Salmon Fillets Research Articles

Feed-to-Fillet Transfer of Selenite and Selenomethionine Additives to Plant-Based Feeds to Farmed Atlantic Salmon Fillet

This study investigated the transfer kinetics of dietary selenite and selenomethionine (SeMet) to the fillet of farmed Atlantic salmon (Salmo salar). The uptake and elimination rate constants of the two selenium (Se) forms were determined in Atlantic salmon fed either selenite- or SeMet-supplemented diets followed by a depuration period. The fillet half-life of selenite and SeMet was 779 ± 188 and 339 ± 103 days, respectively. The elimination and uptake rates were used in a simple one-compartmental kinetic model to predict levels in fillet based on long-term (whole production cycle) feeding with given dietary Se levels. Model predictions for Atlantic salmon fed plant-based feeds low in natural Se and supplemented with either 0.2 mg of selenite or SeMet kg-1 gave a predicted fillet level of 0.042 and 0.058 mg Se kg-1 wet weight, respectively. Based on these predictions and the European Food Safety Authority risk assessment of Se feed supplementation for food-producing terrestrial farm animals, the supplementation with 0.2 mg of selenite kg-1 would likely be safe for the most sensitive group of consumers (toddlers). However, supplementing feed to farm animals, including salmon, with 0.2 mg of SeMet kg-1 would give a higher (114%) Se intake than the safe upper intake limit for toddlers.

Valorization of Carob Fruit Residues for the Preparation of Novel Bi-Functional Polyphenolic Coating for Food Packaging Applications.

The food industry has become interested in the development of innovative biomaterials with antioxidant and antimicrobial properties. Although several biopolymers have been evaluated for food packaging, the use of polyphenolic coatings has been unexplored. The purpose of this work was to develop an antioxidant and antimicrobial coating for food packaging through the polymerization of carob phenolics. At first, the polyphenolic coatings were deposited in glass surfaces polymerizing different concentrations of carob extracts (2 and 4 mg mL−1) at three pH values (7, 8 and 9). Results demonstrated that the coating produced at pH 8 and at a concentration of 4 mg mL−1 had the most potent antioxidant and antimicrobial potential. Then, the coating was applied directly on the salmon fillet (coating) and on the plastic container (active packaging). Peroxide and thiobarbituric acid-reactive substances (TBARS) methods were used to measure the potency to inhibit lipid oxidation in salmon fillets. Furthermore, the anti-Listeria activity of coatings was also assessed. Results showed a significant decrease of lipid oxidation during cold storage of salmon fillets for both treatments; the superiority of applied coating directly on the salmon fillets was also highlighted. Regarding the antimicrobial potency, the polyphenolic coating depleted the growth of Listeria monocytogenes after 10 days storage; while the active packaging had no effect on Listeria monocytogenes. Overall, we describe the use of low-cost carob polyphenols as precursors for the formation of bifunctional coatings with promising applications in food packaging.

Growth Performance of Atlantic Salmon Smolts Fed Diets Containing Heterotrophic Algal Biomass as Replacement of Fish Oil

AbstractOne of the most widely cultured finfish in the world is the Atlantic Salmon Salmo salar, with over 2 million metric tons produced per year. Atlantic Salmon fillets are widely accepted by consumers as a source of long‐chain omega‐3 fatty acids, particularly eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). As feed producers shift from using marine ingredients to more terrestrial ingredients, producers need to monitor the fatty acid profiles of the fillets. Juvenile Atlantic Salmon (~280 g) were fed one of four diets during a 16‐week feeding trial. The four diets were formulated with increasing amounts (0, 5, 10, and 15%) of a DHA‐rich, whole dried algae (DHA = 20.3%) to reduce fish oil (12.7, 7.85, 3.00, and 0%, respectively). There were no significant differences in weight gain, feed efficiency, or the thermal growth coefficient. The proximate composition of the whole fish also did not vary due to dietary treatment. The amount of DHA in the fillets increased with increasing inclusion of the DHA‐rich algal biomass. The organoleptic properties (basic and aromatic tastes) also did not vary due to diet. The apparent digestibility coefficient was about 66%. Overall, including a heterotrophic algal biomass in the diets of Atlantic Salmon while reducing fish oil supported equivalent growth while maintaining levels of long‐chain omega‐3 fatty acids in the fillets.

Incorporation of pink pepper residue extract into chitosan film combined with a modified atmosphere packaging: Effects on the shelf life of salmon fillets.

Fresh salmon safety and quality is a major concern of consumers. In the current research, the effects of chitosan films incorporated with pink pepper residue extract and combined with modified atmosphere packaging (100% CO2) on quality properties of skinless salmon fillets during refrigerated storage (2 °C) were evaluated in the course of 28 days. Two different treatments as chitosan film (CF) and chitosan film incorporated with pink pepper residue extract (CFPP) and a control were compared. Salmon fillets were assessed for physicochemical (pH, WHC, TPA, Cie L*a*b*, TMA, TBA, value K), microbiological (mesophilic and psychrotrophic count, and lactic acid bacteria) and sensory properties. The results showed that CF and CFPP significantly reduced lipid oxidation relative to the control. Bacterial counts were significantly lower in CFPP, contributing to the significant reduction of trimethylamine. For sensory evaluation, CF and CFPP presented satisfactory results of off-odor and overall appearance. Despite being similar to the control, CFPP showed the lowest off-odor score. The results indicated that CFPP were more effective in maintaining the quality of salmon fillets during refrigerated storage.

Impact of fish growing conditions and cooking methods on selenium species in swordfish and salmon fillets

This study evaluates the effect of fish growing conditions (captured fisheries or aquaculture) and cooking methods (fried, oven-baked and smoked) on selenium species distribution in fish fillets (salmon and swordfish). Fillets from 10 individual fishes for each fish species were analyzed. Selenium speciation was examined using HPLC–ICP–MS. Selenium in fillet samples was mainly present as organic selenium (around 93% of selenium content). Selenomethionine (SeMet) and selenocystine (SeCys2) were the main species found in salmon, regardless of its growing conditions (farmed or wild). However, SeCys2 was found at a higher concentration in wild salmon fillets. Concerning swordfish, SeMet, SeCys2 and selenomethylselenocysteine (SeMetSeCys) were detected and quantified. New selenium species were not produced when fillets were cooked. However, differences in selenium species distribution were observed for some fishes and/or treatments. Baking led to a notable increase of SeMetSeCys in swordfish (68% of the total selenium), in comparison with the amount of SeMetSeCys found in raw fish (17% of total selenium), whereas a notable decrease of SeCys2 occurred when salmon was submitted to the different cooking techniques. In contrast, smoked salmon provided a selenium species distribution similar to that of raw farmed salmon.

Interaction between dietary fatty acids and genotype on immune response in Atlantic salmon (Salmo salar) after vaccination: A transcriptome study.

A pivotal matter to aquaculture is the sourcing of sustainable resources as ingredients to aquafeeds. Levels of plant delivered oils as source of fatty acids (FA) in aquafeeds have reached around 70% resulting in reduced levels of long-chain omega-3 polyunsaturated fatty acids (LC n-3 PUFA), such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), in salmon fillet composition. EPA and DHA can modulate inflammation and immune response, so it is crucial to understand how fish immune response is affected by low LC n-3 PUFA diet and if this diet can have a detrimental effect on vaccine response. Atlantic salmon (Salmo salar) can produce EPA/DHA from α-linolenic acid (ALA) and this endogenous capacity can be explored to develop families with higher tolerance to low LC n-3 PUFA diets. Here we analyze innate and adaptive immune response in Atlantic salmon to a commercial vaccine after being fed low levels of EPA and DHA, and we also compare three strains of salmon selected by their endogenous capacity of synthesizing LC- n-3 PUFA. A total of 2,890 differentially expressed genes (DEGs) were identified (p-value adjusted < 0.1) when comparing vaccinated fish against control non-vaccinated. Gene ontology (GO) and KEGG analysis with 442 up/downregulated genes revealed that most DEGs were both related to immune response as well as part of important immune related pathways, as “Toll-like receptor” and “Cytokine-Cytokine interaction”. Adaptive response was also addressed by measuring antigen specific IgM, and titers were significantly higher than in the pre-immune fish at 62 days post-immunization. However, diet and strain had no/little effect on vaccine-specific IgM or innate immune responses. Atlantic salmon therefore display robustness in its response to vaccination even when feed low levels of LC n-3 PUFA.

Meat and Fish Freshness Assessment by a Portable and Simplified Electronic Nose System (Mastersense).

The evaluation of meat and fish quality is crucial to ensure that products are safe and meet the consumers’ expectation. The present work aims at developing a new low-cost, portable, and simplified electronic nose system, named Mastersense, to assess meat and fish freshness. Four metal oxide semiconductor sensors were selected by principal component analysis and were inserted in an “ad hoc” designed measuring chamber. The Mastersense system was used to test beef and poultry slices, and plaice and salmon fillets during their shelf life at 4 °C, from the day of packaging and beyond the expiration date. The same samples were tested for Total Viable Count, and the microbial results were used to define freshness classes to develop classification models by the K-Nearest Neighbours’ algorithm and Partial Least Square–Discriminant Analysis. All the obtained models gave global sensitivity and specificity with prediction higher than 83.3% and 84.0%, respectively. Moreover, a McNemar’s test was performed to compare the prediction ability of the two classification algorithms, which resulted in comparable values (p > 0.05). Thus, the Mastersense prototype implemented with the K-Nearest Neighbours’ model is considered the most convenient strategy to assess meat and fish freshness.

Identifying Drivers of Genetically Modified Seafood Demand: Evidence from a Choice Experiment

The aquaculture industry has expanded to fill the gap between plateauing wild seafood supply and growing consumer seafood demand. The use of genetic modification (GM) technology has been proposed to address sustainability concerns associated with current aquaculture practices, but GM seafood has proved controversial among both industry stakeholders and producers, especially with forthcoming GM disclosure requirements for food products in the United States. We conduct a choice experiment eliciting willingness-to-pay for salmon fillets with varying characteristics, including GM technology and GM feed. We then develop a predictive model of consumer choice using LASSO (least absolute shrinkage and selection operator)-regularization applied to a mixed logit, incorporating risk perception, ambiguity preference, and other behavioral measures as potential predictors. Our findings show that health and environmental risk perceptions, confidence and concern about potential health and environmental risks, subjective knowledge, and ambiguity aversion in the domain of GM foods are all significant predictors of salmon fillet choice. These results have important implications for marketing of foods utilizing novel food technologies. In particular, people familiar with GM technology are more likely to be open to consuming GM seafood or GM-fed seafood, and effective information interventions for consumers will include details about health and environmental risks associated with GM seafood.

Effect of microwave cooking on foodborne pathogens in fish

Considering the popular use of microwave ovens to prepare foods, inhibitory effect of microwave cooking on foodborne pathogens was studied. Whiting and salmon blocks were inoculated either with E. coli O157:H7, Staphylococcus aureus or Listeria monocytogenes, then cooked in microwave oven to the internal temperatures of 50 and 70°C. Cooking of fish fillets to both internal temperatures resulted in approximately 4 log cfu/cm² reductions in E. coli O157:H7 population. After cooking to the internal temperatures of 50°C S. aureus counts reduced by 2.78 and 1.06 log cfu/cm² on whiting and salmon fillets, respectively. L. monocytogenes counts reduced by 1.70 and 0.14 log cfu/cm² on whiting and salmon fillets, respectively, cooked to 50°C. S. aureus and L. monocytogenes counts reduced below detectable level (2 log cfu/cm²) when cooked to 70°C. The results suggest that internal temperature should be higher than 70°C during microwave cooking to destroy completely these pathogens. PRACTICAL APPLICATIONS: This research shows that pathogens of Listeria monocytogenes, Staphylococcus aureus and E. coli O157: H7 cannot be completely inhibited by microwaving at 50 and 70°C (internal temperatures) in both fish species. The findings revealed that using a microwave oven to cook fish could be a problem regarding pathogen inactivation in terms of food safety and human health. The study may also help microwave oven producers and caterers to prepare the manufacturer's recommendations, and to determine CCPs in HACCP plans.

Evaluation of Salmon (Salmo salar) and Rainbow Trout (Oncorhynchus mykiss) pin bones using textural analysis and micro X-ray computational tomography

Industrially, common problems arise with the deboning pin bone process, where Atlantic Salmon (Salmo salar) and Rainbow Trout (Oncorhynchus mykiss) fillets, post rigor, are subjected to a pulling process to remove the pin bones from the fillet. This study measured the length of pin bones from two species of fish and two different industrial graded weights, and then used a texture analyser and µCT X-ray to measure the pulling force, break point and volume of the pin bones of both species of fish. Results showed that salmon pin bones required significantly higher pulling force to remove pin bones from the fish fillet when compared with Trout pin bones. Interestingly Trout pin bones were significantly longer and stronger than Salmon pin bones, but had significantly lower volume. This research has progressed the issues surrounding pin boning industrially, however, more studies are required in order to understand if these differences affect the overall deboning pin bone process.

Applications of extracts from skin and seed muscadine grape (Vitis rotundifoliaMichx.) waste on bacterial growth, autoxidation, and color in atlantic salmon (Salmo salarL.)

Phenolic compounds from grape waste have been used for researches as an alternative for food processing. In this context, the aim of this study was to evaluate the influence of skin and seed Muscadine grape extracts from viticulture waste over bacterial growth, antioxidant activity, and color on Atlantic salmon fillet. Total phenolic content and antioxidant capacity were evaluated by Folin–Ciocalteu and DPPH assays. Samples were analyzed by mesophilic count; pH, peroxide value and TBARS; and color parameters. It was observed that there is an influence over lag phase on bacterial growth. Primary oxidation was reduced (p < 0.05) on samples treated with seed extract. Treatments with skin extract suggested (p > 0.05) that astaxanthin was more effective on antioxidant activity. Samples treated with skin extract showed a significant difference (p < 0.05) on L*, a*, and b* values. Skin and seed extracts applicability showed to be an interesting alternative for food industries to synthetic antimicrobial and antioxidants. Practical applications Several thousand tons of waste are produced every year by viniculture, increasing the environmental situation. This study can contribute to reduce the problem and improve the fish quality for using immersion of polyphenol solution under fillet, which can be an interesting alternative for fishery industry.

Modelling of the feed-to-fillet transfer of ethoxyquin and one of its main metabolites, ethoxyquin dimer, to the fillet of farmed Atlantic salmon (Salmon salar L.)

ABSTRACTEthoxyquin (EQ) is an antioxidant supplemented to feed ingredients, mainly fish meal, which is currently under re-evaluation for use in the food production chain. EQ is partly metabolized into several metabolites of which the ethoxyquin dimer (EQDM) accumulates most in the farmed fish fillet. In this study, the feed-to-fillet transfer of dietary EQ and EQDM in Atlantic salmon fillet was investigated, and a physiologically based pharmacokinetic (PBPK-) two-compartmental model was developed, based on experimental determined EQ and EQDM uptake, metabolism, and elimination kinetics. The model was verified with an external data-set and used to simulate the long term (>1.5 years) EQ and EQDM feed-to fillet transfer in Atlantic salmon under realistic farming conditions such as the seasonal fluctuations in feed intake, growth, and fillet fat deposition. The model predictions showed that initial EQDM levels in juvenile fish are the driving factor in final levels found in food-producing animals, while for EQ the levels in feed, and seasonal variations were the driving factor for food EQ levels.

Spatial‐spectral analysis method using texture features combined with PCA for information extraction in hyperspectral images

AbstractThis work proposes a new method to treat spatial and spectral information interactively. The method extracts spatial features, ie, variogram, gray‐level co‐occurrence matrix (GLCM), histograms of oriented gradients (HOG), and local binary pattern (LBP) features, from each wavelength image of hypercube and principal component analysis (PCA) is applied on this spatial feature matrix to identify wavelength‐dependent variation in spatial patterns. Resultant image is obtained by projecting the score values to the original data. Three datasets, including a synthetic hyperspectral image (Dataset 1), a set of real hyperspectral images of salmon fillets (Dataset 2), and remote‐sensing images (Dataset 3), were utilized to evaluate the performance of the proposed method. Results from Dataset 1 showed that the spatial‐spectral methods had the potential of reducing baseline offset noise. Dataset 2 revealed that spatial‐spectral methods can alleviate noisy pixels with strong signal and reduce shadow effects. In addition, substantial improvements were obtained in case of classification between white stripe and red muscle pixels by using the HOG‐based approach with correct classification rate (CCR) of 0.97 compared with the models directly built from raw and standard normal variate (SNV) preprocessed spectra (CCR = 0.94). Samson image of Dataset 3 suggested the flexibility and effectiveness of the proposed method by improving CCR of 0.96 using conventional PCA on SNV pretreated spectra to 0.98 using GLCM‐based approach on SNV preprocessed spectra. Overall, experimental results demonstrated that the spatial‐spectral methods can improve the results found by using the spectral information alone because of the spatial information provided.

Polycyclic aromatic hydrocarbon contamination of Polish smoked fish: Assessment of dietary exposure

The aim of the study was to determine if the smoked fish being produced in Poland complies with the new, stricter limits set for BaP and PAH4. The effect of sample position in the smoking chamber was also studied. The margin of exposure (MoE) approach was used for assessing the risk of dietary exposure to PAHs from smoked fish products. The study material comprised of sprat, herring, mackerel, and salmon from a fish processing plant equipped with smoking chambers with external smoke generators. None of the smoked fish products studied exceeded the new, stricter limits set for BaP and PAH4. The MoE indicators far exceed the limit of 10,000 (values lower than this indicate a potential risk to consumer health). The sensory analysis identified significant differences among the products studied that indicate the high quality of cold‐smoked salmon fillets and the statistically significant lower quality of a smoked salmon abdominal parts. PRACTICAL APPLICATIONS: In 2011 and 2015, the European Commission amended Regulation No. 1881/2006, setting new maximum levels for polycyclic aromatic hydrocarbons in food products in order to protect consumer safety. The currently applicable limits are: for benzo(a)pyrene—2.0 μg/kg and for the sum of benzo(a)pyrene, benz(a)anthracene, benzo(b)fluoranthene, and chrysene—12.0 μg/kg in muscle meat of smoked fish and smoked fishery products with the exception of smoked, canned smoked sprat, smoked, and canned smoked Baltic herring ≤ 14 cm, where the limits are, respectively, 5.0 μg/kg and 30.0 μg/kg. The presented study was to determine if the sprat, herring, mackerel, and salmon from a fish processing plant equipped with smoking chambers with external smoke generators comply with the new, stricter limits set for BaP and PAH4 by Regulation No. 835/2011 and No. 2015/1125. The results showed that none of 54 smoked fish products that had been examined exceeded the new, stricter limits set for BaP and PAH4 and also that changes in PAH4 content depending on the position of the product in the smoking chamber were statistically insignificant, what is important information for processing plants. The sensory analysis indicated the high quality of cold‐smoked salmon fillets and the statistically significant lower quality of smoked salmon abdominal parts.

IDENTIFICATION OF CONTAMINATION OF SALMON MEAT BY DNA FROM BACTERIA OF THE PSEUDOMONAS FLUORESCENS GROUP IN THE IMPLEMENTATION OF THE DNA BARCODING OF PRODUCTS OF JAPANESE CUISINE

DNA barcoding as a tool for genetic certification and identification of taxonomic membership of organisms has recently become very popular. We have applied DNA barcoding method for taxonomic identification of fish ingredients (salmon, tuna, flying fish roe, shark) in product of Japanese cuisine. We have analyzed 27 samples from 6 retail outlets and 3 restaurants of the city of Voronezh. It was found that for products designated as containing “salmon” in all selected outlets were used as a fillet of Atlantic salmon (Salmo salar), which is considerably less valuable than Pacific salmon. Results of DNA barcoding showed that one of the samples of «salmon» was in fact, yellowfin tuna, whereas one sample of “tuna” was a fillet of Atlantic salmon. However in general, the “salmon” and “tuna” samples were substituted infrequently. Analysis of “flying fish roe” samples revealed that only one sample from 6 was really Fourwing flyingfish (Hirundichthys affinis). The remaining samples were identified as DNA of capelin (Mallotus villosus). By analyzing the “double” sequences in 2 samples, we have found that two samples of «flying fish roe» were mixtures of Fourwing flyingfish roe and capelin roe. A sample labeled “shark” was identified as Mozambique tilapia. This species is a freshwater fish. Bacterium Pseudomonas fluorescens was identified in one of the “salmon” samples. Analysis of “double” sequences of “salmon” samples revealed presence of P. fluorescens DNA. Analysis of salmon meat with the use of species-specific primers for this bacterium revealed contamination of all samples by P. fluorescens. This bacterium causes the disease in salmon and can be harmful to patients with compromised immune systems. Primers used for DNA barcoding were shown to have high homology to DNA of bacterial group P. fluorescens.

Identification of ethoxyquin and its transformation products in salmon after controlled dietary exposure via fish feed

Ethoxyquin (EQ) is an additive present in fish feed and its fate in fish should be carefully characterized due to food safety concerns regarding this compound. Therefore, the objective of this work was to identify the transformation products (TPs) of EQ in Atlantic salmon. Salmon in independent tanks were given feed containing ethoxyquin concentrations of 0.5 mg/kg, 119 mg/kg or 1173 mg/kg for 90 days. After the feeding trial, salmon fillets were extracted in acetonitrile and analyzed by liquid chromatography with traveling-wave ion mobility spectrometry coupled to high resolution mass spectrometry (UHPLC-TWIMS-QTOFMS). EQ was transferred from the feed to salmon fillets and 23 TPs were characterized, resulting from dimerization, oxygenation, cleavage, cleavage combined with oxygenation, cleavage combined with conjugation, and other uncategorized alterations. Moreover, EQ and some TPs were also detected in commercial salmon randomly sampled from different Norwegian fish farms. This study confirmed that the dimer 1,8′-EQDM was the main TP of EQ and, together with previous research, brought the overall number of characterized TPs to a total of 47.

Listeria monocytogenes survival in raw Atlantic salmon (Salmo salar) fillet under in vitro simulated gastrointestinal conditions by culture, qPCR and PMA-qPCR detection methods

Because the food matrix is considered as one of the significant factors in regulating colonization of microorganisms in the gastrointestinal tract, this study aimed to evaluate how Listeria monocytogenes survives in raw Atlantic salmon fillet under in vitro simulated gastrointestinal conditions steps. For in vitro gastrointestinal conditions, raw salmon fillet samples were spiked with two L. monocytogenes inoculum levels at 2 and 8 log CFU/g, respectively. L. monocytogenes enumeration was determined using culture-dependent, qPCR and PMA-PCR methods, and these results determined L. monocytogenes recovery rate. The PMA-qPCR method was the most efficient for L. monocytogenes enumeration, mainly after oesophagus-stomach and duodenum steps. The recovery rate was higher than 76%, while to the traditional method this value was lower than 23%. Overall, L. monocytogenes showed stability against the gastrointestinal conditions steps, once the recovery rate was higher than 75%. However, the raw salmon fillet did not contribute to L. monocytogenes stability under in vitro simulated gastrointestinal conditions. The results obtained contribute to understanding L. monocytogenes survival mechanism in a raw fishery product, predicting their behavior during gastrointestinal conditions.

Selective laser broiling of Atlantic salmon

Selective laser broiling is a novel food processing technique that utilizes a 2-axis mirror galvanometer system to direct laser power to cook raw food. Unlike conventional cooking processes, laser cooking benefits from the high spatial and temporal precision of power delivery. In this investigation, we use a trochoidal scanning pattern to optimize the cooking of Atlantic salmon (Salmo salar), which is used as a model food system. We vary geometry of the trochoidal cooking pattern (circle diameter, circle density, and period) as well as the heat flux (2.71 MW/m2 and 0.73 MW/m2) and power (2 W and 5 W) of the blue laser and measure the internal temperature and depth of heat penetration via color analysis. Heat generated by blue laser operating at 445 nm has a thermal penetration depth nearing 2 mm in salmon and provide sufficient protein denaturation for cooking thin food layers. We achieve food safe cooking temperatures (>62.8 °C) in the salmon fillets and desirable color and textural changes through the use of high speeds and repetitive exposure. Ultimately, the goal of this study is to explore laser cooking of meat with an eye to applications both in food printing as well as an augmentation of conventional oven cooking.

In Vitro Antithrombotic Properties of Salmon (Salmo salar) Phospholipids in a Novel Food-Grade Extract

Marine and salmon polar lipids (PLs) extracted by conventional extractions with non-food-grade solvents (CE-salmon-PLs) possess antithrombotic bioactivities against platelet-activating factor (PAF) and thrombin. Similar effects of food-grade-extracted (FGE) marine PLs have not yet been reported. In this study, food-grade solvents were used to extract PLs from Irish organic farmed salmon (Salmo salar) fillets (FGE-salmon-PLs), while their antithrombotic bioactivities were assessed in human platelets induced by platelet aggregation agonists (PAF/thrombin). FGE-salmon-PLs were further separated by thin layer chromatography (TLC) into lipid subclasses, and the antithrombotic bioactivities of each subclass were also assessed. LC-MS was utilized to elucidate the structure-activity relationships. FGE-salmon-PLs strongly inhibited PAF-induced platelet aggregation, while their relevant anti-thrombin effects were at least three times more potent than the previously reported activities of CE-salmon-PLs. TLC-derived lipid fractions corresponding to phosphatidylcholines (PC) and phosphatidylethanolamines (PE) were the most bioactive lipid subclasses obtained, especially against thrombin. Their LC-MS analysis elucidated that they are diacyl- or alkyl-acyl- PC and PE moieties baring ω3 polyunsaturated fatty acids (PUFA) at their sn-2 position, such as eicosapentaenoic acid (EPA) or docosahexaenoic acid (DHA). Our results concerning the potent antithrombotic effects of FGE-salmon-PLs against both PAF and thrombin pathways strongly suggest that such food-grade extracts are putative candidates for the development of novel cardioprotective supplements and nutraceuticals.

Nondestructive Identification of Salmon Adulteration with Water Based on Hyperspectral Data

For the identification of salmon adulteration with water injection, a nondestructive identification method based on hyperspectral images was proposed. The hyperspectral images of salmon fillets in visible and near-infrared ranges (390–1050 nm) were obtained with a system. The original hyperspectral data were processed through the principal-component analysis (PCA). According to the image quality and PCA parameters, a second principal-component (PC2) image was selected as the feature image, and the wavelengths corresponding to the local extremum values of feature image weighting coefficients were extracted as feature wavelengths, which were 454.9, 512.3, and 569.1 nm. On this basis, the color combined with spectra at feature wavelengths, texture combined with spectra at feature wavelengths, and color-texture combined with spectra at feature wavelengths were independently set as the input, for the modeling of salmon adulteration identification based on the self-organizing feature map (SOM) network. The distances between neighboring neurons and feature weights of the models were analyzed to realize the visualization of identification results. The results showed that the SOM-based model, with texture-color combined with fusion features of spectra at feature wavelengths as the input, was evaluated to possess the best performance and identification accuracy is as high as 96.7%.