Study of the quality characteristics in cold-smoked salmon (Salmo salar) originating from pre- or post-rigor raw material

Improved slaughtering procedures in the salmon industry have caused a delayed onset of rigor mortis and, thus, a potential for pre-rigor secondary processing. The aim of this study was to investigate the effect of rigor status at time of processing on quality traits color, texture, sensory, microbiological, in injection salted, and cold-smoked Atlantic salmon (Salmo salar). Injection of pre-rigor fillets caused a significant (P<0.001) contraction (-7.9%± 0.9%) on the caudal-cranial axis. No significant differences in instrumental color (a*, b*, C*, or h*), texture (hardness), or sensory traits (aroma, color, taste, and texture) were observed between pre- or post-rigor processed fillets; however, post-rigor (1477 ± 38 g) fillets had a significant (P>0.05) higher fracturability than pre-rigor fillets (1369 ± 71 g). Pre-rigor fillets were significantly (P<0.01) lighter, L*, (39.7 ± 1.0) than post-rigor fillets (37.8 ± 0.8) and had significantly lower (P<0.05) aerobic plate count (APC), 1.4 ± 0.4 log CFU/g against 2.6 ± 0.6 log CFU/g, and psychrotrophic count (PC), 2.1 ± 0.2 log CFU/g against 3.0 ± 0.5 log CFU/g, than post-rigor processed fillets. This study showed that similar quality characteristics can be obtained in cold-smoked products processed either pre- or post-rigor when using suitable injection salting protocols and smoking techniques.

First processing steps and the quality of wild and farmed fish

First processing steps of fish are species-dependent and have common practices for wild and for farmed fish. Fish farming does, however, have certain advantages over traditional fisheries in that the processor can influence postmortem biochemistry and various quality parameters. This review summarizes information about the primary processing of fish based on the influence of catching, slaughtering, bleeding, gutting, washing, and filleting. Recommendations are given for the correct primary processing of fish.