Barbara 

 Blakistone, one of the project's investigators and 

 a packaging consultant. "That is important when 

 dealing with fresh fish. Ozone could help 

 enhance product quality and lengthen the shelf 

 life of fish so that seafood lasts longer in the 

 retail or wholesale distribution chain." 



What's more, ozone did not alter the 

 appearance, color or aroma of the fresh fish, says 

 Nash. "So the sensory characteristics of the 

 treated fish were not affected." 



There were other benefits from treating air 

 and water with ozone at the Wilmington seafood 

 processing facility, where the research was 

 conducted. 



"Ozone is immediately lethal to bacteria," 

 says Nash. "Our qualitative results showed that 

 ozone caused a marked and sustained decrease 

 in air- and water-borne bacteria. This has 

 important implications for minimizing bacterial 

 cross-contamination in the workplace environ- 

 ment. 



"If the population of spoilage bacteria in a 

 plant can be quickly reduced and maintained at 

 low levels on both seafood and processing 

 equipment, the ultimate benefit to processors 

 could be an extension in shelf life for a highly 

 perishable food product such as fresh fish." 



Other Advantages 



Robb Mairs, general manager of Hanover 

 Sea Products, finds the results promising for 

 seafood dealers. 



By extending the shelf life, seafood dealers 

 can reduce the amount of fish they lose to 

 normal spoilage, says Mairs. 'This will result in 

 increased profitability in the seafood processing 

 industry." 



Produced when air or oxygen is passed 

 through an electric spark, ozone is found in 

 minute quantities in the atmosphere. Following a 

 thunderstorm, it creates the fresh, clean smell in 

 the air. 



For the study, researchers set up an ozone 

 generator that produced and dissolved ozone 

 into the water. The whole fish were soaked in 

 treated water and then filleted and vacuum 

 packaged. 



The fillets were refrigerated at 41 degrees F 

 for 12 days to monitor the growth of spoilage 

 bacteria. To observe ozone's effect on bacteria 

 on food contact surfaces, researchers also treated 

 knives, cutting tables and employee gloves and 

 aprons. 



"Ozone is not meant as a replacement for 



24 EARLY SUMMER 2002 



