Sea Bream Fillets Research Articles

Ultrasound or microwave vacuum thawing of red seabream (Pagrus major) fillets

Ultrasound assisted vacuum thawing (UVT) or microwave vacuum thawing (MVT) with red seabream fillets were compared to fresh, chill storage thawing, vacuum thawing, microwave thawing and ultrasound thawing. The thermal stability and gelation properties were studied with DSC and dynamic rheology, respectively. Raman spectra before and after H/D isotope exchange and intrinsic fluorescence were used to measure protein secondary and tertiary structure. Low-field NMR was done to measure water migration. The two thawing techniques both retained actin thermal stability and generally retained more stable tertiary structures than the other thawing methods. MVT showed a desirable viscoelasticity of muscle proteins and UVT had a relatively stable secondary structure. There were no significant changes in free water. Thus, UVT and MVT could be used to improve the physicochemical properties of proteins during thawing of fillets.

Treatment With High-Hydrostatic Pressure, Activated Film Packaging With Thymol Plus Enterocin AS-48, and Its Combination Modify the Bacterial Communities of Refrigerated Sea Bream (Sparus aurata) Fillets.

The aim of this study was to determine the impact of activated plastic films with thymol and enterocin AS-48 and high-hydrostatic pressure (HP) treatment on the bacterial load and bacterial diversity of vacuum-packaged sea bream fillets under refrigerated storage for 10 days. The activated film and the HP treatment reduced aerobic mesophiles viable counts by 1.46 and 2.36 log cycles, respectively, while the combined treatment achieved a reduction of 4.13 log cycles. HP and combined treatments resulted in longer delays in bacterial growth. Proteobacteria were the dominant phyla in sea bream fillets. The relative abundance of Firmicutes increased by the end of storage both in controls and in samples treated by HP singly or in combination with the activated films. The predominant operational taxonomic units (OTUs) found at time 0 in control samples (Listeria, Acinetobacter, Pseudomonas, Enterobacteriaceae, Chryseobacterium) rapidly changed during storage (with an increase of Vibrio, Photobacterium, and Shewanella together with Cloacibacterium and Lactobacillales by the end of storage). The activated film and the HP treatment induced drastic changes in bacterial diversity right after treatments (with Comamonadaceae, Methylobacterium, Acidovorax, and Sphingomonas as main OTUs) and also induced further modifications during storage. Bacterial diversity in activated film samples was quite homogeneous during storage (with Vibrio, Photobacterium, and Shewanella as main OTUs) and approached control samples. HP treatments (singly or in combination with activated films) determined a high relative abundance of Acinetobacter (followed by Pseudomonas and Shewanella) during early storage as well as a higher relative abundance of lactic acid bacteria by the end of storage. The results indicate that the complex dynamics of bacterial populations in the refrigerated sea bream fillets are markedly influenced by treatment and antimicrobials applied.

Inactivation of Listeria in Foods Packed in Films Activated with Enterocin AS-48 plus Thymol Singly or in Combination with High-Hydrostatic Pressure Treatment

The aim of the present study was to determine the efficacy of films activated with enterocin AS-48 plus thymol singly, or in combination with high-hydrostatic pressure (HHP) on the inactivation of Listeria innocua in sea bream fillets and in fruit puree stored under refrigeration for 10 days. L. innocua proliferated in control fish fillets during storage. The activated film reduced viable Listeria counts in fillets by 1.76 log cycles and prevented growth of survivors until mid-storage. Application of HHP treatment to fillets packed in films without antimicrobials reduced Listeria counts by 1.83 log cycles, but did not prevent the growth of survivors during storage. The combined treatment reduced viable counts by 1.88 log cycles and delayed growth of survivors during the whole storage period. L. innocua survived in puree during storage. The activated film reduced Listeria counts by 1.80 and 2.0 log cycles at days 0 and 3. After that point, Listeria were below the detection limit. No viable Listeria were detected in the purees after application of HHP treatment singly, or in combination with the activated film. Results from the study indicate that the efficacy of activated films against Listeria is markedly influenced by the food type.

Coating with chitosan film of sea bream (Sparus aurata) fillets: determining shelf life in refrigerator conditions

Abstract In the investigate, we objectived to assess the effect of coating with chitosan film on the shelf life. To this end, skinless sea bream fillets were separated as control group (C), vacuum packed (VP) and coated with chitosan film and vacuum packed (CF+VP). Samples of each group were periodically analyzed for microbiological [Total mesophilic aerobic count (TMAc) and Total psychrophilic aerobic count (TPAc)] and physicochemical [pH, Total volatile basic nitrogen (TVB-N), Thiobarbituric acid (TBA) and Trimethylamine nitrogen (TMA-N)] in storage time. It was determined that CF+VP had the highest shelf life among the sample groups. The findings of the study showed that covering sea bream fillets with chitosan film and vacuum packaging significantly prolongs the consumption of the sea bream fillets.

Amino acid composition of gilthead sea bream fillets (Sparus aurata) coated with thymol-loaded chitosan nanofibers during cold storage

Amino acid composition of gilthead sea bream fillets (Sparus aurata) coated with thymol-loaded chitosan nanofibers during cold storage

A Novel Approach to Limit Chemical Deterioration of Gilthead Sea Bream(Sparus aurata)Fillets: Coating with Electrospun Nanofibers as Characterized by Molecular, Thermal, and Microstructural Properties.

Coating of sea bream fillets with thymol loaded chitosan based electrospun nanofibers (TLCN) and chitosan based nanafibers (CN) has been presented a novel approach to delay chemical deterioration. We assessed CN and TLCN with respect of scanting of total volatile basic nitrogen (TVBN), trimethylamine (TMA), thiobarbituric acid (TBA) deterioration during cold storage condition. Electrospinning process was applied to obtain TLCN and CN. Both of nanofibers obtained from biopolymer and bioactive material were cylindrical, smooth, beadless. Thermal, molecular, zeta potential (ZP), and surface properties of the groups were investigated, revealing that CN indicated molecular interactions with thymol in nanofibers, reduce in physical properties of these structures, thermal decomposition (an alteration in mass of CN and TLCN at temperatures below 190 °C, corresponding to 20.53% and 19.97%, respectively) and also dispersion stabilities (ζ potential) of CN and TLCN were determined 33.68 ± 3.35 and 21.85 ± 1.96 mV, respectively. TVBN and TMA stability analyses demonstrated that CN and TLCN were both effective in delaying chemical deterioration of fish fillets, furthermore TLCN was more effective against chemical deterioration. TBA analyses results of fish fillets indicated that CN and TLCN delayed rancidity in fish meat as compared to control group samples. The presented study results suggested that coating of the sea bream fillets with CN and TLCN would be a promising approach to delay the chemical deterioration of fish fillets.

Fatty Acid Composition of Gilthead Sea Bream (Sparus aurata) Fillets as Affected by Current Changes in Aquafeed Formulation

Fatty Acid Composition of Gilthead Sea Bream (Sparus aurata) Fillets as Affected by Current Changes in Aquafeed Formulation

Volatile organic compounds of microbial and non-microbial origin produced on model fish substrate un-inoculated and inoculated with gilt-head sea bream spoilage bacteria

Volatile organic compounds (VOCs) origination during fish spoilage is attributed to either decomposition of fish constituents or metabolic activity of spoilage bacteria. To identify microbiological spoilage markers it is essential to know which VOCs are microbial metabolites. VOCs produced in sterile fish juice agar (FJA) model substrate made from gilt-head sea bream (Sparus aurata) flesh juice, inoculated or not with spoilage bacteria isolated from sea bream fillets were detected using SPME/GC-MS technique. Three groups of spoilage bacteria (Pseudomonas, Shewanella and Carnobacterium/Lactobacillus strains) were used to inoculate Petridishes with FJA and stored at 0 and 15 °C under air and commercial Modified Atmosphere Package (MAP CO2: 60%, O2: 10%, N2: 30%). Bacterial growth was also monitored. VOCs that were detected in sterile substrate and their amounts were not higher in inoculated FJA were presumably of non-microbial origin. VOCs that were detected only in inoculated FJA were metabolic products of spoilage bacteria. Some of VOCs were associated with metabolic activity of a particular microbial group, e.g. ethyl esters were associated with Pseudomonas, while 2-, 3-methylbutanal and 3-hydroxy-2-butanone with LAB. Few microbial metabolites increased during storage showing their potential as spoilage markers of gilt-head sea bream and the possible use for rapid freshness assessment.

Effect of storage temperature and osmotic pre-treatment with alternative solutes on the shelf-life of gilthead seabream (Sparus aurata) fillets

The objective of the study was the kinetic modelling of the shelf-life of osmotically pre-treated fish during refrigerated and super-chilled storage. Fresh gilthead seabream (Sparus aurata) fillets were treated for 0–360 min at 15 °C in osmotic solutions 50:5 high dextrose equivalent maltodextrin:NaCl/100 g (HDM), 40:10:5 HDM:trehalose:NaCl/100 g (HDM + treh) and 40:10:5 HDM:glucosamine:NaCl/100 g (HDM + gluc). Water loss, solid gain, salt content and water activity were monitored throughout treatment. Slices untreated and osmotically pre-treated for 45 min were aerobically packed and stored isothermally at 15, 10, 5, 2.5, 0, −1 and −3 °C. Quality assessment was based on microbial growth (total viable count, Pseudomonas spp., Brochothrix thermosphacta, Enterobacteriaceae spp., H2S-producing bacteria, lactic acid bacteria, yeasts and moulds), total volatile nitrogen (TVB-N), lipid oxidation (TBARs) and sensory scoring. Quality indices were kinetically modelled and temperature dependence of quality loss rates was modelled by Ratkowsky equation.Osmotic pre-treatment led to significant shelf-life extension of fillets, in terms of microbial growth, chemical changes and organoleptic deterioration. The pre-treatment with the alternative solutes led to depression of the freezing point (−1.8, −2.6, −3.2 and −3.5 °C for the untreated samples and the osmotically pre-treated with HDM, HDM + treh and HDM + gluc, respectively). TVB-N values were higher in untreated samples, followed by osmotically treated fillets, mainly at higher storage temperatures (i.e. 10 and 15 °C). Based on the mathematical models for sensory evaluation scoring, the shelf-life was 12, 19, 22 and 22 days at 0 °C for untreated and osmotically pre-treated with HDM, HDM + treh and HDM + gluc fish slices, respectively, while the respective values at −3 °C were 21, 35, 38 and 38 days. The alternative solutes had no significant effect on the quality and shelf-life of pre-treated fish fillet during storage at refrigerated conditions.

Activity of R(+) limonene on the maximum growth rate of fish spoilage organisms and related effects on shelf-life prolongation of fresh gilthead sea bream fillets

R(+)limonene (LMN) is the major aromatic compound in essential oils obtained from oranges, grapefruits, and lemons. The improvement of preservation techniques to reduce the growth and activity of spoilage microorganisms in foods is crucial to increase their shelf life and to reduce the losses due to spoilage. The aim of this work is to evaluate the effect of LMN on the shelf life of fish fillets. Its effectiveness was preliminarily investigated in vitro against 60 strains of Specific Spoilage Organisms (SSOs) and then on gilt-head sea bream fillets stored at 2±0.5°C for 15days under vacuum. LMN showed a good inhibitory effect against tested SSOs strains. On gilt-head sea bream fillets, LMN inhibited the growth SSOs effectively, and its use resulted in a shelf-life extension of ca. 6–9days of treated fillets, compared to the control samples. The LMN addition in Sparus aurata fillets giving a distinctive smell and like-lemon taste to fish fillets that resulted pleasant to panellists. Its use contributed to a considerable reduction of fish spoilage given that the fillets treated with LMN were still sensory acceptable after 15days of storage. LMN may be used as an effective antimicrobial system to reduce the microbial growth and to improve the shelf life of fresh gilt-head sea bream fillets.

Antimicrobial and antioxidant activity of Satureja thymbra in gilthead seabream fillets edible coating

The effectiveness of Satureja thymbra (L.) extracts as potential antimicrobial or antioxidant agents in fish coating was studied. Dried leaves of the plant were subjected to steam distillation to recover the essential oil (EO). The solid residue was extracted successively with ethyl acetate and ethanol to recover the phenolic compounds. γ-Terpinene and carvacrol were the main components of EO, according to GC–MS analysis. LC–DAD–MS analysis of the extracts showed the presence of four main flavonoids and their derivatives in ethyl acetate, while rosmarinic and salvianolic acid A predominated in ethanol extract.The EO, ethyl acetate extract (EAcs), ethanol extract (Es), and their combinations were used in edible films to prolong the shelf life of fresh gilthead seabream (Sparus aurata) fillets. CMC solutions enriched with the extracts were prepared, the sliced fish fillets were soaked for 5min in the solutions, packed aerobically, and stored at 0°C. Microbial growth and oxidative deterioration was estimated. EO used alone showed a moderate antimicrobial and antioxidant protection. The EAcs and EAcs-EO combination showed the best antimicrobial effect, resulting in 25 and 35% shelf life extension, while the Es and Es-EO combination the best antioxidant activity, reducing the peroxide values by approximately threefold and eliminating the formation of secondary oxidation products.

Assessment of freshness and freeze-thawing of sea bream fillets (Sparus aurata) by a cytosolic enzyme: Lactate dehydrogenase

The evaluation of freshness and freeze-thawing of fish fillets was carried out by assessment of autolysis of cells using a cytosolic enzyme lactate dehydrogenase. Autolysis plays an important role in spoilage of fish and postmortem changes in fish tissue are due to the breakdown of the cellular structures and release of cytoplasmic contents. The outflow of a cytosolic enzyme, lactate dehydrogenase, was studied in sea bream fillets and the Sparus aurata fibroblasts (SAF-1) cell-line during an 8day storage period at +4°C. A significant increase of lactate dehydrogenase release was observed, especially after 5days of storage. The ratio between the free and the total lactate dehydrogenase activity is a promising predictive marker to measure the quality of fresh fish fillets. The effect of freeze-thawing on cytosolic lactate dehydrogenase and lysosomal α-d-glucosidase activities was also tested. Despite the protecting effect of the tissue compared to the cell-line, a loss of lactate dehydrogenase activity, but not of α-d-glucosidase, was observed. In conclusion, lactate dehydrogenase may be used as a marker to both assess freshness of fish and distinguish between fresh and frozen-thawed fish fillets.

Effects of allyl isothiocyanate on the shelf-life of gilthead sea bream (Sparus aurata) fillets

The effect of allyl isothiocyanate (AITC), a natural compound found in plants belonging to the family Cruciferae, on the shelf-life of fish fillets was evaluated. Preliminarily, the effectiveness of AITC was investigated in vitro against some strains of Specific Spoilage Organisms (SSOs). The inhibitory effect of AITC vapour was screened evaluating the bacterial growth in a jar. A strong inhibitory effect against the tested SSOs was observed. Successively, the shelf-life of gilthead sea bream fillets treated with AITC vapour and stored at 2°C was evaluated and compared with untreated samples. AITC inhibited the growth of SSOs effectively, and its use resulted in a shelf-life extension by ca. 8 days in treated fillets, compared to the control samples. The AITC addition in fillets yielded a distinct but pleasant flavour and contributed to a considerable reduction of fish spoilage.

The atherosclerotic risk profile is affected differently by fish flesh with a similar EPA and DHA content but different n-6/n-3 ratio.

The aim of this study was to evaluate the effect of consuming gilthead sea bream fillets, with different n-6/ n-3 ratios, on atherosclerotic biomarkers. Twenty healthy subjects were included in a randomised single-blinded cross-over trial. Participants were randomized into 2 groups, both of which received approximately 630 g per week of gilthead sea bream fed with either 100% fishmeal (FM) or partial replacement with plant proteins (PP) over two consecutive 10 week periods, respectively. Group A consumed firstly the FM fillets followed by the PP fillets, whereas the reverse order was adopted for group B. Group A reported a significant decrease of 29.3% (Δ = -26 mg/dL) in total cholesterol after the first phase of the intervention, before returning to baseline levels after the dietary intervention with fish fed with PP. Similarly, in group A, both LDL-cholesterol and triglycerides decreased significantly by 21.6% (Δ = -19 mg/dL) and 11.7% (Δ = -10.7 mg/dL), respectively, before increasing again after the intervention. Improvements in the inflammatory cytokines, interleukin-6 and -8 were also noted. Moreover, whole blood viscosity appeared significantly improved in group A, as seen by a significant increase of 7.59% (Δ = +4.59 mPA) for erythrocyte filtration rate. In conclusion, similar EPA+DHA content with different n- 6/n-3 ratio fish flesh intake was shown to have varied affects on lipid, inflammatory and haemorheological parameters in a group of healthy subjects.

Optimizing Salting and Immersion Time in Liquid Smoke of Farmed Gilthead Sea Bream (Sparus aurata) Fillets Using Response Surface Methodology

Optimizing Salting and Immersion Time in Liquid Smoke of Farmed Gilthead Sea Bream (Sparus aurata) Fillets Using Response Surface Methodology

Preliminary Investigation on the Use of Allyi Isothiocyanate to Increase the Shelf-Life of Gilthead Sea Bream (Sparus Aurata) Fillets.

The aim of this work is to evaluate the activity of allyl isothiocyanate (AITC) against fish spoilage bacteria (specific spoilage organisms; SSOs) as well as its possible use in gilthead sea bream (Sparus aurata) fillets to extend their shelf-life. In this regard, in vitro tests are carried out in order to evaluate the inhibitory activity of AITC and its vapours on several strains of SSOs. The AITC effect on the shelf-life of sea bream fillets was made by putting them in plastic trays hermetically closed with the addition AITC. Microbiological and sensorial evaluations were made on fish fillets during storage. Treated fillets maintained microbial populations at a significantly lower level compared with the control samples during storage, showing better sensorial characteristics. Therefore, the use of AITC’s vapours seems to be a new and interesting alternative way to increase fish product shelf-life.

Identification of isobaric lyso-phosphatidylcholines in lipid extracts of gilthead sea bream (Sparus aurata) fillets by hydrophilic interaction liquid chromatography coupled to high-resolution Fourier-transform mass spectrometry.

The numerous and varied biological roles of phosphatidylcholines (PC) and lysophosphatidylcholines (LPC) have fueled a great demand for technologies that enable rapid, in-depth structural examination of these lipids in foodstuffs. Here, we describe the capabilities of a newly configured combination of high-efficiency liquid chromatography and high-resolution/accuracy Fourier-transform mass spectrometry with electrospray ionization (LC-ESI-FTMS), designed for lipidomics applications that require the identification of PC in their lyso forms. The devised strategy, involving a separation by hydrophilic interaction liquid chromatography (HILIC) on spherical, fused-core ultrapure silica particles (2.7μm) of a narrow-bore column (2.1mm i.d.), enabled the identification of as many as 71 LPC species in the lipid extracts of gilthead sea bream (Sparus aurata) fillets. In this way, LPC as proton (43) and sodium (28) adducts, i.e., [M + H](+) and [M + Na](+) ions (with M representing the zwitterionic form), were identified. In several cases, the extremely high (sub-ppm) mass accuracy and the high chromatographic efficiency available with the adopted instrumentation enabled the distinction of isobaric and closely eluting LPC species. Informative tandem mass spectra, based on high-energy collision induced dissociation (HCD), were also obtained, thus distinguishing regioisomeric LPC species (i.e., LPC differing only for the location of the residual side chain on the glycerol backbone) and between proton and sodium adducts. Graphical Abstract Extracted Ion Current chromatogram (XIC) obtained for the m/z value 568.339, showing the presence of two regioisomeric Lysophosphatidylcholines. The corresponding high collisional energy tandem MS spectra, obtained using a HCD cell, are shown as insets.

Effect of alginate coating enriched with 6-gingerol on the shelf life and quality changes of refrigerated red sea bream (Pagrosomus major) fillets

The study aimed to determine the shelf life and quality changes of red sea bream which is coated by using sodium alginate (SA) enriched with 6-gingerol (GR) during 20 days of refrigerated storage (4 ± 1 °C).

3-Chlorotyrosine formation in gilthead seabream (Sparus aurata) and European plaice (Pleuronectes platessa) fillets treated with sodium hypochlorite

The chlorination of tyrosine in fish fillets as a result of hypochlorite dipping was investigated and the formation of 3-chlorotyrosine was proved to be reproducible (average RSD<6.0%). In European plaice, 0.85% (inner portion) and 1.88% (surface) of tyrosine were converted to 3-chlorotyrosine after 60min dipping in 2000mg/L NaOCl. As the dose of hypochlorite acid increased to 7816mg/L, those percentages were 1.07% and 2.81%, respectively. Experiments on gilthead seabream showed the clear impact of dipping time and NaOCl concentration on the formation of 3-chlorotyrosine at the fillet surface and the levels of 3-chlorotyrosine reached a plateau at 1000mg NaOCl/L. At the same dipping time, the 3-chlorotyrosine contents increased noticeably from about 1.40 to 4.90ppm in gilthead seabream fillets treated with 125–1000mg/L NaOCl. 3-chlorotyrosine formation was evaluated in four fish species (whiting, European plaice, gilthead seabream and Atlantic salmon) and proved to be species dependent, but no direct with the fat content could be found. During the chilled storage (4°C), the 3-chlorotyrosine was constant. The use of 31mg OClˉ/L could be detected for seabream.

Dietary macroalgae is a natural and effective tool to fortify gilthead seabream fillets with iodine: Effects on growth, sensory quality and nutritional value

Marine fish are a rich source of iodine in the human diet. Exogenous feeding under captivity opens the possibility of tailoring fish composition with health valuable nutrients, such as iodine, and establishing it as a functional food. A study was undertaken to test the efficacy of various dietary iodine supplemental forms on the growth performance of gilthead seabream and assess the effects on sensory attributes and nutritional value of fillets. Duplicate groups of 35 seabream (IBW: 252 g) were fed over 118 days: a) control diet (CTRL) with 3 mg I kg− 1, supplied as potassium iodide; b) this same control diet supplemented with potassium iodide (diet KI: 26 mg I·kg− 1) or with ethylenediamine dihydroiodide (diet EDDI; 22 mg I·kg− 1); c) a fourth diet with 10% of Laminaria digitata, an iodine-rich macroalgae (diet LAM). At the end of the trial, fish doubled their initial weight, but irrespective of the iodine form used, the elevation of dietary iodine level had no effect (P > 0.05) on feed intake, growth rate, feed conversion, nutrient utilization or whole-body composition. Dietary iodine supplementation led to a significant increase (P < 0.05) of the iodine content in seabream fillets. In comparison to the CTRL treatment (0.13 mg·kg− 1), seabream fed KI and EDDI supplemented diets showed a significant enhancement (P < 0.05) of their fillet iodine content (0.17 mg·kg− 1). Feeding seabream with the iodine-rich brown algae L. digitata resulted in a significant (P < 0.05) 6.5-fold increase (0.84 mg·kg− 1 fillet) of fillet iodine content over the levels found in the CTRL treatment. Overall sensory difference between CTRL and fish fed supplemented diets was significant (P < 0.05) only for fish fed the EDDI diet. Steam-cooking elicited 13–20% losses of the iodine content of seabream fillets. Iodine supplementation had no effect (P > 0.05) on the fatty acid profile of seabream muscle. Dietary iodine-rich macroalgae was an effective and natural strategy to fortify muscle with iodine, showing that a 160 g portion of steam-cooked seabream fillets could cover approximately 80% of the Daily Recommended Intake for iodine and 370% of the Daily Adequate Intake of EPA + DHA for enhanced cardiovascular health in adults.