No abstract

Salmon slaughtered by standard routines (control) or stressed by confinement for 10 min before stunning and then stored at 0.4 or 3.3ЊC for 9 days were compared. Handling stress led to lower muscle phosphocreatine (pϽ0.001), adenosine-5'-triphosphate (pϽ0.05) and shorter pre-rigor period. Storage temperature affected external quality index, white muscle pH and K-value (degradation products of ATP). Stress produced a softer fillet (pϽ0.001). A lower breaking strength (pϽ0.01) was found in fish stored at 0.4ЊC. Sensory tests distinguished the control/ stress groups within the 0.4ЊC chilling regime and the 0.4ЊC/3.3ЊC chilling groups within the control regime. Stress caused a lower score for texture (pϽ0.05) both at 0.4 and 3.3ЊC and for odor at 3.3ЊC in a descriptive sensory test. No detectable effects of stress or storage temperature were found on flavor or color.

No abstract

The changes in skin and fillet color of anesthetized and exhausted Atlantic salmon were determined immediately after killing, during rigor mortis, and after ice storage for 7 d. Skin color (CIE L*, a*, b*, and related values) was determined by a Minolta Chroma Meter. Roche SalmoFan Lineal and Roche Color Card values were determined by a computer vision method and a sensory panel. Before color assessment, the stress levels of the 2 fish groups were characterized in terms of white muscle parameters (pH, rigor mortis, and core temperature). The results showed that perimortem handling stress initially significantly affected several color parameters of skin and fillets. Significant transient fillet color changes also occurred in the prerigor phase and during the development of rigor mortis. Our results suggested that fillet color was affected by postmortem glycolysis (pH drop, particularly in anesthetized fillets), then by onset and development of rigor mortis. The color change patterns during storage were different for the 2 groups of fish. The computer vision method was considered suitable for automated (online) quality control and grading of salmonid fillets according to color.