Sea Bass Muscle Research Articles

Collaborative Effect of Matrix Metalloproteinases on Type I Collagen Degradation and Muscle Softening in Sea Bass (Lateolabrax japonicus) during Cold Storage.

Matrix metalloproteinases (MMPs) play critical roles in the degradation of collagens, while their mechanism remains unclear. In the present study, the involvement of matrix metalloproteinases (MMPs) in collagen degradation of sea bass muscle during cold storage was explored. Immunohistochemical staining results showed significant degradation of type I collagen in the connective tissue of muscle endomysium during cold storage, thus affecting the muscle structural integrity and quality. Western blot analysis revealed an increment in the α1 chain and a decrease in the β and γ chains of type I collagen. Immunofluorescence staining showed that MMP-2, MMP-9, and MMP-13 were distributed in the endomysium surrounding the muscle fibers. Additionally, the catalytic domains of MMP-2, MMP-9, and MMP-13 with biological activities were successfully expressed. The degradation trend of type I collagen by MMPs under 4 °C was similar to that of muscle collagen during cold storage, suggesting that the degradation of type I collagen was attributed to the cooperative action of the MMPs. In conclusion, our study elucidated that the MMPs-engaged degradation of type I collagen is quite possibly the leading cause of sea bass muscle softening during cold storage.

Lc-ms-based lipidomics analyses revealed changes in lipid profiles in Asian sea bass (Lates calcarifer) with dielectric barrier discharge (DBD) atmospheric plasma treatment

A comprehensive LC-MS-based lipidomics analysis of Asian sea bass (Lates calcarifer) muscle after dielectric barrier discharge (DBD) atmospheric plasma treatment was performed. Through the analysis, 1500 lipid species were detected, phosphatidylcholine (PC, 27.80%) was the most abundant lipid, followed by triglyceride (TG, 20.50%) and phosphatidylethanolamine (PE, 17.10%). Among them, 125 lipid species were detected and identified as differentially abundant lipids in Asian sea bass (ASB). PCA and OPLS-DA showed that ASB lipids changed significantly after DBD treatment. Moreover, glycerophospholipid metabolism was key metabolic pathways, as PC, PE, and lysophosphatidylcholine (LPC) were key lipid metabolites. The findings concerning fatty acids revealed that the saturated fatty acids (SFA) content of ASB after DBD treatment increased by 8.54%, while the content of monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA) decreased by 13.77% and 9.16%, respectively. Our study establishes a foundation for the lipid oxidation mechanism of ASB following DBD treatment.

Ultrasound improves the low-sodium salt curing of sea bass: Insights into the effects of ultrasound on texture, microstructure, and flavor characteristics

The purpose of this study was to evaluate the effects of ultrasonic pretreatment on the quality of cured sea bass. Compared to static marination, ultrasonication significantly increased the rate of NaCl transfer, reduced the hardness and chewiness of fish, and improved water retention. Microstructural observations revealed that the sea bass muscle fibers were severely fragmented, with their borders becoming increasingly blurred with increasing ultrasonic intensity. In addition, ultrasound-assisted marination significantly increased the degradation of proteins, total free amino acid levels, and relative levels of volatile flavor substances such as aldehydes and esters. Therefore, the use of an appropriate ultrasound treatment for the salt curing of fish has a positive effect on the textural and flavor characteristics of sea bass, with the most optimal approach being 300.W ultrasound treatment for 60 min. Overall, the results of this study provide technical evidence for improving the quality of lightly cured low-salt content seafood.

Exploring alternative marine lipid sources as substitutes for fish oil in Farmed Sea bass (Dicentrarchus labrax) and their influence on organoleptic, chemical, and nutritional properties during cold storage

This study evaluated the replacement of fish oil (sardine oil) by different combinations of alternative marine lipid ingredients as sources of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in European sea bass (Dicentrarchus labrax) throughout 14 days of ice storage. A practical diet (SARDINE) was used as a control, which included 9% sardine oil and 4.4% soybean oil, providing 2.3% of EPA + DHA. Two other experimental diets were formulated to achieve the same EPA + DHA values but completely devoid of soybean oil. In the ALGABLEND diet, 6.7% of salmon oil (salmon by-product) and 2% of algae biomass (Algaessence Feed™) partially replaced sardine oil. In the ALGAOIL diet, sardine oil was totally replaced with 10.1% salmon by-product oil and 3.3% algae oil (Veramaris®). All diets were equally well-accepted by European sea bass, resulting in similar growth performance, somatic indexes, and whole body composition. At the end of the trial, no significant differences were found in the EPA + DHA levels of fish muscle between dietary treatments, resulting in high values of EPA + DHA (> 0.62 g 100 g−1). Furthermore, replacing fish oil did not significantly affect the organoleptic and chemical properties of the fish samples. Parameters such as pH, water holding capacity, lipid oxidation, antioxidant capacity, color and texture presented similar values to those obtained for fish fed the SARDINE diet during the 14 days of storage in ice. In conclusion, these results show that combining algal oil (Veramaris®), algae blend (Algaessence Feed™) and salmon by-product oil can be a successful strategy for the fortification of European sea bass muscle in EPA and DHA while ensuring fish freshness, nutritional quality, and consumers’ health.

A strategy to link the changes in the quality traits of Japanese sea bass (Lateolabrax japonicus) muscle and proteins in its exudate during cold storage using mass spectrometry.

In this study, Japanese sea bass (Lateolabrax japonicus) was used as a model to link the changes in the quality traits of fish muscle during storage to the change of protein in muscle exudate. Matrix-assisted laser desorption time-of-flight mass spectrometry (MALDI-TOF MS) combined with variables importance in projection (VIP) analysis, and high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS), were applied to identify the proteins by analyzing the enzymatic hydrolysates of exudates of fish muscle. The link in the identified proteins to the change in the quality traits of fish muscle during storage was explored using pyramid diagrams. Nine proteins were identified from the exudate of Japanese sea bass muscle during 12 days of storage at 4 °C. Of these, four proteins, glyceraldehyde-3-phosphate dehydrogenase (GAPDH), heat shock protein 90 (HSP90), and peroxiredoxin 1 (PRX1), and beta-actin were found to be responsible for the changes in the quality traits of fish muscle. It is promising to correlate the changes in the quality traits of fish muscle and proteins in muscle exudate via MS-based protein identification and the construction of a relationship diagram to understand the mechanism of muscle change at the molecular level.

Immunity elicited by AMP-encoding plasmids fails to increase the protection of European sea bass against nodavirus

Antimicrobial peptides (AMPs) are a potent arm of the innate immune system that can directly kill pathogens and induce immunomodulation. In the marine aquaculture, European sea bass (Dicentrarchus labrax L.) is one of the most prosperous species but is highly susceptible to nodavirus (NNV), which produces high rates of mortality in larvae and juvenile stages. Thus, we aimed to evaluate whether AMPs exert immunomodulatory and/or NNV-preventive actions in sea bass. To do this, plasmids encoding the sea bass AMPs dicentracin (pDIC), beta-defensin (pDB1), hepcidin (pHAMP2) or NK-lysin (pNKL) were generated and intramuscularly injected into sea bass juveniles to evaluate their immunomodulatory and anti-NNV roles. Sea bass muscle transcribes the AMPs and produces an increase in their circulating levels, along with an increase of the antibacterial activity. Immune-related gene analysis revealed a great activation of the inflammatory response and the recruitment of neutrophilic granulocytes at the site of injection. However, AMP-encoding plasmids, namely pHAMP2, negatively affected to NNV disease by increasing fish mortality. In conclusion, plasmids encoding AMPs show immunostimulatory effects on European sea bass but do not improve the resistance to NNV.

Dietary Tenebrio molitor Larvae Meal Inclusion Exerts Tissue-Specific Effects on Cellular, Metabolic, and Antioxidant Status in European Sea Bass (Dicentrarchus labrax) and Gilthead Seabream (Sparus aurata).

The present study addresses the effects of dietary Tenebrio molitor (TM) larvae meal inclusion on cytoprotective, cell death pathways, antioxidant defence, and intermediate metabolism in the heart, muscle, and digestive tract of gilthead seabream (Sparus aurata) and European sea bass (Dicentrarchus labrax). Three experimental diets were formulated to contain 0%, 25%, or 50% inclusion TM levels. Heat Shock Proteins (HSPs) induction was apparent in both species' muscle at 50% inclusion. Conversely, p44/42 Mitogen-Activated Protein Kinase (MAPK) activation was increased (p < 0.05) in both species' muscle and digestive tract at 25% inclusion. Regarding the apoptotic machinery, TM inclusion exerted no influence on gilthead seabream, while suppression through autophagy may have occurred in the muscle. However, significant apoptosis (p < 0.05) was evident in European sea bass muscle and digestive tract. Both fish species' heart seemed to additionally rely on lipids compared to muscle and digestive tract. In contrast to gilthead seabream, European sea bass exhibited increased (p < 0.05) antioxidant activity at 50% TM inclusion. The present findings highlight the dietary derived induction of cellular responses in a species- and tissue-specific manner, whereas European sea bass appears to be more susceptible to TM inclusion.

Label-free proteomic analysis reveals freshness-related proteins in sea bass (Lateolabrax japonicus) fillets stored on ice

The advantages of epigallocatechin gallate incorporated in agar oligosaccharide treatment during post-mortem storage on ice for maintaining the quality and proteome stability of sea bass muscle was investigated using hardness, total volatile basic nitrogen, total viable counts, protein biochemical properties and label-free proteomic analysis. The results indicated that hardness value and sulfhydryl content of EGCG–AO-treated fish muscle were much higher than those of the samples immersed in sterile water. The total volatile basic nitrogen, total viable counts, and carbonyl content increased to 165.65%, 18.93%, and 42.37%, respectively after 8 days of storage. Proteomic analysis of muscle samples from control fillets on days 0 (CK0) and 8 (CK8), and EGCG–AO-treated fillets on day 8 (T8) revealed 708 different abundant proteins (DAPs). DAPs in CK8 vs. CK0 fillets were mainly structural proteins, metabolic enzymes, and proteins involved in protein turnover, and were closely related with freshness properties. Muscles from fillets in T8 showed delayed degradation of structural proteins, lower abundance of calpain and carbohydrate metabolic enzymes, and maintained higher levels of transcription and translation to maintain quality. Thus, EGCG–AO treatment is a possible method for maintaining freshness of sea bass fillets. Several DAPs are potential proteomic markers for monitoring fillet freshness.

Different lipid scenarios in three lean marine teleosts having different lipid storage patterns

This study investigated the lipid composition characteristics in turbot (Scophthalmus maximus), tiger puffer (Takifugu rubripes), and Japanese seabass (Lateolabrax japonicus), three important aquaculture species having different lipid storage patterns. All fish were fed the same diet for 9 weeks prior to analysis, in order to minimize the effects of their respective previous diets. Lipid concentration, fatty acid composition, and lipid metabolism-related biochemical parameters in various tissues of these three species analyzed. Gallbladder bile acid profile and muscle texture were also analyzed. Results of this study evidenced that turbot, tiger puffer, and Japanese seabass used subcutaneous adipose tissue, liver, and intraperitoneal adipose tissue as the predominant lipid storage site, respectively. Japanese seabass muscle had the highest contents of total lipid and triacylglycerol, and tiger puffer muscle had the lowest lipid content but the highest hardness. Low DHA/EPA ratio and high 18:0 and n-6 PUFA contents were the most distinctive characteristic of muscle fatty acid profile in Japanese seabass and tiger puffer, respectively. The analysis of cholesterol and gallbladder bile acid profile also provided basic information for lipid physiology in farmed fish having different lipid storage patterns. In conclusion, the lipid storage pattern in marine teleost probably largely determines the lipid composition characteristics.

Comprehensive identification of native medium-sized and short bioactive peptides in sea bass muscle

Native peptides from sea bass muscle were analyzed by two different approaches: medium-sized peptides by peptidomics analysis, whereas short peptides by suspect screening analysis employing an inclusion list of exact m/z values of all possible amino acid combinations (from 2 up to 4). The method was also extended to common post-translational modifications potentially interesting in food analysis, as well as non-proteolytic aminoacyl derivatives, which are well-known taste-active building blocks in pseudo-peptides. The medium-sized peptides were identified by de novo and combination of de novo and spectra matching to a protein sequence database, with up to 4077 peptides (2725 modified) identified by database search and 2665 peptides (223 modified) identified by de novo only; 102 short peptide sequences were identified (with 12 modified ones), and most of them had multiple reported bioactivities.The method can be extended to any peptide mixture, either endogenous or by protein hydrolysis, from other food matrices.

Tissue depletion of five antibiotic residues in farmed European seabass (Dicentrarchus labrax)

Concerns about antibiotic use led to stricter legislations and overall better practices in aquaculture production. However, depletion time periods in tissues vary greatly with different antimicrobials, fish species, or experimental setup. In the present work, five drugs (sulfadiazine (SDZ), trimethoprim (TRI), flumequine (FLU), oxolinic acid (OXO), and oxytetracycline (OTC)) were incorporated into medicated feed, and their retention in European seabass muscle tissues assessed. Juveniles were placed in 300 L tanks at 18 °C and were manually fed with medicated feeds for a 7 day period (two concentrations per antimicrobial, ranging from 6 to 220 mg kg−1, which were based on previous studies on the occurrence of these antimicrobials). Residues were analyzed through a multi-class quantification method (UHPLC-MS/MS). Data on residues concentration through time followed a one-compartment model, with TRI concentrations above the established Maximum Residue Level (MRL) throughout the experiment. Similarly, OTC concentrations at the highest dose were also above 100 μg kg−1 up to 14 days after the medication period. Results obtained for TRI may indicate the presence of a dose dependency for this antimicrobial. FLU concentrations in muscle samples were the lowest through time (Cday7 of 279.70 and 386.63 μg kg−1, for prophylactic and therapeutic treatments, respectively). Half-life values of 14.37, 10.87, 5.36, 7.20, and 27.22 h (prophylactic treatment), and 20.95, 8.41, 5.61, 11.22, and 17.99 h (therapeutic treatment), were determined for SDZ, TRI, FLU, OXO, and OTC, respectively.Withdrawal times of 0, 2, and 5 days were determined for FLU, OXO, and SDZ, but sampling times for OTC and TRI should be longer, since antimicrobial concentrations were above the MRL 14 days after the end of the feeding period with medicated feed. Therefore, special attention should be given since they are the most used antibiotics in aquaculture and European seabass plays a major part in human nutrition in the Mediterranean region.

Reduction of persistent and semi-persistent organic pollutants in fillets of farmed European seabass (Dicentrarchus labrax) fed low fish oil diets

Traditionally, a major part of aquaculture technology requires fish oil (FO) and fish meal (FM) to produce the aquafeed for farmed species. FO is the main source of persistent organic pollutants (POPs) in fish feed. In recent years, the use of vegetable-origin ingredients in fish feeds has been increasingly studied as an alternative to reduce the levels of these lipophilic pollutants in farmed species. The aim of this study was to evaluate the effect of the use of dietary vegetable oils in the farming of European sea bass (Dicentrarchus labrax) on the contents in persistent - polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) - and semi persistent pollutants - polycyclic aromatic hydrocarbons (PAHs) and polybrominated diphenyl ethers (BDEs) - of their edible parts. A total of 60 seabass muscle pools were obtained from fish farmed employing six experimental diets, which contained different percentages of FO (6 vs. 3%) and FM (20%, 10% and 5%). We did not observe differences in the contamination level of seabass muscle in relation to the percentage of FM in their diet. However, the fish farmed using feed which had lower levels of FO (3%) showed significantly lower muscle levels of ΣPCBs and carcinogenic PAHs (Σc-PAHs), with a reduction of 25.6% and 95.11% (respectively), as compared with those fished raised with feed with higher levels of FO (6%). Also much lower levels were found in OCPs such as sum of DDTs (30.88% of reduction), sum of chlordanes (42.85% of reduction), and sum of BDEs (48.16% of reduction) in those seabass fed with a lower percentage of FO. The results of this study indicate that the use of alternative feed ingredients that allow the employment of low percentage of FO in feeds help to reduce the load of several toxic pollutants in the fillets of European seabass.

Response to dietary carbohydrates in European seabass (Dicentrarchus labrax) muscle tissue as revealed by NMR-based metabolomics.

Feed optimization is a key step to the environmental and economic sustainability of aquaculture, especially for carnivorous species. Plant-derived ingredients can contribute to reduce costs and nitrogenous effluents while sparing wild fish stocks. However, the metabolic use of carbohydrates from vegetable sources by carnivorous fish is still not completely understood. We aimed to study the effects of diets with carbohydrates of different digestibilities, gelatinized starch (DS) and raw starch (RS), in the muscle metabolome of European seabass (Dicentrarchus labrax). We followed an NMR-metabolomics approach, using two sample preparation procedures, the intact muscle (HRMAS) and the aqueous muscle extracts (1H NMR), to compare the variations in muscle metabolome between the two diets. In muscle, multivariate analysis revealed similar metabolome shifts for DS and RS diets, when compared with the control diet. HRMAS of intact muscle, which included both hydrophobic and hydrophilic metabolites, showed increased lipid in DS-fed fish by univariate analysis. Regardless of the nature of the starch, increased glycine and phenylalanine, and decreased proline were observed when compared to the Ctr diet. Combined univariate analysis of intact muscle and aqueous extracts indicated specific diet related changes in lipid and amino acid metabolism, consistent with increased dietary carbohydrate supplementation. Due to differential sample processing, outputs differ in detail but provide complementary information. After tracing nutritional alterations by profiling fillet components, DS seems to be the most promising alternative to fishmeal-based diets in aquaculture. This approach should be reproducible for other farmed fish species and provide valuable information on nutritional and organoleptic properties of the final product.

Significance of metallothioneins in differential cadmium accumulation kinetics between two marine fish species.

Impacted marine environments lead to metal accumulation in edible marine fish, ultimately impairing human health. Nevertheless, metal accumulation is highly variable among marine fish species. In addition to ecological features, differences in bioaccumulation can be attributed to species-related physiological processes, which were investigated in two marine fish present in the Canary Current Large Marine Ecosystem (CCLME), where natural and anthropogenic metal exposure occurs. The European sea bass Dicentrarchus labrax and Senegalese sole Solea senegalensis were exposed for two months to two environmentally realistic dietary cadmium (Cd) doses before a depuration period. Organotropism (i.e., Cd repartition between organs) was studied in two storage compartments (the liver and muscle) and in an excretion vector (bile). To better understand the importance of physiological factors, the significance of hepatic metallothionein (MT) concentrations in accumulation and elimination kinetics in the two species was explored. Accumulation was faster in the sea bass muscle and liver, as inferred by earlier Cd increase and a higher accumulation rate. The elimination efficiency was also higher in the sea bass liver compared to sole, as highlighted by greater biliary excretion. In the liver, no induction of MT synthesis was attributed to metal exposure, challenging the relevance of using MT concentration as a biomarker of metal contamination. However, the basal MT pools were always greater in the liver of sea bass than in sole. This species-specific characteristic might have enhanced Cd biliary elimination and relocation to other organs such as muscle through the formation of more Cd/MT complexes. Thus, MT basal concentrations seem to play a key role in the variability observed in terms of metal concentrations in marine fish species.

Rapid Confirmatory Method for the Determination of Danofloxacin and N-Desmethyl Danofloxacin in European Seabass by UPLC-PDA

Background: Danofloxacin is a synthetic antibacterial agent with broad spectrum antibacterial and antimycoplasmal activity which is widely used in aquaculture. Methods: A UPLC (Ultra Performance Liquid Chromatography) method was developed and validated for the determination of danofloxacin (Dano) and its major metabolite N-desmethyl danofloxacin (Ndesmethyl Dano) in muscle plus skin tissue of European seabass (Dicentrarchus labrax) for the first time. For the separation an analytical column UPLC BEH C18 2.1 × 5 mm (1.7 µm) was used with an isocratic mobile phase consisting of MeOH-water acidified with formic acid (0.01%) (18:82; v/v) and flow rate of 0.3 mL/min within 5.5 min. The detection was performed at 275 nm using a photodiode array detector for both compounds. Examined fluoroquinolones were isolated from seabass muscle and skin tissue by extraction with acidic ACN and further purification with the QuEChERS methodology. Results: Recovery rates from muscle and skin tissue ranged between 90.2 and 101.2% for both compounds. The detection limit of the method was estimated at 13.73 µg/kg for Dano, 18.32 µg/kg for Ndesmethyl Dano, while the limits of quantification were 41.62 and 55.52 µg/kg, respectively. The developed method was fully validated in terms of selectivity, linearity, accuracy, precision, stability and sensitivity according to the European Union Decision 2002/657/EC. Conclusion: The new developed and validated method can be readily applied to aqua cultured fish after dietary administration of danofloxacin. Keywords: Danofloxacin, metabolite, fish, seabass, residue analysis, QuEChERS, UPLC-PDA.

Spectroscopic analyses and genotoxicity of dioxins in the aquatic environment of Alexandria

Dioxins have global concerns because of the bioaccumulation tendency and persistency in the environment. Water, seabream Pagrus auratus and seabass Dicentrarchus labrax samples were collected from Abu Qir, Alexandria to evaluate the concentration of dioxin. Fourier Transform Infrared Spectrometer (FTIR) and molecular modeling was applied for elucidating the molecular structure of fish samples. Furthermore, HPLC with UV detection was used to determine the concentration of dioxins (2,8-dichloro dibenzo-p-dioxin). RT-PCR assay was conducted to verify the expression of some immune genes in the fish species as a result of water pollution. The average detected concentrations varied from 0.2 to 1.3μg/l. Gene expression revealed that MHC class 1 and C3 were highly upregulated in liver and muscle of seabass and seabream while T2BP was highly regulated in seabass liver and seabream muscle and seabass muscle for transferrin, FTIR and molecular modeling indicate that dioxin finds its way to fish protein.

Effects of fasting on the activities and mRNA expression levels of lipoprotein lipase (LPL), hormone-sensitive lipase (HSL) and fatty acid synthetase (FAS) in spotted seabass Lateolabrax maculatus.

To investigate the effects of fasting on lipid metabolism in spotted seabass muscle and liver tissues, we analyzed mRNA levels and enzyme activities of lipoprotein lipase (LPL), hormone-sensitive lipase (HSL) and fatty acid synthetase (FAS), and the relationship among fat content, mRNA level, and enzyme activity during fasting of 35days. The results showed that expressions of all the three genes were ubiquitous. During the fasting experiment, the hepatosomatic index (HSI) and fat content of muscle and liver tissues significantly decreased before 5days of fasting (P < 0.05). mRNA levels of LPL increased significantly after 5days of fasting in liver and 7days in muscle. Abundance of HSL transcripts increased significantly after 14days of fasting in both muscle and liver. The activities of LPL and HSL presented a trend that increased firstly, decreased subsequently, and then raised again with the prolonged fasting experiment (P < 0.05). However, activities and mRNA levels of FAS decreased significantly after 1day of fasting in both muscle and liver. Moreover, activities and mRNA levels of FAS showed a moderate correlation in muscle. These results suggested that FAS had a sooner response to fasting than LPL and HSL in both muscle and liver tissues. LPL and HSL played important roles in lipolysis mainly by increasing enzyme activities in the early stage of fasting and mRNA levels in the later stage of fasting in both muscle and liver. Our results also provided useful information on regulating muscle fat content by fasting.

Seasonal Changes in Rigor Development and Flesh Texture of Wild Japanese Sea Bass (Lateolabrax japonicus)

ABSTRACTThe season for finding the firmest sashimi made from wild Japanese sea bass was investigated. Flesh rigor tension and contraction were measured by a “new” device with isometric (muscle length kept constant) and isotonic (balance beam moves freely) transducers. Both flesh rigor tension and contraction peaks appeared at the same postmortem times, with attainment of ultimate pH and adenosine triphosphate/inosine monophosphate ratio in four seasons. Seasonal seawater temperature correlated negatively to seasonal maximum rigor contraction and positively to seasonal flesh breaking strength at 72 h postmortem. After rigor peak tension attainment, the tension relaxation was much lower than that of other wild fish species, especially in summer. The sea bass muscle resisted structure disruption in rigor isometric tension generation. Wild sea bass sashimi was firmest in breaking strength in summer.

The effects of storage on quality and nutritional aspects of farmed and wild sea bass (Dicentrachus labrax) muscle: In vitro oils digestibility evaluation

Nowadays, public awareness is in increase for the healthy and nutritive products especially fisheries products, which are commonly consumed by people as food or as oil fish supplement for therapeutic purpose. We provide new fish oil product results to assist industry in Tunisia and Mediterranean countries and, ultimately, consumers in understanding the high product quality. The present study deals with the changes of nutritional quality and properties of wild and farmed sea bass oil during storage at −20°C for 45days. Fatty acid (FA) composition, total volatile basic nitrogen, lipid damage indices and organoleptic characteristics of fish oil were determined. Regarding their nutritional quality, farmed sea bass was found to have a higher content of polyunsaturated FA and lower of saturated and MUFA. Among PUFAs, n-3 FA were predominant in wild species, whereas n-6 FA were more abundant in cultured one. Over storage, Peroxide and TVB-N values increases, however, PUFAs and lipid damage values were slightly reduced in both species after 45days of freezing. Therefore, it can be recommended to store sea bass products at −20°C to gain longer storage life. The lipid health indexes and the predominance of PUFAs acids in both studied fish could meet people’s needs. Interestingly, a higher stability of polyene index and carotenoids were observed during the storage at −20°C, which allows higher oils stability. In vitro digestion model revealed that sea bass oil was considerably hydrolyzed by pancreatic lipase suggesting this emulsion system as an excellent promise in delivering bioactive lipids into functional foods, which led to the increased consumer demand for n-3 FA oils.

Proteomic profiling of sea bass muscle by two-dimensional gel electrophoresis and tandem mass spectrometry

In this study, the proteome profile of European sea bass (Dicentrarchus labrax) muscle was analyzed using two-dimensional electrophoresis (2-DE) and tandem mass spectrometry with the aim of providing a more detailed characterization of its specific protein expression profile. A highly populated and well-resolved 2-DE map of the sea bass muscle tissue was generated, and the corresponding protein identity was provided for a total of 49 abundant protein spots. Upon Ingenuity Pathway Analysis, the proteins mapped in the sea bass muscle profile were mostly related to glycolysis and to the muscle myofibril structure, together with other biological activities crucial to fish muscle metabolism and contraction, and therefore to fish locomotor performance. The data presented in this work provide important and novel information on the sea bass muscle tissue-specific protein expression, which can be useful for future studies aimed to improve seafood traceability, food safety/risk management and authentication analysis. This work is also important for understanding the proteome map of the sea bass toward establishing the animal as a potential model for muscular studies.