Sub-chilling methods for Atlantic salmon with 7 days in refrigerated seawater and subsequent sub-chilled storage

This study evaluated the sub-chilling of whole gutted Atlantic salmon in refrigerated seawater (RSW) maintained at -1 °C for 7 days, compared to traditional ice storage at 0 °C and RSW storage at -1 °C for 4 days followed by 3 days without ice. After filleting, portioning, and modified atmosphere packaging, the initial RSW-stored fish were continuously stored at -1 °C, while the initial ice-stored fish were stored at refrigerated temperatures at 4 °C. The 7-day RSW storage resulted in a significant weight gain, higher water-holding capacity (WHC), and increased water and salt content. Ice-stored fish had higher calpain activity. After packaging, drip loss was highest for the 4-day RSW-stored fish. The 7-day RSW-stored fish demonstrated consistently better WHC and water content. The CO₂ levels decreased, while O₂ levels increased more rapidly within the package for the RSW-stored fish. There was also a significant extension in the microbiological and sensory shelf life for the RSW-stored fish. Photobacterium was the dominant bacterium in all storage methods. This study highlights the potential to extend salmon shelf life with sub-chilling, significantly reducing ice usage.