Several major market operators argue that the current level of knowledge about quality is too scant to justify a switch to a large-scale production of triploid salmon. The aim of the present study was, therefore, to elucidate how rearing conditions (5, 10 and 15°C) affect the flesh quality of triploid Atlantic salmon (Salmo salar L., 1.6±0.3kg). As a reference, diploid salmon kept under equal conditions and with equal genetics were used. The main design discriminant was the holding temperature; increased temperature gave increased blood lactate, rigor index (Ir), drip loss (DL), content of astaxanthin and intensity of redness, but reduced muscle pH, cathepsin activity and fillet lightness. Salmon kept at 10°C grew the fastest. It is concluded that ploidy gave less variation than temperature. Triploids were characterized by lower blood haematocrit (Hct) and Ir, higher DL and collagenase activity, and on average, paler and less yellowish fillets.

The impact of increased muscle temperature at the point of filleting on fillet quality of raw- and cold-smoked Atlantic salmon was investigated. Commercially reared fish (5.65 kg, Kf: 1.23, pH: 7.29, muscle temperature: 6.68 ℃) were killed and immediately tempered in three different containers. Muscle temperatures after filleting (<3 h postmortem) of the three groups were 2.08 ℃ (hereafter named T-2); 9.07 ℃ (hereafter named T-9), and 14.09 ℃ (hereafter named T-14), respectively. The pH after filleting was significantly low for T-14 (6.93) followed by T-9 (7.06) and T-2 (7.22). Raised temperature at point of filleting was found to significantly alter development of rigor mortis, which subsequently affected muscle pH and the reflective properties of the fillet surface during 14 days' ice storage. Of cold-smoked fillets, however, a more distinct effect of raised temperature was observed on visual perception resulting in lighter and more yellowish cold-smoked fillets after 14 days' storage. In addition, raised temperature also affects the development of muscle pH in cold-smoked fillets during refrigerated storage. No effects of raised muscle temperature were found regarding drip loss, water-holding capacity, or fillet firmness either for raw- or cold-smoked fillets throughout the storage period.

This study investigated the effect of sub-chilling whole gutted salmon and sub-chilled storage at −1 °C in modified-atmosphere packaging in two recyclable mono-material trays (CPET, HDPE). Quality parameters were measured, including water-holding properties, salt content, color, texture, lipid oxidation, and sensory and microbiological shelf life. The oxygen transmission rate was measured for the packages. Compared to traditional fish storage on ice, sub-chilling gave a 0.4% weight gain, better water-holding capacity, and higher salt content. The sub-chilled fish gave a significantly better sensory quality and microbiological shelf life of up to 49 days. Photobacterium was the dominating bacteria during storage. Salmon packaged in CPET trays had a higher drip loss than HDPE trays, but a lower rate of lipid oxidation (1-penten-3-ol). Our results showed the feasibility of significantly extending shelf life with sub-chilling, removing the need for ice. Moreover, using recyclable trays for packaging contributes to a circular economy without compromising food quality.

The demand for high‐quality, convenient, and sustainable salmon products represents a potential for value‐added product development and novel packaging solutions. Soluble gas stabilization (SGS) technology, which applies dissolved CO ₂ in the product before packaging, represents a novel approach to retain product quality and prevent microbiological deterioration during cold storage of pre‐rigor filleted salmon loins. The present study aimed to examine the solubility of CO ₂ in salmon loins as affected by rigor status. In addition, the effect of predissolved CO ₂ on the overall quality of pre‐rigor vacuum‐packed Atlantic salmon ( Salmo salar L.) was investigated during storage at 4°C. The CO ₂ pretreatment was conducted, exposing loins to 100% CO ₂ for 18 h at 4°C (the control group was kept in air at 4°C) before repackaging and storage for 15 days. Dissolved CO ₂ in the muscle (equilibrium achieved four days post packaging) was slightly higher in pre‐rigor than post‐rigor salmon loins ( p _equilibrium  = 0.006). Moreover, the overall spoilage ( H value) and microbiological stability of salmon fillets stored in SGS‐vacuum were significantly improved compared to vacuum‐packed loins ( p < 0.05). The results demonstrate that SGS technology can maintain the overall quality of pre‐rigor vacuum‐packed salmon loins without introducing the high gas‐to‐product volume ratio recognized by modified atmosphere packaging. Thus, the application of SGS technology on pre‐rigor loins can lead to higher economic gain and environmental benefits due to the reduced amount of required packaging material and reduced food waste. Practical Application: CO ₂ can be dissolved in pre‐rigor salmon loins before vacuum packaging to increase product shelf life during cold storage.