Atlantic Salmon Fillets Research Articles

FilletCam AI: A handheld tool for precise fillet color profiling of Atlantic salmon and rainbow trout

High-throughput and objective color measurements of fish fillets are crucial for quality control and establishing pricing benchmarks. While fillet color scoring traditionally relies on subjective visual inspection using color reference cards or labor-intensive color measurement using a colorimeter, this study aims to develop a smart handheld device (FilletCam AI, hereafter referred to as ‘FilletCam’) for precise and rapid profiling of fish fillet color. FilletCam comprises an imaging sensor integrated with an embedded computing unit for image acquisition. A graphical user interface (GUI) was developed to streamline data collection, analysis, visualization, compilation, and data sharing with authorized users. An Artificial Intelligence (AI) model was developed and deployed on the edge for region-of-interest (ROI) detection. A single-stage YOLOv8 model was trained on a custom image dataset comprised of Atlantic salmon (Salmo salar) and rainbow trout (Oncorhynchus mykiss) fillet images to detect the fillet and color palette with their respective SalmonFan™ (SF) score on the reference card. Delta E metric was adopted to compare the color of the fillet and reference color shades on the SF card. The SF score corresponding to the lowest Delta E value was assigned to the fillet. The object detection model performed well and achieved a mean average precision (mAP0.5) of 99.5 % and an F1 score of 0.99. The FilletCam-predicted fillet color scores were compared with the expert ratings and colorimeter scores to evaluate the performance of the developed tool. The minimum Delta E values for FilletCam were consistently lower than those for the colorimeter, indicating FilletCam's ability to detect minor color differences accurately. FilletCam exactly predicted the color scores at 73 % of instances compared to 30 % of instances for the colorimeter. Additionally, for only 3 % of instances, the predicted SF score deviated by more than two points. Overall, the developed research prototype shows promise as a valuable digital tool for the fish processing and retail industries.

Efficacy Evaluation of Chlorine Dioxide and Hypochlorous Acid as Sanitisers on Quality and Shelf Life of Atlantic Salmon (Salmo salar) Fillets.

Microbial contamination during seafood processing can often lead to a reduction in shelf life and the possibility of food-borne illnesses. Sanitisation with chlorine-based products during seafood processing is therefore sometimes undertaken. This study compared the effects of two sanitisers, chlorine dioxide (ClO2) and hypochlorous acid (HOCl) at their suggested concentration (5 ppm and 10 ppm; 50 ppm and 100 ppm respectively), on physical, chemical, and microbial qualities of Atlantic salmon (Salmo salar) fillets throughout 7 days of simulated retail display refrigeration. Parameters used for assessment included quality index (QI), drip loss, colour, texture, histology, total volatile base nitrogen (TVB-N), lipid oxidation (malonaldehyde, MDA), pH, and total viable count changes. Results indicated that whilst drip loss increased over the storage time, day 4 and 7 drip loss in both sanitisers decreased significantly compared with the control. There was a linear relationship (R > 0.70) between QI and storage time in all treatments, particularly in regard to skin brightness, flesh odour, and gaping parameters, but treatment differences were not present. Texture parameters including gumminess, chewiness, and hardness increased over time in the control whilst both sanitiser treatments seemed to provide protective effects against texture hardening during storage. The observed softening effects from the sanitiser treatments were aligned with microstructural and cytological changes in the histology results, as evidenced by a reduced fibre-fibre adhesion, myodigeneration, and an increase in interfibrillar space over storage time. Colour, especially chroma (C*), was shown to decrease over time in control, whereas insignificant protective effects were observed in both sanitiser treatments at day 7. Irrespective of treatment and storage time, MDA levels exceeded the acceptable limit on all days, whilst TVB-N levels were below the critical limit. Although pH was influenced by treatment and storage time, the pH was within the normal range. Microbiological results showed that with sanitiser addition, TVC was below the permissible level (106 CFU/g) until day 4 but ClO2 ice (5 ppm), ClO2 (10 ppm), and HOCl (100 ppm) treated fillets all exceeded the limit on day 7. The mixed results on the effect of sanitiser addition on fillet quality and shelf life suggested that further investigation on pathogen reduction, sanitiser introductory method, as well as testing the same treatments in low-fat fish models would be recommended.

Effect of Oscillating Magnetic Fields (OMFs) and Pulsed Electric Fields (PEFs) on Supercooling Preservation of Atlantic Salmon (Salmo salar L.) Fillets.

Salmon, rich in protein and omega-3 fatty acids, has a short shelf life of 1 to 3 days when stored at 2 to 8 °C. Freezing, used for long-term preservation, often results in ice crystal formation. Ice crystals can cause structural damage, leading to cell wall rupture, which can affect the texture and cause nutrient loss. Ultimately, this process reduces the overall quality of the salmon. Supercooling, which cools food below its freezing temperature without forming ice crystals, offers an alternative. This study investigated the effects of oscillating magnetic fields (OMFs) and pulsed electric fields (PEFs) on ice crystal formation during salmon supercooling. The results showed that using OMFs and PEFs in supercooling reduced the storage temperature of salmon, maintaining a similar thiobarbituric acid reactive substances (TBARS) value to that of frozen and refrigerated samples. There was no significant difference in meat color between the fresh and frozen samples, and drip loss weight was comparable between the fresh and supercooled samples. The microbiological counts were the lowest in the supercooled samples compared to the frozen and refrigerated ones. These findings suggest that supercooling storage with OMFs and PEFs can mitigate quality degradation in salmon typically associated with freezing.

The quality of frozen-thawed Atlantic salmon (Salmo salar L.) fillets as affected by sub-chilling before freezing.

To maintain the quality of frozen Atlantic salmon after thawing and highlight the potential for moving from air fright to boat for long-distance export, a study was designed to investigate the effects of sub-chilling before rapid freezing on the quality of thawed fillets. Atlantic salmon chilled on wet ice before filleting and freezing was used as a control for the experimental factor chilling, whereas fresh fillets were used for the frozen-thawed samples. The pre-freezing chilling method interacted with the storage protocol and significantly affected the product. For fresh stored fillets, sub-chilling improved the microbiological and textural stability and degradation of proteins. After 1 month of frozen storage, sub-chilled fillets gave better color and textural properties, less adenosine triphosphate degradation and protein denaturation. In addition, sub-chilled 4-month-frozen fillets also showed improved microbial stability compared to those initially chilled with ice before frozen storage. Quality was lost as a function of storage. Fresh fillets generally had higher bacterial counts, surface breaking force, firmness, hue and contents of inosine monophosphate, and lower drip loss and inosine (HxR) levels than those stored frozen-thawed. Moreover, 4-month-frozen fillets had higher HxR levels and lower psychrotrophic viable count growth than those that were frozen for 1 month. The time fillets were stored frozen did not profoundly affect their quality. It is concluded that a frozen product might be competitive with a fresh product when sub-chilling is performed before freezing, especially when including the environmental benefits of frozen export by boat rather than air freight. © 2024 The Author(s). Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Efficacy of Electrolyzed Oxidizing Ice Against Bacteria on Atlantic Salmon (Salmo salar) and Salmon Fillets

ABSTRACT This study has improved the sanitation of head-on gutted (HOG) Atlantic salmon (Salmo salar) by using neutral electrolyzed oxidizing water (NEW) ice. NEW and neutral electrolyzed oxidizing ice (NEI) were tested on Listeria monocytogenes and Pseudomonas aeruginosa-contaminated salmon fillet skin. Treatment by storage with melting NEI reduced P. aeruginosa by 1.1 and 2.4 log CFU/cm2, respectively. Storage with 100 ppm NEI suppressed L. monocytogenes by 1 log CFU/cm2. In the industry, storage of HOG salmon with a concentration of 100 ppm of NEI could therefore be used for pre-treatment to reduce microbial contamination before filleting.

Effects of nano freezing-thawing on myofibrillar protein of Atlantic salmon fillets: Protein structure and label-free proteomics

This study investigated the impact of magnetic nanoparticles (MNPs) -assisted cryogenic freezing integrated with MNPs combined microwave thawing (NNMT) on the structural integrity of myofibrillar proteins and alterations in protein profiles in salmon fillets. The NNMT showed the lowest myofibrillar fragmentation index (MFI) value (2.73 ± 0.31) among the four freezing-thawing groups. The myofibrillar structure exhibited the highest level of integrity, while the myofibrillar proteins demonstrated minimal aggregation and displayed the most stable secondary and tertiary structures in response to NNMT treatment. Compared with the other three treatments, NNMT exhibited a high abundance of ionic and hydrogen bonds, resulting in stronger interactions between the proteins and water molecules. The label-free proteomics analysis revealed that different freezing-thawing methods primarily affected the cytoskeletal proteins, with collagen and myosin being down-regulated due to degradation caused by cold stress and recrystallization. Additionally, NNMT demonstrated a superior capability in stabilizing salmon cytoskeletal proteins.

Cell-based, cell-cultured, cell-cultivated, cultured, or cultivated. What is the best name for meat, poultry, and seafood made directly from the cells of animals?

To be sold in the United States, meat, poultry, and seafood products made from cultured cells must be labeled with a “common or usual name” to help consumers understand what they are purchasing. The terms “Cultured,” “Cultivated,” “Cell-Cultured,” “Cell-Cultivated,” “Cell-Based” and a control (without a common or usual name) were tested using an online experiment. Two regulatory criteria were assessed: that the term distinguishes the novel products from conventional products, and appropriately signals allergenicity. Three consumer acceptance criteria were assessed: that the term is seen as appropriate, does not disparage the novel or conventional products, nor elicit perceptions that the products are unsafe, unhealthy, or not nutritious. Each term was shown on packages of frozen Beef Filets, Beef Burgers, Chicken Breasts, Chicken Burgers, Atlantic Salmon Fillets, and Salmon Burgers. A representative sample of 4385 Americans (18 + ) were randomly assigned to view a single product with a single term or the control. Consumers’ ability to distinguish tested terms from conventional products differed by product category. “Cultured” and “Cultivated” failed to adequately differentiate the novel products from “Wild-Caught and Farm-Raised” salmon products. “Cultivated” failed to differentiate the novel Beef Filet product from “Grass-Fed” Beef Filets. “Cell-Cultured,” “Cell-Cultivated,” and “Cell-Based” each signaled that the products were different from conventional products across the proteins, and signaled allergenicity, meeting the two key regulatory criteria. They were not significantly different on most consumer perception measures. However, “Cell-Cultured” may have slightly better consumer acceptance across the novel beef, chicken, and salmon products, recommending its universal adoption.

Eumelanin Detection in Melanized Focal Changes but Not in Red Focal Changes on Atlantic Salmon (Salmo salar) Fillets

Superficial discolored spots on Atlantic salmon (Salmo salar) fillets are a serious quality problem for commercial seafood farming. Previous reports have proposed that the black spots (called melanized focal changes (MFCs)) may be melanin, but no convincing evidence has been reported. In this study, we performed chemical characterization of MFCs and of red pigment (called red focal changes (RFCs)) from salmon fillets using alkaline hydrogen peroxide oxidation and hydroiodic acid hydrolysis. This revealed that the MFCs contain 3,4-dihydroxyphenylalanine (DOPA)-derived eumelanin, whereas the RFCs contain only trace amounts of eumelanin. Therefore, it is probable that the black color of the MFCs can be explained by the presence of eumelanin from accumulated melanomacrophages. For the red pigment, we could not find a significant signature of either eumelanin or pheomelanin; the red color is probably predominantly hemorrhagic in nature. However, we found that the level of pigmentation in RFCs increased together with some melanogenic metabolites. Comparison with a “mimicking experiment”, in which a mixture of a salmon homogenate + DOPA was oxidized with tyrosinase, suggested that the RFCs include conjugations of DOPAquinone and/or DOPAchrome with salmon muscle tissue proteins. In short, the results suggest that melanogenic metabolites in MFCs and RFCs derive from different chemical pathways, which would agree with the two different colorations deriving from distinct cellular origins, namely melanomacrophages and red blood cells, respectively.

Active and Intelligent Four-Layer Films Based on Chitosan, Gelatin, Furcellaran and Active Ingredients—Preparation, Characterisation and Application on Salmon

Innovatively, four-layer, active biopolymer films based on furcellaran, chitosan and gelatin as well as active compounds (curcumin, capsaicin, AgNPs, montmorillonite and gelatin hydrolysate) were obtained. The films showed strong antioxidant effects. Adding active ingredients caused increased enthalpy change value (ΔH) and thermal stability. The potential application of the film was analysed by storing Atlantic salmon fillets in the material. The films showed an active effect. This effect was the strongest during the first 3 days of storage. Compared to the synthetic LDPE film, the active film showed a total 0.81 log/CFU lower microbial count on the 12th day of storage. Lipid oxidation was not delayed in the salmon. Nonetheless, the results indicate high applicative potential of the composites.

Arsenic speciation and arsenic feed-to-fish transfer in Atlantic salmon fed marine low trophic feeds based blue mussel and kelp

BackgroundAquaculture aims to reduce the environmental and climate footprints of feed production. Consequently, low trophic marine (LTM) resources such as blue mussels and kelp are potential candidates to be used as ingredients in salmon feed. It is relevant to study potential undesirables associated with their use, as well as assessing food safety by investigating their transfer from feed-to-fish. The marine biota is well known to contain relatively high levels of arsenic (As), which may be present in different organic forms depending on marine biota type and trophic position. Thus, it is important to not only obtain data on the concentrations of As, but also on the As species present in the raw materials, feed and farmed salmon when being fed novel LTM feed resources. MethodsAtlantic salmon were fed experimental diets for 70 days. A total of nine diets were prepared: four diets containing up to 4 % fermented kelp, three diets containing up to 11 % blue mussel silage, and one diet containing 12 % blue mussel meal, in addition to a standard reference diet containing 25 % fish meal. Concentrations of As and As species in feeds, faeces, liver and fillet of Atlantic salmon were determined by inductively coupled plasma mass spectrometry (ICP-MS) and high-performance liquid chromatography coupled to ICP-MS (HPLC-ICP-MS), respectively. ResultsThe use of kelp or blue mussel-based feed ingredients increased the concentration of total As, but maximum level as defined in Directive 2002/32 EC and amendments was not exceeded. The concentrations found in the experimental feeds ranged from 3.4 mg kg−1 to 4.6 mg kg−1 ww. Arsenic speciation in the feed varied based on the ingredient, with arsenobetaine dominating in all feed samples (36–60 % of the total As), while arsenosugars (5.2–8.9 % of the total As) were abundant in kelp-included feed. The intestinal uptake of total As ranged from 67 % to 83 %, but retention in fillet only ranged from 2 % to 22 % and in liver from 0.3 % to 0.6 %, depending on the marine source used. Fish fed feeds containing blue mussel showed higher intestinal uptake of total As when compared with fish fed feeds containing fermented kelp. Fish fed fermented kelp-based feeds had higher retained concentrations of total As when comparing with fish fed feeds containing blue mussel. Despite relatively high intestinal uptake of total As, inorganic and organic As, the retained concentrations of As did not reflect the same trend. ConclusionAlthough the use of LTM feed ingredients increased the level of total As in this feeds, salmon reared on these diets did not show increased total As levels. The well-known toxic inorganic As forms were not detected in salmon muscle reared on LTM diets, and the non-toxic organic AsB was the dominant As species that was retained in salmon muscle, while the organic AsSug forms were not. This study shows that speciation analysis of the LTM resources provides valuable information of the feed-to-fish transfer of As, needed to assess the food safety of farmed Atlantic salmon reared on novel low trophic feeds.

Differentiation and traffic of IgM+ B cells between focal dark spots in skeletal muscle of Atlantic salmon, lymphoid and adipose tissues.

Focal dark spots (DS) in farmed Atlantic salmon fillets contain a significant number of B cells as revealed by the high abundance of immunoglobulin (Ig) transcripts in transcriptome data. The immune response in DS remains unknown while they represent a major problem in commercial aquaculture. Here, we characterized the diversity and clonal composition of B cells in DS. Sixteen gene markers of immune cells and antigen presentation were analyzed with RT-qPCR. All genes expression showed a positive correlation with DS area and intensity. The flatter the DS, the higher the expression of cd28, csfr, ctla, igt, and sigm, the lower expression of cd83 and btla, and the larger the cumulative frequency within DS. The expression of most of the analyzed immune genes, including three Ig types and markers of B cells was lower in DS than in the lymphatic organs, head kidney and spleen, but significantly higher compared to skeletal muscle. High levels of ctla4 and cd28 in DS might indicate the recruitment of T cells. Sequencing of IgM repertoire (Ig-seq) assessed migration of B cells by co-occurrence of identical CDR3 sequences in different tissues. The combination of gene expression and Ig-seq revealed the presence of several stages of B cell differentiation in DS. B cells at the earliest stage, with high ratio of membrane to secretory IgM (migm and sigm), showed minor Ig repertoire overlap with other tissues. Further differentiation stage (increased sigm to migm ratio and high expression of pax5 and cd79) was associated with active movement of B cells from DS towards lymphatic organs and visceral fat. Traffic and expression of immune genes decreased at later stages. These B cells could be involved in a response directed against viruses, pathogenic or opportunistic bacteria in DS. Seven of eight fish were positive for salmon alphavirus, and levels were higher in DS than in unstained muscle. PCR with universal primers to the 16S rRNA gene did not detect bacteria in DS. Although the evolution of DS most likely implies local exposure to antigens, neither this nor previous studies have found a necessary association between DS and pathogens or self-antigens.

Nano Freezing-Thawing of Atlantic Salmon Fillets: Impact on Thermodynamic and Quality Characteristics.

The presence of magnetic nanoparticles (MNPs) suppresses ice nucleation and growth during freezing and thawing. In this study, the effects of MNPs-assisted cryogenic freezing integrated with MNP-combined microwave thawing (NNMT) on the thermodynamic and quality changes of salmon fillets were investigated. Results have shown that NNMT raises Tg (glass transition temperature) and Tmax (transition temperature), thus improving the storage stability of salmon fillets. MNPs-assisted freezing and thawing treatment, especially NNMT treatment, significantly improved the water holding capacity, texture, color, and other quality characteristics of salmon fillets. In addition, the lipid and protein oxidation degrees of the NNMT treatment were the lowest, while the myofibrillar protein solubility of NNMT was the highest (87.28%). This study demonstrated that NNMT has minimal impact on the freezing-thawing quality of salmon fillets, making it a more suitable option for the preservation of aquatic foods.

Türk Süpermarketlerindeki İthal Balıklarda Zoonotik Anisakis Larvalarının Varlığına İlişkin Devam Eden Veriler: Dondurulmuş Atlantik Uskumru (Scomber Scombrus) ve Füme Atlantik Somonu (Salmo Salar)

Anisakis pegreffii and A. simplex sensu stricto (s.s.) are the main etiological agents causing human anisakiasis. Here, we aimed to investigate based on the pepsin digestion method of the occurrence of Anisakis larvae in imported deep-frozen whole Atlantic mackerel (Scomber scombrus) from FAO 27 to Turkey and smoked Norwegian farmed Atlantic salmon fillets (Salmo salar) between 2018 and 2019. A total of 100 whole Atlantic mackerel and 180 Atlantic salmon fillets were randomly sampled from local Turkish supermarkets. No Anisakis larvae were detected in smoked Atlantic salmon fillets. In total, 827 Anisakis larvae were found in mackerel, and the prevalence was 68% (68/100). The mI and mA of Anisakis larvae in mackerel were 13.1 and 8.2, respectively. Whereas the 95.28% (788/827) of the Anisakis larvae were found in abdominal cavity/viscera, the 4.72 % (39/827) of the larvae in the muscle. The prevalence and mI of Anisakis larvae in the abdominal cavity/viscera and muscle of mackerel was 63.0% (63/100) and 42.0% (42/100), and 12.5 and 0.9, respectively. The subsample of 100 larvae was molecularly identified by ITS RFLP patterns. The 99 (99.0%) larvae were identified as A. simplex (s.s.), and 1 (1.0%) larva was A. pegreffii. Consequently, there is low or no risk of anisakiasis in smoked farmed Atlantic salmon for Turkish consumers. The 42.0% prevalence of zoonotic Anisakis species larvae in imported Atlantic mackerel fillets could have public health risk in Turkish consumers for anisakiasis or allergy.

INFLUENCE OF ELECTROCHEMICALLY ACTIVATED SOLUTIONS ON THE FATTY ACID PROFILE OF FOOD SYSTEMS

The emergence of new types and methods of food processing requires studying the impact on the compo-nents of food systems. Fish products are an important part of the human diet, but as a result of storage, their quality and safety indicators are reduced. An effective way to ensure the biological safety of fish raw materials is the use of electrochemically activated solutions (ECAS) obtained by high-voltage diaphragm electrolysis. The aim of the study was to study the effect of various concentrations of ECAS on the fatty acid profile of food systems using the example of fish oil from Atlantic salmon (Salmo salar) fillet during the shelf life. In the experiments, a ready-made ECAS with an active chlorine concentration (hereinafter Cach) of 500 mg/l (0.05%) was used, from which working ECAS were prepared with a dilution of 50% and 15%, which corresponds to Cach – 250 mg/l (0.025%) and Cach – 75 mg / l (0.0075%). The concentration of ECAS was selected experimentally in order to determine the optimal concentration at which the de-struction of fatty acids (hereinafter FA) of the studied samples did not occur. The determination was car-ried out by gas chromatography using a Crystal-2000M chromatograph. Comparison was made with con-trol samples. Identification of the peaks of FA methyl esters of the tested samples made it possible to de-termine the recommended working concentration of active chlorine ECAS equal to 75 mg/l, at which the content of polyunsaturated fatty acids does not statistically decrease. The research results can be used to ensure the quality and biological safety of fish fillets, taking into account the specific effects of ECAS on individual components of food systems.

Mechanical processing of Phaeodactylum tricornutum and Tetraselmis chui biomass affects phenolic and antioxidant compound availability, nutrient digestibility and deposition of carotenoids in Atlantic salmon

Cell walls of microalgae differ both in terms of chemical composition and architecture. Certain characteristics of cell walls limit both the effectiveness of extraction of valuable constituents and nutrient bioavailability and bioaccessibility in fish. We first investigated the potential of bead milling to disrupt cell walls to improve extractability of bioactive compounds from Phaeodactylum tricornutum and Tetraselmis chui. We also evaluated the effect of the mechanical treatment on i) digestibility of nutrients in the two microalgae and ii) fatty acid and pigment content of fillet of Atlantic salmon fed the algae diets.Cell wall disruption facilitated efficient release of total phenolic compounds (TPC), chlorophyll A, chlorophyll B and total carotenoids from both microalgae species, but increased only the total antioxidant capacity (TAC) of T. chuii. The polyphenol profile varied between the two species; we identified 2 and 6 polyphenols from P. tricornutum and T. chui, respectively.For the feeding experiment, microalgae biomass, intact or cell wall disrupted (90.7 and 76.4% disruption degree for T. chui and P. tricornutum, respectively), were mixed with the other feed ingredients. Atlantic salmon (315 g start weight / 55 fish per tank) were fed one of the five extruded experimental diets (a fishmeal-based reference diet and four feeds with 30% of the whole or broken microalgae biomass added to the reference diet). The digestibility of protein in the P. tricornutum was significantly higher compared to that of T. chui. Breaking the cell walls by bead milling caused a significant improvement in digestibility of protein in T. chui. The apparent digestibility coefficient of lipid was higher in P. tricornutum and bead milling improved the digestibility of the two algae. However, bead milling did not favourably change the fatty acid profile of Atlantic salmon. At the end of the feeding trial, P. tricornutum-fed fish had significantly improved pigmentation, probably due to the higher content of fucoxanthin and fucoxanthinol compared to the fish fed the reference diet. The main conclusion from the mechanical processing of the microalgae is that bead milling can increase i) the extractability of polyphenols and pigments, ii) the digestibility of lipid in both algae while the effect on protein was improved only for T. chui. Furthermore, P. tricornutum can be considered a natural pigment source in the feeds of Atlantic salmon.

Evaluating the effects of plasma-activated slightly acidic electrolyzed water on bacterial inactivation and quality attributes of Atlantic salmon fillets

In this study, an intervention non-thermal processing technology plasma-activated slightly acidic electrolyzed water (PASW) was developed to better preserve salmon fillets. Compared to the plasma-activated water (PAW) and slightly acidic electrolyzed water (SAEW), PASW treatment was found to be more effective in inactivating microorganisms. After PAW, SAEW, or PASW treatment for 120 s, the population of Shewanella putrefaciens (S. putrefaciens) was reduced by 2.04, 2.62 and 2.08 Log CFU/mL (P < 0.05) using plate counts, respectively. The test for the leakage of nucleic acids and protein in intracellular contents confirmed that PASW caused serious damage to the microbial cell structural integrity compared to that alone PAW or SAEW. Meanwhile, scanning electron microscopic observations also showed that PASW caused apparent bacterial structural changes. Besides, the PASW treatment did not alter color and textural properties of salmon fillets, and restrained lipid oxidation as compared to the control and SAEW treatments. In all, this study compared the bacterial inactivation mechanisms for PAW, SAEW, and PASW, and suggested that PASW was effective in inactivating S. putrefaciens of salmon fillets. Industrial relevancePlasma-activated slightly acidic electrolyzed water, an emerging technology in food processing, can be a potential green technology for the processing of aquatic food products. PASW treatment had higher disinfection efficacy than that of SAEW or PAW treatment alone, and no adverse effect on the quality of Atlantic salmon fillets. These results boost knowledge in the food preservation field, as well as the application of non-thermal processing in the food industry.

Using renowned chefs for VeriTaste™ as a sensory method analysis in food products – A comparison of Atlantic salmon stored in refrigerated seawater and on ice

Sensory evaluation is an important quality analysis for examining the characteristics of a food product. This study presents a new sensory analysis method using renowned chefs, branded Veritaste™, to evaluate raw and cooked fillets of Atlantic salmon originating from refrigerated seawater (RSW) versus traditional ice whole fish storage. Quality parameters were also studied, including the fillet index method and cook loss. The raw fillets from the RSW-stored fish had a more distinct salty taste compared to the traditionally stored fish. In addition, the RSW-stored salmon gave a lower cook loss. Otherwise, there were minimal differences in the sensory parameters observed and the fillet index measurements. Both Veritaste™ and the fillet index measurements showed that judges significantly influence the sensory quality parameters. It is concluded that Veritaste™ can serve as supplementary information in addition to the common sensory analyses done today. This method has the potential to be further improved, optimised, and extended to other food products.

Thaw rigor in Atlantic salmon (Salmo salar) fillets, as affected by thawing rate and frozen storage time

The influence of stress, storage time and thawing regimes was investigated with respect to rigor development and other related physical traits, on farmed Atlantic salmon. The fish were sampled from a commercial slaughterhouse production line, filleted, vacuum packaged and quickly frozen, pre-rigor. The investigated parameters were selected to maintain fresh-like quality.No significant (p > 0.600) effects were seen between rigor contraction and stress parameters measured at time of slaughter. Frozen storage time significantly (p = 0,003) affected contraction, while no effect of thawing method (p = 0.824) was detected. The liquid loss of the frozen groups was significantly (p = 0.019) affected by thawing method, while frozen storage time had no significant (p = 0.087) effect. Further, drip loss was not affected by fillet contraction (p = 0.075). Increasing frozen storage time significantly (p = 0.042) decreased the redness and thawing in air rather than water significantly (p = 0.015) decreased the yellowness of the fillets. Fillet stored for 1 month had significantly (p = 0.004) lower F-break force, while no significant (p > 0.227) effect of storage or thawing was seen on hardness. Frozen fillets were comparable to 7 days old vacuum packaged fresh fillets stored on ice for seven days, albeit with some increase in drip loss and some differences in texture, but with comparable color and fillet contraction.

Rib abnormalities and their association with focal dark spots in Atlantic salmon fillets

Focal dark spots (DS) represent the most common quality problem in farmed Atlantic salmon (Salmo salar L.). DS are predominantly located in the cranio-ventral region of the fillet, that is characterized by the presence of ribs. The current study explores the possible association between abnormal rib morphology and DS types and the frequency of rib abnormalities in the rib cage by X-ray imaging. The fish used were salmon from a common smolt group that were sampled in freshwater (smolt farm) and subsequently two, five, eight and 14 months after sea transfer to small-scale land-based tanks or commercial sea-cages. Large size wild salmon were used as additive. Rib abnormalities were found in most fish, with a consistent number of four abnormalities per rib cage side of smolts, land-based and wild salmon. After transfer from freshwater to sea-cages, there was an abrupt increase from four to 10 abnormal ribs per rib cage side, mainly explained by low-density and shorter ribs. The number of abnormal ribs stabilized in further samplings at around eight abnormalities per rib cage side. In contrast to wild salmon, abnormalities in farmed salmon were symmetrically concentrated in the center of the rib cage in mid and distal parts of ribs, where also most DS were concentrated. No typical black DS were observed in smolts, salmon farmed in land-based tanks or wild salmon. Two months after transfer to sea-cages, 15% of the salmon had fillet-red DS, while fillet-black DS were observed five months after sea transfer (30%). The prevalence of fillet-red DS oscillated between 15 and 3% during the seawater phase, while fillet-black DS increased until the eighth month after seawater transfer, stabilizing in further samplings at 43–45%. The prevalence of rib abnormalities was 1.6 times higher in fillet-black DS than in control tissue, and 2 times higher for peritoneum DS, principally because of various forms of bent-, and broken ribs. There was an association between rib abnormalities and DS, although additional factors influenced the final DS phenotype. Preventing damaging incidents in the late smolt phase and sea-cage operations can likely reduce the prevalence of abnormal ribs and DS.

Chemical composition of whole body and fillet of slaughter sized Atlantic salmon (Salmo salar) and rainbow trout (Oncorhynchus mykiss) farmed in Norway in 2020

The fish is the end-product in fish farming, but updated data on the composition of slaughter sized farmed salmon and trout are still scarce. The body composition of farmed salmonids changes over time as farming technology, farming routines, feed and genetics develops. Knowledge of the body composition of the farmed fish thus depends on data on today’s produced fish. The body composition also varies with time of the year, geography, feed composition and feed intake. Analysis of samples representative of the whole Norwegian production of salmon and trout requires fish collected from the different geographic areas of production, sampled at different times throughout the year, and fish fed feeds from different feed producers.Atlantic salmon and rainbow trout was collected in summer and in winter. Salmon was collected at four different locations, and trout at two different locations at each sampling time. Whole body and fillet of salmon and trout was analyzed. This study reports the average content of energy, dry matter, ash, crude protein, crude lipids, iron, potassium, calcium, copper, magnesium, sodium, zinc and phosphorus in whole body and fillet of Atlantic salmon and rainbow trout produced in Norway in 2020. Moreover, are the amino acid profiles and the fatty acid profiles given.