Salmon feeds have changed over the years, leading to changed biochemical composition of the fish. The main aim of this study was to compare biochemical compositions and storage stability of commercially produced organic and conventional salmon. Organically (n = 40) and conventionally farmed salmon (n = 39) were sampled. The fish were anesthetized, killed by gill cutting and bled before filleting. Fish samples were subjected to proximate analysis, fatty acid and amino acid composition, along with colour and TBARS analyses. The lipid content of organically and conventionally farmed salmon was 13% and 17 %, respectively. Organic fish contained approximately 48 % more EPA and DHA than did the conventional fish, 17.2 g kg⁻¹ vs. 11.6 g kg⁻¹, respectively. The organic salmon had lower colour saturation than the conventional, and TBARS were higher in the organic than in the conventional salmon. To conclude, the main differences between fresh organic and conventional salmon were related to lipid content and fatty acid composition. The high energy level in both groups should be considered when making dietary recommendations. Organic salmon is less stable due to its high content of long-chained unsaturated fatty acids, and appears similar to conventionally farmed salmon some years ago.

Fish quality and shelf life can be evaluated using various assessment methods, such as sensory analysis, biochemical tests, microbiological evaluations, and physicochemical analyses. However, these methods are invasive and time-consuming, driving interest in technologies capable of estimating shelf life through non-invasive procedures. This study investigates the potential of hyperspectral imaging as a non-invasive technology for predicting the shelf life of Atlantic cod. A storage experiment was conducted that included both gutted fish with heads (GFWH) and fillets, with sensory evaluation and biochemical measurements employed to determine shelf life. Subsequently, hyperspectral images of the fish samples were captured under industrial production conditions, and the spectral data were analyzed using different regression algorithms. The majority of the regression techniques utilized in this research successfully predicted shelf life for both fillets and GFWH, achieving a root mean square error (RMSE) lower than one day. While most regression models exhibited comparable performance in predicting the shelf life of fillets, deep learningbased models demonstrated superior performance for GFWH. These results suggest that hyperspectral imaging technology has significant potential as a non-invasive tool for estimating the shelf life of Atlantic cod, thereby enabling effective quality-based sorting, reducing food waste, and enhancing sustainability in the seafood supply chain.

Fresh Atlantic cod is available in large amounts in Norway during the first 5 months of the year. Live-storage of cod may extend the marketing period of fresh cod products throughout the year. In addition, this concept makes pre-rigor processing possible. The main problem of keeping wild cod in captivity is that it does not easily accept formulated dry feed. The purpose of this study was, therefore, to investigate how long-term live-storage of mature Atlantic cod in the absence of feed (79 days) affects the onset and development of rigor mortis, as well as fillet quality by assessing hardness and water-holding capacity of the muscle, pH, protein, and water content. The results showed that starvation of Atlantic cod for 23 days reduces the pre-rigor time from 29 to 17 h. Further starvation did not decrease this period significantly, suggesting that live-stored cod deprived of feed for 79 days may still be industrially processed before the onset of rigor mortis. More than 51 days of starvation reduced protein concentration and increased water content of the muscle. After 51 days, the muscle texture was softer than in fish starved for a shorter period.