Atlantic Salmon Fillets Research Articles

Atlantic Salmon (Salmo salar) Performance Fed Low Trophic Ingredients in a Fish Meal and Fish Oil Free Diet.

To evolve fish farming in an eco-efficient way, feed production must become less dependent on forage fish-based ingredients and make more use of low trophic level organisms, including microalgae, higher plants, as filter feeding organisms and other ingredients with low competition to established food value chains. Diets nearly free of fish meal and fish oil are not a novelty but are often composed of complex mixtures, containing supplements to meet the farmed animal’s nutritional requirements. Sustaining a growing aquaculture production, maintaining at the same time fish health, welfare, and profitability, and meeting strict environmental and food safety demands, is challenging and requires new technologies, great investments, and more knowledge. A benchmarking feeding trial was performed to demonstrate the main effects of four low trophic raw materials on Atlantic salmon (Salmo salar) growth, metabolism, skin health and fillet quality. To this end, a diet was produced to contain commercially relevant levels of fresh high quality organic FM and FO and was used as a control in the trial (FMFO). Heterotrophically produced Schizochytrium limacinum biomass was used to replace organic FO (HM diet). Spray dried cell wall disrupted biomass of the phototrophically cultured diatom Phaeodactylum tricornutum replaced partly FM and FO (PM diet). Black soldier fly (Hermetia illucens) larvae meal and tunicate (Ciona intestinalis) meal, were used to produce the diets BSFL and TM, respectively, replacing large parts of FM as compared to the FMFO. A fifth test diet was produced combining all test raw materials and removing all FM and FO (0FM0FO diet). All test ingredients were well accepted sustaining high growth rates (TGC values near 4) and feed efficiency (FCR values below 0.9) in salmon showing good gut health and normal metabolic responses. However, none of the treatments reached the growth performance of FMFO. Additional differences between test and control treatments were identified in dietary nutrient apparent digestibility, fish biometrics, blood metabolites and fillet and skin composition. Extensive raw material and dietary chemical characterisation was performed to provide insight on potential shortcomings in the novel low trophic level ingredients which can possibly be overcome combining complementary raw materials.

A feasibility study on nondestructive classification of frozen Atlantic salmon (Salmo salar) fillets based on temperature history at the logistics using NIR spectroscopy.

Temperature fluctuation commonly occurs in the cold chain leading to complete or partial thawing and refreezing of frozen products resulting in a multifrozen product. Such oscillation of temperature could cause significant quality reduction compared to single frozen products. This study was designed to differentiate frozen Atlantic salmon fillets based on the level of temperature fluctuation. Near-infrared spectroscopy (NIRS) coupled with chemometrics was used to classify the frozen fillets stored at no fluctuation (NF), low fluctuation (LF), high fluctuation (HF), and very high fluctuation (VF) temperature. Using spectral profiles obtained at both frozen and thawed states, fillets were classified based on the level of temperature fluctuation by partial least squares discriminant analysis (PLS-DA). The thawed samples showed better classification accuracy (71%) than frozen samples (66%) in a four-class model. Considering the small variation within the first two (NF, LF) and the last two (HF, VF) groups, a two-class classification model was developed using thawed samples, and the obtained model correctly classified the two groups ([NF, LF] and [HF, VF]) with 100 % classification accuracy. Protein- and water-related changes were found important to distinguish the fillets. Based on these findings, the four-class prediction model is found insufficient to be used for nondestructive determination of temperature history of frozen fillets. However, the two-class prediction model with further external validation can be applied to determine the level of temperature fluctuation particularly using fillets scanned at thawed state. PRACTICAL APPLICATION: NIR spectroscopy can be used to evaluate the degree of temperature fluctuation and thus related quality loss throughout the logistics of frozen Atlantic salmon fillets. Researchers, food control authorities, and the retail industry could be the primary beneficiaries of this research output.

Novel active biopackaging incorporated with macerate of carob (Ceratonia siliqua L.) to extend shelf-life of stored Atlantic salmon fillets (Salmo salar L.).

Two antioxidant bio-based packaging materials incorporated with an 8% aqueous solution of carob seed ethanol macerate (CSE) or 8% aqueous solution of carob seed acetone macerate (CSA) were developed. Fresh salmon fillets were packaged in active and control films and stored at refrigeration temperature at 4 ± 1 °C. The quality was evaluated by sensory analysis, color, pH, water holding capacity and drip loss, thiobarbituric acid reactive substances, and total volatile basic nitrogen. The CSE and CSA samples presented satisfactory off-odor and overall acceptability results than the control samples until the 5th storage day. For color analysis, active samples preserved better the characteristics of fresh salmon than the controls during the first storage days. The fresh salmon fillet covered with active packaging presented on the 5th storage day a lower values of pH (6.54 ± 0.05 and 6.60 ± 0.11), drip loss (3.17 ± 0.76 and 2.83 ± 0.29), thiobarbituric acid reactive substances (0.056 ± 0.033 and 0.088 ± 0.054) and total volatile basic nitrogen (30.04 ± 3.54 and 32.67 ± 4.81), whereas, the highest water holding capacity values (92.23 ± 1.09 and 92.91 ± 3.07) for CSE and CSA respectively, as compared to those of blank biopackaging.

Use of (Q)SAR genotoxicity predictions and fuzzy multicriteria decision-making for priority ranking of ethoxyquin transformation products

Ethoxyquin (EQ; 6-ethoxy-2,2,4-trimethyl-1,2-dihydroquinoline) has been used as an antioxidant in feed for pets and food-producing animals, including farmed fish such as Atlantic salmon. In Europe, the authorization for use of EQ as a feed additive was suspended, due to knowledge gaps concerning the presence and toxicity of EQ transformation products (TPs). Recent analytical studies focusing on the detection of EQ TPs in farmed Atlantic salmon feed and fillets reported the detection of a total of 27 EQ TPs, comprising both known and previously not described EQ TPs. We devised and applied an in silico workflow to rank these EQ TPs according to their genotoxic potential and their occurrence data in Atlantic salmon feed and fillet. Ames genotoxicity predictions were obtained applying a suite of five (quantitative) structure–activity relationship ((Q)SAR) tools, namely VEGA, TEST, LAZAR, Derek Nexus and Sarah Nexus. (Q)SAR Ames genotoxicity predictions were aggregated using fuzzy analytic hierarchy process (fAHP) multicriteria decision-making (MCDM). A priority ranking of EQ TPs was performed based on combining both fAHP ranked (Q)SAR predictions and analytical occurrence data. The applied workflow prioritized four newly identified EQ TPs for further investigation of genotoxicity. The fAHP-based prioritization strategy described here, can easily be applied to other toxicity endpoints and groups of chemicals for priority ranking of compounds of most concern for subsequent experimental and mechanistic toxicology analyses.

Depletion of oxytetracycline plus epi-oxytetracycline residues in rainbow trout (Oncorhynchus mykiss) and Atlantic salmon (Salmo salar) under field conditions in Chile

The objective of this research study was to estimate the withdrawal time (WT) for oxytetracycline (OTC), administered intraperitoneally to two species of salmonids, rainbow trout (Oncorhynchus mykiss) and Atlantic salmon (Salmo salar). This was done in salmonid farms during the fattening phase in seawater, under field conditions. Seven cages from different marine farms were included, each as an experimental unit, treated with an intraperitoneal dose of OTC (in a range from 20 to 35 mg kg−1). From each sea cage, 10 fishes were randomly selected for laboratory analysis at each sampling point after treatment, which were variable according to the harvest of each cage. All selected fish were treated with a single dose of two different commercial OTC formulations; Formulation A (OTC 30%) and Formulation B (OTC 20%), both extra label. Study was performed according to VICH GL 57 guideline. Samples were kept cold until laboratory analysis. Homogenized samples were analyzed using a mass triple quadrupole spectrometer (Waters®, Xevo TQ-S micro). The analytical method was optimized for use in the laboratory and an internal validation procedure was performed following European Commission Decision 2002/657/EC for linearity, recovery and precision. The detection range, including the limit of detection (LOD) and limit of quantification (LOQ), were calculated according to VICH GL49 guidance.According to the degree days obtained from the residue depletion study and those observed in the last sampling, most of the sampled cages had concentrations that allow the veterinary drug to be suitable for a market with a maximum residue limit (MRL) value of 200 μg kg−1, but not for a market with an MRL of 10 μg kg−1, as might be expected, regardless of the dose and commercial veterinary drug used. Depending on the considered MRL, withdrawal times ranged from 5390 to 1676- and 4061–1641-degree days, for rainbow trout and Atlantic salmon, respectively. These estimates, obtained from field samples, can provide references regarding the WTs that must be considered in order to avoid the presence of OTC + 4-epi-OTC residues in Atlantic salmon and rainbow trout fillets, and thus protect the consumer health. Further studies are needed to assess the impact of other factors on WT under field conditions in different salmonid species.

Half-dried fish with improved properties

A study of consumer preferences for dried and half-dried fish products among respondents regularly visiting large retail sites in the city of Murmansk was conducted. It was found that more than two-thirds of respondents prefer to purchase high-quality dried and half-dried fish products; the weight of the purchased package of this product does not have a significant value. Sensory evaluation of extracts of 16 phytoproducts was carried out and the following highest-scoring ones were selected: chamomile flowers; golden mustache; linden flowers and sand immortelle flowers. Experiments of salting Atlantic salmon fillets and cod fillets in a weak saline solution with phytoextract for 12-96 hours were carried out; the ratio of fish, saline solution and aqueous extract of phytoproducts were 1:1:0.01. The most acceptable duration of weak finished salting is established not to be exceeding 48 hours. Experiments on drying the semi-finished product were carried out to establish the quality characteristics and the maximum duration of dehydration of the dried and half-dried fish product. Studies of the dehydrated product carried out every 4 hours by the sensory evaluations, the content and activity of water Aw established the most acceptable drying time, not exceeding 36 hours. Studies of dried fish products were carried out every 20 days according to organoleptic, chemical and microbiological parameters during the 80-day storage period. An acceptable storage period (shelf life) at the temperature of 0 - minus 5 ? of dried and half-dried vacuumed fish has been established to be of two months. Based on the results of the experiments, the technical specifications and technological instructions for the production of a new type of dried and half-dried formed fish with improved properties were developed.

The effects of pre-processing sanitation and modified atmosphere packaging on microbial growth in bulk packs of Atlantic salmon (Salmo salar) fillets

This research was to extend the shelf-life of fresh Atlantic salmon fillets when packaged in bulk food service modified atmosphere packaging trays with low gas to product volume ratios. When head-on-gutted Atlantic salmon were washed in Neutral electrolyzed water sanitizer prior to filleting, the microbial load on the skin of HOGs treated at 20 ppm and 100 ppm chlorine equivalents decreased by 3.5 log CFU/cm2 down to 2.0 and 1.5 log CFU/cm2, respectively. Further trials washed the HOGs with 100 ppm of NEW before filleting. They were then packed in a different product gas to product (G/P) volume ratios (0.4:1, 1:1 and 2:1) and stored at 0°C or 4°C up to 20 days. The combinations of sanitation pre-processing and high G/P ratio were most effective for controlling the microbial count to 4.5 log CFU/g when stored at 0°C compared to a microbial count of 7.2 log CFU/g for the unwashed fillets after 20 days under 4°C storage. Other variable combinations were between these levels. A combination of improved pre-processing sanitation and a low temperature can therefore raise the hurdles for microbial growth to extend the shelf-life of bulk packed fresh salmon fillets packed at high volumetric densities for storage and shipping efficiency.

The heritable landscape of near-infrared and Raman spectroscopic measurements to improve lipid content in Atlantic salmon fillets

BackgroundProduct quality and production efficiency of Atlantic salmon are, to a large extent, influenced by the deposition and depletion of lipid reserves. Fillet lipid content is a heritable trait and is unfavourably correlated with growth, thus genetic management of fillet lipid content is needed for sustained genetic progress in these two traits. The laboratory-based reference method for recording fillet lipid content is highly accurate and precise but, at the same time, expensive, time-consuming, and destructive. Here, we test the use of rapid and cheaper vibrational spectroscopy methods, namely near-infrared (NIR) and Raman spectroscopy both as individual phenotypes and phenotypic predictors of lipid content in Atlantic salmon.ResultsRemarkably, 827 of the 1500 individual Raman variables (i.e. Raman shifts) of the Raman spectrum were significantly heritable (heritability (h2) ranging from 0.15 to 0.65). Similarly, 407 of the 2696 NIR spectral landscape variables (i.e. wavelengths) were significantly heritable (h2 = 0.27–0.40). Both Raman and NIR spectral landscapes had significantly heritable regions, which are also informative in spectroscopic predictions of lipid content. Partial least square predicted lipid content using Raman and NIR spectra were highly concordant and highly genetically correlated with the lipid content values ({r}_{text{g}} = 0.91–0.98) obtained with the reference method using Lin’s concordance correlation coefficient (CCC = 0.63–0.90), and were significantly heritable ({h}^{2} = 0.52–0.67).ConclusionsBoth NIR and Raman spectral landscapes show substantial additive genetic variation and are highly genetically correlated with the reference method. These findings lay down the foundation for rapid spectroscopic measurement of lipid content in salmonid breeding programmes.

Effects of salting technology and smoking protocol on yield and quality of hot‐smoked Atlantic salmon ( Salmo salar L.)

This study determined the effects of different salting technologies (injection versus. dry-salting) and smoking protocols (smoked before, together with, or after the heating process) on the processing yield, and physiochemical- and microbiological quality of hot-smoked Atlantic salmon (Salmo salar L.) fillets throughout 24-days cold-storage (4°C). Obtained results showed injection-salted fillets to have higher yields, similar colorimetric- and textural properties, and contents of phenols as compared to those dry salted. The smoking protocol was moreover found to be the main discriminant affecting colorimetric- and textural properties of the different products. Hot-smoked fillets, independent of applied protocol, showed good microbiological stability that indicates physiochemical properties to be of highest importance when a protocol should be recommended. Consequently, due to highest yield, darker and less firm fillets it is recommended that hot-smoked Atlantic salmon should be processed by the injection of brine, followed by cold-smoking and thereafter heating of the product. Practical applications Among producers of hot-smoked Atlantic salmon, there is a large variation in processing protocols, and many smokehouses have their own in-house receipt that is reflected by the variation of products available on the market. In this study, several combinations of salting and smoking protocols have been evaluated related to quality and microbiological stability and are, therefore, highly relevant for the industry.

Do background levels of the pesticide pirimiphosmethyl in plant-based aquafeeds affect food safety of farmed Atlantic salmon?

ABSTRACT The substitution of fish oil and fishmeal with plant-based ingredients in commercial aquafeeds for Atlantic salmon, may introduce novel contaminants that have not previously been associated with farmed fish. The organophosphate pesticide pirimiphos-methyl (PM) is one of the novel contaminants that is most prevalent in commercial salmon feed. In this study, the feed-to-fillet transfer of dietary PM and its main metabolites was investigated in Atlantic salmon fillet. Based on the experimental determined PM and metabolite uptake, metabolisation, and elimination kinetics, a physiologically based toxicokinetic (PBTK) compartmental model was developed. Fish fed PM had a relatively low (~4%) PM retention and two main metabolites (2-DAMP and Desethyl-PM) were identified in liver, muscle, kidney and bile. The absence of more metabolised forms of 2-DAMP and Desethyl-PM in Atlantic salmon indicates different metabolism in cold-water fish compared to previous studies on ruminants. The model was used to simulate the long term (>1.5 years) feed-to-fillet transfer of PM + metabolite in Atlantic salmon under realistic farming conditions including seasonal fluctuations in feed intake, growth, and fat deposition in muscle tissue. The model predictions show that with the constant presence of the highest observed PM concentration in commercial salmon feed, fillet PM+ metabolite levels were approximately 5 nmol kg−1, with highest levels for the metabolite 2-DAMP. No EU maximum residue levels (MRL) for PM and its main metabolites exist in seafood to date, but the predicted levels were lower than the MRL for PM in swine of 32.7 nmol kg−1.

Variation in the nutritional composition of farmed Atlantic salmon (Salmo salar L.) fillets with emphasis on EPA and DHA contents

The increase in the global popularity and production of farmed Atlantic salmon (Salmo salar L.) has led to compositional changes in their feeds that can potentially diminish their nutritive value. Thus, the aim of the study was to compare the lipid, protein, fatty acid (omega-3) and mineral contents of salmon fillet portions available in the UK and estimate their contribution towards consumer dietary intake levels. Twenty pre-packaged fresh salmon fillets, encompassing all ranges (value, standard, premium and organic) and farmed origins (Scotland and Norway) were purchased from 10 main UK-wide retailers and analysed for their nutritional compositions. Lipid contents were between 11.2–16.3 % wet weight (ww), except the Retailer 10 value product which was significantly lower due to a high proportion of tail pieces. No difference in protein contents (17.5–20.2 % ww) were observed between fillets. However, fatty acid profiles showed marked variations between samples with marker fatty acids 18:1n-9 (24.3–42.0 %), 18:2n-6 (8.3–15.1 %) and 18:3n-3 (2.6–8.1 %) reflecting the differing levels of vegetable oil inclusion and eicosapentaenoic and docosahexaenoic acids (EPA + DHA, 5.6–16.6 %) indicating the level of marine oils included within salmon feeds. Consequently, EPA + DHA contents varied from 0.88 to 2.36 g EPA + DHA.130 g−1 flesh ww, equivalent to supplying 26–67 % of the recommended 3.5 g EPA + DHA weekly intake suggested for optimal cardiac health in adults. Similarly, selenium contents differed significantly between samples delivering between 13.9–55.5 % and 17.3–69.3 % of the 75 and 60 μg day−1 UK intake for males and females, respectively. Additionally, EPA + DHA and selenium contents were both affected by farmed origin, reflecting differences in production strategies of the two salmon producing nations. Overall, the study highlights the contrasting nutritional profiles of farmed salmon fillets available to consumers based on retailer requirements (healthy versus sustainable product) and how this can affect the recommended dietary intakes from a human nutrition perspective.

Investigation of Anisakis larvae in different products of ready-to-eat fish meat and imported frozen fish in Turkey

Globalization opens new market areas and affects food consumption habits, resulting in rapid and remarkable cultural change. Food habits such as consumption of raw fish meat have become popular, resulting in increased risk of emerging infectious diseases. Anisakis simplex sensu stricto (s.s) and A. pegreffii are the most common and important fish-borne zoonotic nematodes responsible for human anisakiasis, which occurs through the consumption of raw or undercooked fish as well as cooked fish due to their heat-stable allergens. Here, we investigated the prevalence, intensity, and abundance of Anisakis larvae in imported fish and ready-to-eat local fish products in Turkey. A total of 205 ready-to-eat fish products, 100 imported frozen Atlantic salmon (Salmo salar) fillets, and 100 imported frozen whole Atlantic mackerel (Scomber scombrus) were sampled from supermarkets, sushi restaurants, and fish markets. All samples were individually examined using a pepsin digestion technique. In total, 602 Anisakis type I larvae were recovered from 98/100 mackerel. No larvae were found in ready-to-eat products or frozen Atlantic salmon fillets. Overall, 8.8% of the larvae were found in the muscle tissue. The overall mean intensity and abundance of infection in mackerel were 6.14 and 6.02, respectively. The larvae were molecularly identified and their phylogenetic relationships with the relevant Anisakis sequences in GenBank were investigated. For this purpose, a subsample of randomly selected 100 Anisakis larvae were analyzed with PCR-RFLP of the ITS region. The larvae were identified as A. simplex (s.s.) (n = 87) and hybrids (n = 13). ITS and cox2 gene regions of all hybrids and randomly selected 50 A. simplex (s.s.) larvae were sequenced for species confirmation and phylogenetic analyses. No intraspecific nucleotide variation was found among the ITS sequences of either species. Seven and three haplotypes, respectively, were identified for A. simplex (s.s.) and hybrid species according to DNA polymorphism of the cox2 gene. Hybrids in our study clustered within the common A. simplex (s.s.) clade in the cox2 phylogenetic tree indicating the dominance of A. simplex (s.s) in the catching area of Atlantic mackerel. Consequently, our study indicates high occurrence of A. simplex (s.s.) larvae with an overall 98.0% prevalence in imported Atlantic mackerel, and highlights the importance of these fish as potential reservoirs for human allergic anisakiasis in Turkey and possibly in other countries.

Impact of traditional and mild oven cooking treatments on antioxidant compounds levels and oxidative status of Atlantic salmon (Salmo salar) fillets

Atlantic salmon is widely consumed in the diet. When salmon fillets are submitted to cooking treatments, the high temperature could promote lipid peroxidation with a consequent reduction in product nutritional quality. For this purpose, the impact of traditional (convection) and mild (steam- and sous-vide) oven cooking treatments were assessed on the level of some selected antioxidant and oxidative status of salmon. Fatty acid profile, tocopherols (α and γ), astaxanthin and coenzyme Q10 (CoQ10) levels, as well as markers for oxidative status [peroxide value (PV), thiobarbituric acid reactive substances (TBARS), percentage of oxidized CoQ10 on total CoQ10 amount] were determined in raw and cooked whole salmon fillets. As a result, the PV did not change as consequence of all treatments while TBARS level in raw sample (0.93 ± 0.16 μmol/g) was significantly higher than those found in all cooked ones, ranging from 0.43 ± 0.10 to 0.69 ± 0.17 μmol/g. Moreover, all oven treatments preserved ω3 PUFA and tocopherol fractions and led to a significant increase of CoQ10 availability, while solely the steam oven enhanced the availability of astaxanthin while reducing CoQ10 oxidative status in fillets.

Effect of chilling technologies on water holding properties and other quality parameters throughout the whole value chain: From whole fish to cold-smoked fillets of Atlantic salmon (Salmo salar)

The effect of different chilling technologies on water holding and quality parameters was investigated on Atlantic salmon throughout the entire value chain. Chilling technologies of whole fish before filleting, included superchilling(S) by refrigerated seawater (RSW) or ice (I), followed by chilling of fillets with liquid nitrogen (SS, IS) or ice (SI, II). Superchilling by shell-freezing with liquid nitrogen (IS and SS) caused increased drip loss throughout storage for both raw and smoked fillets. Whole salmon stored in RSW followed by ice storage (SI) had the least drip loss. Moreover, fish stored in RSW had lower H2S producing bacteria for raw fillets, lower blood spot counts and gaping after smoking. Therefore, this method is likely more feasible than storing whole fish in ice or shell-freezing of fillets. Water content, muscle pH and colour parameters were higher for raw than smoked fillets, while breaking force, firmness and water holding capacity were higher for smoked than raw fillets.

Changes in the Composition of Atlantic Salmon upon the Brown Seaweed (Saccharina latissima) Treatment.

This study shows the potential of improving the taste and shelf life of salmon by storing it in conjunction with sugar kelp. The influence of the addition of wet sugar kelp to Atlantic salmon fillet was assessed using a Nuclear Magnetic Resonance (NMR) metabolomics approach. Seaweed treatment caused significant changes in the polar and non-polar metabolic composition of salmon muscle upon its storage. The mutual diffusion of sugar kelp and salmon metabolites caused a significant decrease of the formation of the off-smelling compound trimethylamine and the biogenic amines, along with an increase of umami-related compounds (aspartate and succinic acid). Carotenoid composition of the seaweed-treated samples significantly differs from the reference samples. The amount of wet seaweeds used for the treatment and the time passed after the fish slaughter influence salmon quality parameters.

Accuracy of selection for omega-3 fatty acid content in Atlantic salmon fillets

The main aim of the current study was to compare the accuracy of selection for muscle content of fat and the health-promoting omega-3 fatty acids EPA and DHA in Atlantic salmon, by varying the sources of genetic information used in the estimation of breeding values. The following genetic information sources were compared: pedigree, SNP-chip markers and allele-specific expression markers.The results showed that differences between information sources were in general small, and different genetic information performed best for different traits. SNP-chip performed best for DHA, and pedigree performed best for EPA.Knowledge from gene expression analysis of a few individuals can be utilized to select a small panel of markers that perform relatively well. Genetic markers of allele-specific expression were able to capture a lot of genetic variation for DHA, but did not give significantly higher accuracies when combined with SNP-chip or pedigree information.The cross-validation accuracies for selection for DHA and EPA were moderate and offer possibilities for selection for these traits, especially if one extends the reference data set to a much bigger population, with more sibs per selection candidate.

A systematic review and analysis of long-term growth trials on the effect of diet on omega-3 fatty acid levels in the fillet tissue of post-smolt Atlantic salmon

Elucidating the specific effects of diet on the fatty acid composition in Atlantic salmon (Salmo salar), particularly health beneficial omega-3 long-chain polyunsaturated fatty acids (n-3 LC PUFA), remains an area of intense commercial interest given the increasing market restrictions placed on the supply of fishmeal and fish oil. The present study conducted a systematic review and subsequent analysis of published nutritional data from long-term growth trials using post-smolt Atlantic salmon to provide a summary of currently available information and to identify the most significant drivers of omega-3 levels in Atlantic salmon fillet tissue. Overall, there were relatively few studies which met the selection criteria and this had implications for further explanation of some results. Statistically significant regression models were generated for fillet DHA and fillet n-3 LC PUFA. Fish weight was a significant predictor in both models, and dietary 22:6n-3 (DHA) was an intuitive predictor of fillet DHA. Furthermore, dietary EPA and dietary 22:1 isomers were significant predictors of fillet n-3 LC PUFA.

Modeling Some Possible Handling Ways with Fish Raw Material in Home-Made Sushi Meal Preparation.

The aim of this work was to simulate selected ways of handling with raw fish after its purchase. The experiment was designed as three partial simulations: (a) trend in the biogenic amines formation in raw fish caused by breakage of cold chain during the transport after purchase, (b) the use of a handheld gastronomic unit as an alternative method of smoking fish with cold smoke in the household with regard to a possible increase in polycyclic aromatic hydrocarbon content, and (c) whether the cold smoked fish affects selected sensory parameters of nigiri sushi meal prepared by consumers. The material used in the research consisted of: yellowfin tuna (Thunnus albacares) sashimi fillets and the Atlantic salmon (Salmo salar) fillets with skin. The control (fresh/thawed tuna; without interrupting the cold chain) and experimental (fresh/thawed tuna; cold chain was interrupted by incubation at 35 °C/6 h) samples were stored at 2 ± 2 °C for 8 days and analyzed after 1st, 4th and 8th day of the cold storage. Histamine content was very low throughout the experiment, though one exception was found (thawed tuna without interrupting the cold chain: 272.05 ± 217.83 mg·kg−1/8th day). Tuna samples contained more PAH (4.22 µg·kg−1) than salmon samples (1.74 µg·kg−1). Alarming increases of benzo(a)anthracene (1.84 μg·k−1) and chrysene (1.10 μg·kg−1) contents in smoked tuna were detected.

GWAS identifies genetic variants associated with omega-3 fatty acid composition of Atlantic salmon fillets

The objective of this study was to identify genetic variants associated with long-chain omega-3 fatty acid content in Atlantic salmon muscle, in order to identify genes underlying the genetic variation in these traits, by performing a genome-wide association study.Fatty acid composition, including eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) content and the ratios DHA/DPA (docosapentaenoic acid) and DHA/ALA (α-linolenic acid) of skeletal muscle was determined in 642 Atlantic salmon individuals from the Salmobreed broodstock program. Further, a 57 K single-nucleotide polymorphism (SNP) array was used to genotype the 642 individuals to search for SNPs associated with skeletal muscle content of individual omega-3 fatty acids as well as ratios between fatty acids, using a mixed model approach. We identified markers showing a significant association with the ratio of DHA to DPA located on chromosome 19, close to the candidate gene elovl2, which is directly involved in the conversion of DPA to DHA. The results further suggested that genetic variation affecting fillet EPA and DHA content is present on Atlantic salmon chromosome 21, as the GWAS analysis of EPA, DHA and DHA/ALA ratio all pointed to this chromosome. No known genes of direct relevance to the omega-3 bioconversion pathway were found here. We discuss the relevance of other interesting genes related to lipid metabolism and health located in this region.

Characterization of Glycosaminoglycans in Gaping and Intact Connective Tissues of Farmed Atlantic Salmon (Salmo salar) Fillets by Mass Spectrometry.

In the Atlantic salmon (Salmo salar) aquaculture industry, gaping (the separation of muscle bundles from the connective tissue) is a major quality problem. This study characterized chondroitin sulfate (CS) and heparan sulfate (HS) in the connective tissue of intact and gaping salmon fillets from 30 salmon by mass spectrometry. Statistical difference was detected between gaping and intact tissues only when comparing pairwise samples from the same individual (n = 10). The gaping tissue had a lower content of monosulfated CS disaccharides (p = 0.027), and the relative distribution of CS disaccharides was significantly different (p < 0.05). The HS chains were short (average = 14.09, SD = 4.91), and the intact tissue seemed to have a more uniform HS chain structure compared to the gaping tissue. Time-series samples from the same individuals are recommended for future research to improve the understanding of reasons and implications of these differences.