CO2-equivalent emissions and quality evaluation of chilled and frozen Atlantic salmon transported from Norway to Japan

Atlantic salmon (Salmo salar) is the top imported fish in Japan. It is usually shipped in chilled form by air cargo to preserve its freshness but posts a high environmental impact. As a sustainable alternative, ocean freight can be implemented if the salmon is frozen. However, the question arises as to whether the quality of the frozen and thawed salmon is comparable. Therefore, the aim of this study is to evaluate the environmental impact and quality of Norwegian Atlantic salmon in chilled and frozen form. The CO₂ equivalent emissions of the key life-cycle stages were calculated, and the quality assessment was carried out by colorimetry and sensory evaluation with careful preparation and execution. The results showed that the CO₂ equivalent emissions of the packaging, transport, and overall cycle of the frozen salmon were 35 %, 90 %, and 60 % lower than those of the chilled salmon. Color measurements using digital imaging show that the frozen salmon is slightly redder, with a higher a* value and a lower b* value. Panelist ratings indicated that there was no statistically significant difference in perceived color, glossiness, fishy smell, texture, umami, and juiciness between chilled and frozen salmon. The study provides preliminary results that demonstrate the potential of frozen seafood and ocean freight transportation as a sustainable cold chain solution.