Food safety of salt-cured cod products : effects of salt-curing, rehydration and thermal treatmenton survival, growth and invasiveness of Listeria spp.

• Main Author: Lorentzen, Grete
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: Universitetet i Tromsø 2010
• Subjects: VDP::Teknologi: 500::Næringsmiddelteknologi: 600; VDP::Matematikk og naturvitenskap: 400::Basale biofag: 470::Generell mikrobiologi: 472; Mennen; Mikkelsen; Ytterstad; Gadus morhua
• Online Access: https://hdl.handle.net/10037/2911

The papers of the thesis are not available in Munin: 1. Lorentzen, G., Olsen, R. L., Bjørkevoll, I., Mikkelsen, H. & Skjerdal, O.T.: 'Survival of Listeria monocytogenes in muscle of cod ( Gadus morhua L.) during saltcuring and growth during chilled storage of rehydrated product', Food Control, Volume 21, Issue 3, March 2010, Pages 292-297 (Elsevier - publisher's restrictions). Available at http://dx.doi.org/10.1016/j.foodcont.2009.06.012 2. Lorentzen, G., Ytterstad, E., Olsen, R.L. & Skjerdal, O.T.: 'Thermal inactivation and growth potential of Listeria innocua in rehydrated salt-cured cod prepared for ready-to-eat products', Food Control, Volume 21, Issue 8, August 2010, Pages 1121-1126 (Elsevier - publisher's restrictions). Available at http://dx.doi.org/10.1016/j.foodcont.2010.01.006 3. Lorentzen, G., Mennen, S., Olsen, R.L. & Skjerdal, O.T.: 'Invasiveness of Listeria monocytogenes strains of Caco-2 cells in response to a period of extreme salt stress reflecting salt-curing and rehydration of cod ( Gadus morhua L.)', accepted manuscript, later published as Food Control, Volume 22, Issue 7, July 2011, Pages 1040-1045, available at http://dx.doi.org/10.1016/j.foodcont.2010.12.013 Salt-cured and dried salt-cured (klipfish) cod (Gadus morhua L.) are highly appreciated. Salt fish and klipfish are mainly prepared by rehydration to lower the level of salt. The rehydrated cod can be used in several dishes and consumption of these products has been considered safe due to the high level of salt. The overall aim of the thesis was to study the food safety of salt-cured fish products using Listeria spp. as an indicator. Initially, we studied the survival of Listeria spp. in muscle of cod during salt-curing and growth during chilled storage of the rehydrated product. These experiments demonstrated that long term exposure to high salt concentrations did not eliminate Listeria spp., and that Listeria spp. being present in the fish prior to salt-curing could recover and grow in rehydrated salt-cured cod during ...