2.5.1. Application of ozone in seafood processing

2.5.1. Application of ozone in seafood processing

Pathogenic bacteria and viruses present in fish are highly sensitive to residual ozone in water. 99.9% or higher inactivation of Aeromonas spp., Vibrio anguillarum and Yersinia ruckeri is obtained at residual ozone concentrations of 0.15 – 0.20 mg / l within 60 seconds in natural lake, brackish and sea water. In fish farm effluent, a residual concentration of 0.3-0.4 mg/l is required for Aeromonas inactivation. Among fish pathogenic viruses, high sensitivity toward ozone has generally been reported. This also applies to viruses with high UV resistance, i.e. IPNV and WSBV as reported by many researchers.

 Because of its instability, ozone must be generated and used on-site. The most efficient method is by the electric discharge technique, which involves the passage of oxygen gas, or air, across the gap of narrowly spaced electrodes under high voltage. Due to the energy costs of producing ozone, it is important to optimize the transfer efficiency from gas to liquid phase. 

Ozone in seafood processing and fisheries

 The method of use of ozone started in late 1996 onboard purse - seiners with an idea to decrease bacteriological problems in the circulation of RSW system.

Today, ozone is used in the seafood processing and fishery industry in areas such as:

  • Purse-seiners – seawater is ozonised and circulated through RSW tanks and circulation systems so that it comes in contact with every surface and carries out clearing.
  • Well boats – when transporting live fish you have to obtain a high level of hygiene in order to prevent mortality by pathogens. By using Ozonised Sea water to reduce contaminants from tanks and circulation systems, and disinfects them in accordance with applicable requirements.
  • Processing plants – ozonised sea/fresh water is used for cleaning and disinfection of process area, equipment and pipelines.
  • Inlet water for fish hatcheries
  • Waste water treatment – effluent from aquaculture, fish processing and fish slaughtering. The waste water treatment systems must be tailor-made according to regulations and are based on a combination of methods such as filtration, flotation and separation, and ozonisation.
  • Odour-ozone has been successfully used in several applications to treat odour from fish or waste storage.
     
Last modified: Sunday, 25 December 2011, 10:18 AM