Sea Bream Fillets Research Articles

Genetic parameters of fillet fatty acids and fat deposition in gilthead seabream (Sparus aurata) using the novel 30 k Medfish SNP array

Lipid-related traits are important candidates for a breeding goal for gilthead seabream, because they affect both fish and human health, as well as production efficiency. However, to date there have been very few estimates of genetic parameters for these traits, and the genetic relationship between fatty acids and other important traits have never been reported for gilthead seabream. Therefore, the aim of this study was to estimate genomic heritability and genetic relationships of fat deposition traits and individual muscle fatty acids in a commercial population of gilthead seabream using the novel ~30 k MedFish SNP array.In total 967 gilthead seabream fed with a commercial feed were genotyped with the MedFish SNP chip which included ~30 K informative markers for this species. On average, the fish weighed 372 g. The mean content of eicosapentaenoic acid (EPA) + docosahexaenoic acid (DHA) was 822 mg per 100 g fillet. The heritability of muscle fat, viscera weight and percentage viscera were in the range of 0.34–0.46. The genetic correlation of body weight with muscle fat was 0.12, indicating that genetic variation in muscle fat is largely independent of the weight of the fish. The heritability of the product of endogenous fatty acid synthesis (n = 240), palmitoleic acid (16:1n-7), was high (0.43). The estimated heritability of EPA (%) and DHA (%) was 0.39 and 0.33, respectively. Both EPA and DHA had low, non-significant genetic correlations with body weight, and DHA had a negative genetic correlation with muscle fat (−0.53).It is possible to increase EPA and DHA content in gilthead seabream fillets by selective breeding. The high heritability of 16:1n-7, a marker of de novo lipogenesis, suggests that there is a strong genetic component to this metabolic pathway in gilthead seabream. Muscle fat deposition and body weight seem to be independent traits, and selective breeding for faster growth is not likely to influence the proportional content of EPA and DHA.

Effect of the dietary supplementation based on essential oils on the quality of gilthead seabream

The effectiveness of using essential oils against fish parasites and pathogenic bacteria as environmentally friendly phytotherapeutic agents in the aquaculture industry is demonstrated. A commercial additive composed of garlic essential oil, thymol and carvacrol (AROTEC-G®) was added to a diet for gilthead seabream (Sparus aurata) as a protection strategy against Sparicotyle chrysophrii. The intense aromatic properties of these essential oils might lead to the need of a suppression time to reverse possible changes in the organoleptic quality of the fish. Two experimental groups were set up: an experimental group fed a commercial feed supplemented with AROTEC-G® (diet A) during the first 4 weeks of the nutritional assay, and after which the treatment was suspended for 14, 21 and 28 days after a first sampling performed (day 0); and a control group, fed the same basal diet without AROTEC-G® supplementation (diet C). A physicochemical evaluation measured the pH, colour and texture, and a descriptive quantitative sensory analysis (QDA) was carried out using a trained panel for gilthead seabream fillets. Overall, the findings showed that the use of dietary essential oils did not result in significant sensory differences after day 0 of the study, although slight differences were observed in some of the physicochemical parameters analysed.

Development of edible composite film based on chitosan nanoparticles and their application in packaging of fresh red sea bream fillets

This research was conducted to assess the structure, mechanical, barrier and optical properties of three edible composite films based on chitosan nanoparticles. Films containing cinnamon-perilla essential oil (C-PEO) Pickering nanoemulsion had denser structure and better mechanical properties. In addition, films with anthocyanidins exhibited enhanced antioxidant activity. The results showed that both Pickering nanoemulsion and anthocyanidins could improve some properties of edible composite film based on chitosan nanoparticles. Finally, preservation experiments were carried out. Analysis of storage quality indices (sensory evaluation, microbiological analyses, pH, total volatile basic nitrogen, thiobarbituric acid values, color and texture) revealed the shelf life of fillets wrapped in three kinds of composite film was extended to 6–8 days. The preservation effect of plant essential oil compound anthocyanidin edible film for fillet was the best and anthocyanidins compound chitosan nanoparticles edible film was the best in appearance of protection. • Three novel chitosan nanoparticles films were prepared and characterized. • Physical properties of the film improved with adding Pickering nano-emulsion. • The effect of three kinds of edible film on the preservation of fresh fillets. • Composite film delayed lipid oxidation and proteolysis in fresh fillets.

Fabrication and characterization of zein nanofibers integrated with gold nanospheres

The synthesis, characterization, and coating effect of zein nanofibers integrated with gold nanospheres were studied. Zein solution including ethanol/liquid gold nanospheres (80/20 v/v) was prepared to produce complex nanofibers. Dielectric constant (ε′), dielectric loss factor (ε′′), and loss tangent (ε′′/ε′) values of feed solutions were evaluated at 300 and 3000 MHz, and electrical conductivity was measured (808.67 ± 2.082 μs/cm). SEM image showed a bead free structure of the gold-zein complex. Zeta potential and DLS measurements (translational diffusion coefficient, hydrodynamic radii, polydispersity index, major axis) were done by dispersing nanofibers in ethanol or water. The stability of nanofiber dispersed in ethanol was higher (+41.73 mV) compared to that of dispersed in water (+5.1 mV). Molecular characterization by FTIR confirmed the formation of the zein-gold complex through a nitrogen-gold coordination bond and electrostatic interactions. The gold-zein nanofibers coating in sea bream fillets reduced 17.8% of total mesophilic bacteria (TMAB) compared to the uncoated group (p < 0.05) after 8 days of observation. The highest changes in ε′ for uncoated (57.65%) and coated samples (14.84%) during storage showed the positive impact of nanofiber treatment. These results showed that zein nanofibers with gold nanospheres could be potentially used as antimicrobial layer for food products.

Effect of dietary black soldier fly larvae meal on fatty acid composition of lipids and sn-2 position of triglycerides of marketable size gilthead sea bream fillets

Insects are an alternative protein source recently adopted in aquacultured carnivorous species. However, the replacement of marine ingredients with insect meal might cut down the n−3 polyunsaturated fatty acid (PUFA) of fish fillet, a fraction of great interest for human nutrition. Recently, it has been shown that different animal species and the human species better absorb the dietary fatty acids esterified in the sn-2 position of the triglyceride (TG) than those contained in the sn-1 and sn-3 positions. Hence, the present paper aimed to evaluate in which extent replacing fishmeal with insect meal could alter not only the fillet fatty acid (FA) profile, but even the FA distribution inside the TGs. Specifically, three-hundred and sixty gilthead sea bream (Sparus aurata L.) were randomly divided into four groups with three replicates each. The fish were fed for 120 days four isoenergetic, isolipidic and isoproteic diets where fishmeal was substituted by Hermetia illucens (HI) larvae meal. The inclusion levels were 0% (HI0), 9.2% (HI9), 18.4% (HI18) and 27.6% (HI27), corresponding to 0, 25, 50 and 75% of fishmeal substitution, respectively. At the end of the trial, 10 fish per group were analyzed for marketable traits, fillet color values and lipid composition. Dietary intervention did not affect any of the considered marketable traits and the fillet color. Major changes were observed in the FA profile of the fillet lipids. The fillets from fish fed HI18 and HI27 contained the highest amount of saturated fatty acids while their n-3 PUFA were significantly reduced in comparison with HI0 and HI9. Analogous variations were observed in the FA composition of the TG fraction. On the contrary, dietary HI did not reduce the overall n-3 PUFA positioned in the sn-2 of TG, nor eicosapentaenoic acid (EPA) percentage. In conclusion, dietary HI inclusion did not substantially modify the presence of important fatty acids for human nutrition (i.e., EPA and DHA) in the sn-2 position of the fillet triglycerides, increasing the chances to be better assimilated and absorbed by humans.

Classification of sea bream (Sparus aurata) fillets subjected to freeze-thaw cycles by using front-face fluorescence spectroscopy

The most common frauds carried out in different points of fish and fish product supply chain concern the selling of freeze-thaw fish as fresh fish. Moreover, fluctuation of temperature during the storage process, transportation, and sale modified the fish quality and increased the frozen-thawed cycles. In this study, front face fluorescence spectroscopy (FFFS) was used to determine the effect of freeze-thaw cycles on the quality of sea bream fillets. The application of factorial discriminant analysis (FDA) to the concatenated fluorescence spectra allowed to distinguish clearly between the numbers of freeze-thaw cycles applied to sea bream fillets since correct classification rate amounting to 91.67% was observed, regardless of the initial raw quality. This could be explained by changes in the tertiary structure of tryptophan and the oxidation state of NADH. The obtained result was confirmed following the application of partial least square regression (PLSR) since an excellent prediction of the number of freeze-thaw cycles was obtained (R 2 = 0.99; RPD = 7.13). Therefore, FFFS could be used as a rapid screening technique to detect with high accuracy between fresh, once and twice freeze-thaw sea bream fillets. • Fluorescence spectroscopy allowed the classification of sea bream fillets based on the number of freeze-thaw cycles. • Factorial discriminant analysis allowed fillets discrimination according to freeze-thaw cycles. • High predictive accuracy of freeze-thaw cycles was obtained by partial least square regression. • Fluorescence spectroscopy could be used for differentiating sea bream fillets subjected to freeze-thaw cycles.

Marinated Sea Bream Fillets Enriched with Lactiplantibacillus plantarum and Bifidobacterium animalis subsp. lactis: Brine Optimization and Product Design.

This study aimed to design marinated sea bream fillets, inoculated with either Lactiplantibacillus plantarum (strains 11, 68, 69) or Bifidobacterium animalis subsp. lactis DSM 10140. In the first step, the optimization of brine composition was performed through a centroid; the factors of the design were citric acid, vinegar, and salt. As a result of optimization, the optimal composition of brine was set to 0.75% citric acid, 55% vinegar, and 3% NaCl. In the second step, sea bream fillets were inoculated with L. plantarum strain 69 and B. animalis subsp. lactis, marinated and then packed in a conditioning solution (oil or diluted brine); the samples were stored at 4 °C for 21 days. The viability of the strains and sensory scores were assessed. The bacteria retained a high viability throughout storage (21 days); however, the sensory scores were at their highest level for 4 days. In particular, sensory assessment suggested a preference for a conditioning solution with oil, rather than with a diluted brine. In addition, a slightly higher preference was found for B. animalis subsp. lactis.

Quality and Shelf-Life Modeling of Frozen Fish at Constant and Variable Temperature Conditions.

The objective of this study was the investigation of the effect of variable conditions on quality parameters and the shelf life of fish during frozen storage. Three different fish products were tested, i.e., gilthead sea bream (Sparus aurata) fillets, sea bass (Dicentrarchus labrax) fillets, and yellowfin tuna (Thunnus albacares) slices stored in the range of −5 to −15 °C. The kinetic modeling of different shelf-life indices was conducted. Sensory scoring of frozen fish showed high correlation with color (L-value) and total volatile basic nitrogen (TVBN). The temperature dependence of the rates of quality degradation was expressed via the activation energy values, calculated via the Arrhenius equation, and ranged, for the tested quality indices, between 49 and 84 kJ/mol. The estimated kinetic parameters were validated at dynamic conditions and their applicability in real conditions was established, allowing for their practical application as tools for cold chain management.

Food container employing a cold atmospheric plasma source for prolonged preservation of plant and animal origin food products

Cold Atmospheric Plasma is a non-thermal processing technology with great potential for application to food products as it can effectively reduce the microbial load, leading to substantial shelf-life extension. Herein, we present an easy-to-build and cost-effective Surface Dielectric Barrier Discharge (SDBD) plasma source adjusted to the plastic lid of a common commercial food container made of transparent glass. Implementation and evaluation of plasma treatment in real perishable food products such as sea bream fillets, fresh-cut rocket salads and fresh whole strawberries showed that such device might be efficiently used in-storage for the extension of their shelf-life.•Easy-to-build and cost-effective SDBD plasma source adjusted in a food container for generation of antimicrobial RONS in proximity to treated food product•Treatment of perishable food products by reducing their initial microbial load•In-storage treatment efficient for perishable food products shelf-life extension

Comparative Study on the Effect of Cold Atmospheric Plasma, Ozonation, Pulsed Electromagnetic Fields and High-Pressure Technologies on Sea Bream Fillet Quality Indices and Shelf Life

A comparative study on the effect of nonthermal processing using cold atmospheric plasma (CAP), ozonation (OZ), pulsed electromagnetic fields (PEMF) and high pressure (HP) on the quality and shelf life of fresh sea bream fillets was conducted. The aim was the selection of the optimum nonthermal processing technology for minimum effect on the fish quality and maximum shelf-life extension, based on pre-selected processing conditions for each technology. Air plasma was generated using a surface dielectric barrier discharge (SDBD) source (3 kV, 45 kHz) applied for 15 min at 25 °C. PEMF (80 J/pulsed energy, 12.5 mT, 3 Hz) and OZ (1.3 mM of aqueous ozone, flow rate 640 ppm) were also applied for 15 min at 25 °C. HP treatment at 300 MPa/5 min at 25 °C was studied. Processed and unprocessed fillets were stored at 4 °C for 22 days. The fish fillets were analysed for their microbial load, pH, texture, colour, lipid oxidation, and sensorial characteristics, during storage. The shelf life of the product was extended by 4 and 2.5 days after HP and CAP processing, respectively. HP was more effective on the microbial load reduction compared to the other processes; nevertheless, colour and texture alteration of the fish fillets was observed. CAP processing decreased the initial total microbial load by 1.03 logCFU/g, while also resulted to reduced intension of the fish odour. PEMF and OZ affected slightly the quality indices nevertheless found to be less effective on the microbial load reduction with only 1 day shelf-life extension of the fillets.

Dietary Saccharina japonica is a natural and effective tool to fortify marine teleost black sea bream fillets with iodine: effects on growth, flesh quality, and serum thyroid hormones

In the present study the effects of dietary Saccharina japonica on growth performance, flesh quality traits, and serum thyroid hormones (tetraiodothyronine (T4) and triiodothyronine (T3)) of juvenile black sea bream, Acanthopagrus schlegelii, were investigated. Seven diets containing graded levels of S. japonica (0, 0.1, 0.2, 1.2, 2.5, 5, and 10%) were formulated. Each diet was randomly assigned to sex replicate groups of 40 fish. After a 90-day feeding trial, the best growth performance was achieved in fish fed with the 2.5% S. japonica diet, with significantly higher weight gain rate (WGR) and lower feed coefficient (FC) than those fed with the other diets (P 0.05) on proximate composition of the whole body and the muscle. However, the content of n-6PUFA, n-3PUFA, and LC-PUFA in the muscle was significantly increased with the increasing level of dietary S. japonica. No differences in the flesh texture, cooked meat rate and water holding capacity were found among fish fed with different diets. It was further demonstrated that dietary S. japonica significantly fortify fillets with iodine (from 0.11 to 1.05 mg kg−1DM) and increased serum T4 and T3 levels. These results showed that the inclusion of up to 2.5% of S. japonica meal in diets could be beneficial to aquaculture of juvenile black sea bream, while higher inclusion levels resulted in significantly smaller fish. Moreover, the content of flesh iodine content quintupled in fish fed 2.5% up to 2.5%, confirming S. japonica as a natural and effective tool to increase the nutritional value of juvenile black sea bream.

The effects of magnetic nanoparticles combined with microwave or far infrared thawing on the freshness and safety of red seabream (Pagrus major) fillets

The effects of magnetic nanoparticles combined with microwave thawing (MNPMT) and magnetic nanoparticles combined with far-infrared thawing (MNPFT) on the freshness and amines content of red seabream fillets were investigated. Four thawing methods were used: microwave thawing (MT), far-infrared thawing (FIRT), magnetic nanoparticles combined with microwave thawing (MNPMT) and magnetic nanoparticles combined with far-infrared thawing (MNPFT). The quality of the fresh sample, the sample after thawing and thawed sample after being stored for 6 h were compared by measuring the freshness indexes such as the volatile amino nitrogen content, thiobarbituric acid content, pH value, total number of viable colonies, and the food safety evaluation indexes such as the formaldehyde, dimethylamine, trimethylamine and putrescine contents. The results showed that MNPFT and MNPMT can maintain better freshness than microwave and far-infrared thawing, and the increase in amines content was significantly inhibited.

The effects of CS@Fe3O4 nanoparticles combined with microwave or far infrared thawing on microbial diversity of red seabream (Pagrus major) fillets based on high-throughput sequencing

The present study investigated the effects of CS@Fe3O4 nanoparticles combined with microwave or far infrared thawing on microbial diversity of red seabream (Pagrus major) fillets in terms of thawing loss, pH, TVB-N, classical microbiological enumeration and high-throughput sequencing, and the same parameters were also studied for 24 h after thawing. Four thawing methods were used: microwave thawing (MT), far-infrared thawing (FT), CS@Fe3O4 nanoparticles combined with microwave thawing (CMT) and CS@Fe3O4 nanoparticles combined with far-infrared thawing (CFT). The results showed that CFT and CMT had lower values of pH and TVB-N compared to the FT and MT. Based on conventional microbial count analysis, CFT and CMT samples also maintained lower TVC, pseudomonas and LAB counts. Using high-throughput sequencing analysis, Compared with FT and MT, CFT and CMT samples showed a significant decrease in the proportion of the Pseudomonadaceae flora. However, the proportion of Pseudomonas, Bacillaceae and Thermaceae also increased significantly after 24 h of storage, which indicated that become the predominant microbiota in red seabream (Pagrus major) fillets.

Determination of shelf-life of vacuum-packed sea bream (Sparus aurata) fillets using chitosan-microparticles-coating

ABSTRACT Chitosan-microparticles (CM)-coating (CMC) effect on quality and shelf-life of vacuum-packed sea bream (Sparus aurata) fillets was investigated at 0.2% and0.5% (w/w) doses comparatively to untreated control, during refrigerated storage (24 days). Analysis concerned total mesophilic bacteria counts (TMC), total psychrophilic bacteria counts (TPC), proximate composition, pH, total volatile basic nitrogen (TVB-N), trimethylamine (TMA), thiobarbyturic acid (TBA), and fatty acids (FA). Two-way ANOVA and multiple comparison were applied, factors being storage time and treatment. Bacterial counts exceeded the limit in control but remained below in CMC lots. All of TVB-N, TMA and TBA increased faster and reached higher values in control compared to CMC lots, with dose-dependent effect. CMC preserved quality in terms of proximate composition and FA. The 0.5%-CM dose prolonged the shelf-life up to 12 days, corresponding to a two folds extension. CMC showed antimicrobial and antioxidant properties and should be recommended for preserving the quality of fish fillets.

Modelling the interaction of the sakacin-producing Lactobacillus sakei CTC494 and Listeria monocytogenes in filleted gilthead sea bream (Sparus aurata) under modified atmosphere packaging at isothermal and non-isothermal conditions

The objective of this work was to quantitatively evaluate the effect of Lactobacillus sakei CTC494 (sakacin-producing bioprotective strain) against Listeria monocytogenes in fish juice and to apply and validate three microbial interaction models (Jameson, modified Jameson and Lotka Volterra models) through challenge tests with gilthead sea bream (Sparus aurata) fillets under modified atmosphere packaging stored at isothermal and non-isothermal conditions. L. sakei CTC494 inhibited L. monocytogenes growth when simultaneously present in the matrix (fish juice and fish fillets) at different inoculation ratios pathogen:bioprotector (i.e. 1:1, 1:2 and 1:3). The higher the inoculation ratio, the stronger the inhibition of L. monocytogenes growth, with the ratio 1:3 yielding no growth of the pathogen. The maximum population density (Nmax) was the most affected parameter for L. monocytogenes at all inoculation ratios. According to the microbiological and sensory analysis outcomes, an initial inoculation level of 4 log cfu/g for L. sakei CTC494 would be a suitable bioprotective strategy without compromising the sensory quality of the fish product. The performance of the tested interaction models was evaluated using the Acceptable Simulation Zone approach. The Lotka Volterra model showed slightly better fit than the Jameson-based models with 75–92% out of the observed counts falling into the Acceptable Simulation Zone, indicating a satisfactory model performance. The evaluated interaction models could be used as predictive modelling tool to simulate the simultaneous behaviour of bacteriocin-producing Lactobacillus strains and L. monocytogenes; thus, supporting the design and optimization of bioprotective culture-based strategies against L. monocytogenes in minimally processed fish products.

Mitochondrial activity as an indicator of fish freshness

The current methods used to routinely assess freshness in the fishing industry reflect more a state of spoilage than a state of freshness. Mitochondria, the seat of cellular respiration, undergo profound changes in post mortem tissues. The objective of this study was to demonstrate that mitochondrial activity constitutes a putative early fish freshness marker. The structure of gilthead sea bream (Sparus aurata) muscle tissue was evaluated over time by transmission electron microscopy. Respiration was assessed in mitochondria isolated from sea bream fillets using oxygraphy. Membrane potential (ΔΨm) was determined by fluorescence (Rhodamine 123). Mitochondrial activity of fillets stored at +4 °C was studied for 6 days. Changes in mitochondrial cristae structure appeared from Day 3 highlighting the presence of dense granules. ΔΨm and mitochondrial activity were significantly disrupted in sea bream fillets after 96 h of storage at +4 °C. Mitochondrial activity constituted a reliable and early indicator of fish freshness.

The impact of recrystallisation on the freeze‐thaw cycles of red seabream (Pagrus major) fillets

SummaryRecrystallisation often occurs in the freeze‐thaw cycles and results in poor food quality. This study was undertaken to analyse the effects of recrystallisation on the changes of protein conformation and moisture migration within red seabream fillets after the freeze‐thaw cycles. The UV second‐derivative spectroscopy, intrinsic fluorescence measurement and Raman spectroscopy were employed to evaluate the protein conformational changes. The Low‐field NMR spectra analysis was used to evaluate moisture migration. The results indicated that the freeze‐thaw cycles altered the secondary and tertiary structure of proteins. It was noticed that interactions between water and protein molecules were decreased gradually and eventually induced the thermal instability of the myosin molecules. The immobilised water content declined and the free water content increased. There were significant destructions in fillet muscle microstructure. These observations unambiguously reflect how the recrystallisations affect the protein conformation and moisture migration patterns of red seabream fillets during freeze‐thaw cycles.

Determination of quality parameters of gilthead sea bream (Sparus aurata) fillets coated with electrospun nanofibers

AbstractThe changes in texture, color, and odor parameters of the samples (C: uncoated samples, CN: the group coated with chitosan‐based nanofibers, TLCN: the samples coated with thymol‐loaded chitosan‐based electrospun nanofibers) were tested. The changes in color of the groups were defined by using L* (lightness), a* (red/green), and b* (blue/yellow) parameters for pH values of C, CN, and TLCN. In terms of microbial spoilage, psychrophilic bacteria counts (TPBc) of the samples were revealed during storage period. The results of microbiological, sensory, and psychochemical analysis demonstrated that CN and TLCN were both effective against rapid deterioration, exhibiting up to 100% limitation of deterioration; furthermore, TLCN was more effective than that of CN samples. The study results suggested that coating of gilthead sea bream fillets with CN and TLCN would be a promising approach to delay the rapid deterioration in sensory properties (odor, texture, and color) and the delay bacteria growth. Also, the rapid changes in the physicochemical quality parameters (pH, L*, a*, and b*) of fish fillets were controlled by using electrospun nanofiber coating technique.Practical applicationsCoating of the fish fillets with chitosan‐based nanofibers delayed the deterioration. Thymol‐loaded chitosan‐based nanofibers were more effective to delay the deterioration. Applied tests revealed almost 100% difference between groups.

Effect of coating with thymol-loaded chitosan-based electrospun nanofibers on fatty acid composition of gilthead sea bream fillets (Sparus aurata)

Effect of coating with thymol-loaded chitosan-based electrospun nanofibers on fatty acid composition of gilthead sea bream fillets (Sparus aurata)

Effect of magnetic nanoparticles plus microwave or far-infrared thawing on protein conformation changes and moisture migration of red seabream (Pagrus Major) fillets

In order to evaluate the effects of magnetic nanoparticles plus microwave (MNPMT) or far-infrared (MNPFT) thawing on protein conformation changes and moisture migration of red seabream (Pagrus major) fillets, cold storage thawing, microwave thawing, MNPMT, far-infrared thawing and MNPFT were subjected to red seabream fillets. DSC and dynamic rheology were conducted to analyze physicochemical changes. Raman spectra before and after isotope H/D exchange, intrinsic fluorescence and UV second derivative spectra were carried out to explore myofibrillar protein structural changes. Low-field NMR was used to test water migration. SEM was performed to observe fiber microstructure. Results indicated that MNPMT and MNPFT both had a desirable thermal stability and gelation property. Besides, both showed stable protein secondary and tertiary structure. Immobilized water in them also had no significant changes compared with fresh sample. This research provided some novel thawing technologies for application in food industry.