Origin and spoilage potential of the microbiota dominating genus Psychrobacter in sterile rehydrated salt-cured and dried salt-cured cod (Gadus morhua)

Influence of cod freshness on the salting, drying and desalting stages

“…The inoculated tubes were incubated at 12°C, and the number of surviving strains was determined after 3 days by plating 100 ll of culture from each of the salt concentrations on Plate Count Agar supplemented with 3% NaCl. The colonies were phenotypically characterized as described by Bjørkevoll, Olsen, and Skjerdal (2003) and internally compared.…”

“…After 6 days of chilled storage, however, Psychrobacter sp represented 95-100% of the total count in all samples, and a musty odor had developed. Psychrobacter sp have been shown to be major spoilage bacteria in desalted cod, causing a musty off-odor being sensory detectable at approximately 10 6 -10 7 cfu/g of fish (Bjørkevoll et al, 2003;Skjerdal et al, 2002). These bacteria are predominant in most fresh cod, but are able to survive as non-growing cells during salting and drying, and recover during desalting (Bjørkevoll et al, 2003).…”

Survival of Listeria innocua and Listeria monocytogenes in muscle of cod (Gadus morhua L.) during salt-curing and growth during chilled storage of rehydrated product

“…are able to survive in cod during salt-curing and to grow during storage of the rehydrated product, particularly at elevated refrigerated temperatures. So, even though chilled rehydrated salt-cured cod products have a short sensory shelf life (Bjørkevoll et al, 2003;Fernández-Segovia, Garrigues, Carot, & Escriche, 2003;Magnússon, Sveinsdóttir, Lauzon, Thorkelsdóttir, & Martinsdóttir, 2006), the present work suggest that there is a possibility that low levels of L. monocytogenes in salt-cured cod may grow to infective levels for sensitive consumers before the rehydrated product is considered sensory unacceptable. The risk that Listeria infected rehydrated salt-cured cod products reach the market could be lowered by improved hygienic routines, increased frequency of analysis of the rehydrated products, and storage below 4°C.…”

“…However, in the case of saltcured cod it has been shown that some bacteria are not eliminated during salt-curing (Barat et al, 2006;Vilhelmsson, Hafsteinsson, & Kristjansson, 1997) and among these are the specific spoilage organism in rehydrated salt-cured cod; Psychrobacter spp. (Bjørkevoll, Olsen, & Skjerdal, 2003). Studies regarding survival of food borne pathogens like Listeria spp.…”

Rehydration of salt-cured cod using injection and tumbling technologies

“…(CFU) on Plate Count Agar (PCA) (Oxoid, Basingstoke, UK) with 3.0% (w/v) NaCl added (Bjørkevoll, Olsen, & Skjerdal, 2003). Plates were analysed after 5 days of incubation at 20°C.…”