Quality of raw and smoked fillets from clinically healthy Atlantic salmon, Salmo salar L., following an outbreak of pancreas disease (PD) T Taksdal 1 , J Wiik-Nielsen 1 , S Birkeland 2 , P Dalgaard 3 and T Mørkøre 4 1 Norwegian Veterinary Institute, Oslo, Norway 2 Nofima AS, Stavanger, Norway 3 National Food Institute, Technical University of Denmark, Lyngby, Denmark 4 Nofima AS, A ˚ s, Norway Abstract Pancreas disease (PD) is a viral disease of farmed salmonid fish, which causes huge economic losses. Pathological changes in skeletal muscle, pancreas and heart are hallmarks of PD. Stakeholders in the fish-smoking industry have claimed that fillets from PD-affected Atlantic salmon, Salmo salar L., are of poor quality. We therefore examined har- vest-ready, clinically healthy Atlantic salmon from a population of fish previously affected by PD. Histopathological changes in skeletal muscle tis- sues ranged from minor to severe. Fillet quality measurements showed that fish with severe skeletal muscle changes provided a paler raw fillet and a yellowish and harder cold-smoked fillet than nor- mal. PD had no significant effect on fillet gaping, bacteriological quality or off-odour development during storage. An unexpected finding was a sig- nificant subendocardial fibrosis in 23% of the PD-affected fish. The latter may indicate suscepti- bility to stress-related heart failure. Keywords: fillet, colour, texture, smoked salmon, myocarditis, fibrosis. Introduction Pancreas disease (PD) is a viral disease of salmo- nid fish in European aquaculture, caused by salmonid alphavirus (SAV) (Weston et al. 1999). In Norway, PD is endemic in sea water along the west coast, south of latitude 63° (Hustadvika). Economic losses to the Norwegian farming indus- try because of PD were, in 2008, estimated to be 125 million Euro (Torrisen 2008). These losses were mainly attributed to mortality and increased production costs, but were also related to the fact that fish from PD-affected sites are channelled away from special market segments, such as smoked salmon, because of expected poor fillet quality (Aunsmo et al. 2010). Stakeholders from the fish-smoking industry have claimed that fillets of salmon from such fish groups are of poor qual- ity, with a higher degree of melanization, acceler- ated bacterial spoilage and shorter shelf-life compared with unaffected fish. This has recently been evaluated in two studies, in which harvested fish of different sizes and condition factors were included. Lerfall et al. (2012) attributed deviations in several fillet quality parameters in raw and smoked fillets to PD and found that the degree of change was influenced by the time between PD outbreak and harvest. Larsson et al. (2012) identi- fied unacceptable fillet quality in fish with very low condition factor from a PD-affected farm. However, studies relating to analysis of fillets obtained exclusively from fish in good condition and with a normal body shape regarded as superior at the market have not been published. While the pancreas is the primary organ affected by PD, severe cardiac and skeletal myopathies are also key features of this disease (Taksdal et al. 2007). Knowledge relating to the morphological status of these organs in clinically Correspondence T Taksdal, Norwegian Veterinary Institute, PO Box 750 Sentrum, NO-0106 Oslo, Norway (e-mail: torunn.taksdal@vetinst.no) 1 Ó 2012 Blackwell Publishing Ltd Journal of Fish Diseases 2012 doi:10.1111/j.1365-2761.2012.01428.x