Effects of four cooking methods on the heavy metal concentrations of sea bass fillets (Dicentrarchus labrax Linne, 1785)

Heavy metals (Pb, Cd, Cr, Co, As, Ni) were analysed in cooked sea bass (Dicentrachus labrax). Different cooking treatments were used (baking, grilling, microwaving and frying). The results obtained were statistically compared with those of raw fish. The Co concentrations were below limits of detection in all samples (<0.05). Furthermore, Cr in fried samples and Ni in raw fish were not detected. Cd was only detected in microwaved samples. The Pb concentrations of microwaved and baked fish were significantly decreased. The As concentrations of fried and microwaved samples were significantly increased. The Cd and As concentrations of the fillets subjected to microwave cooking were 0.741 and 1.41 mg/kg, respectively. However, the As concentration was also significantly increased in fried samples. This value was 2.66 mg/kg. Microwaving and frying are not suitable for sea bass.     

Assessing the quality of organic and conventionally-farmed European sea bass (Dicentrarchus labrax)

The biometric and nutritional traits of European sea bass from organic or semi-intensive conventional production systems at two commercial sizes (small and medium) were compared. The analysis included a total of 80 specimens. The biometric traits and the texture were not affected by the rearing system, whereas they changed significantly with fish size. The fillet fatty acid profile varied significantly, both with rearing system and sea bass size, depending on the fatty acid profile of the diets. The ratio of n − 3 to n − 6 polyunsaturated fatty acids was higher (p < 0.001) in organic than in conventional fish (1.60 vs. 0.54) and in small than in medium-sized sea bass (1.15 vs. 0.98). Near infrared reflectance spectroscopy (NIRS) successfully classified fillets according to sea bass size in both fresh-minced and freeze-dried samples (90% correct classification), whereas it only classified organic vs. conventional sea bass fairly well (65-75% correct classification) for freeze-dried fillets.     

Microbiological,chemical and sensory changes of whole and filleted Mediterranean aquacultured sea bass (Dicentrarchus labrax) stored in ice

The effect of filleting on the microbiological, chemical and sensory properties of aquacultured sea bass (Dicentrarchus labrax) stored in ice was studied. Pseudomonads, H₂S‐producing bacteria (including Shewanella putrefaciens) and Brochothrix thermosphacta were the dominant bacteria at the end of the 16 day storage period in ice for both whole ungutted and filleted sea bass. Enterobacteriaceae were also found in the spoilage microflora of whole ungutted and filleted sea bass, but their counts were always lower than those of pseudomonads, H₂S‐producing bacteria (including S putrefaciens) and B thermosphacta. Total viable counts for whole ungutted sea bass were always lower than those for filleted sea bass samples. Of the chemical indicators of spoilage, TMA (trimethylamine) values of whole ungutted sea bass increased very slowly, whereas significantly higher values were obtained for filleted samples, with respective values of 0.253 and 1.515 mg N per 100 g muscle being reached at the end of their shelf‐life (days 13 and 9 respectively). TVB‐N (total volatile basic nitrogen) values showed a slight increase for whole ungutted sea bass during storage, reaching a value of 26.77 mg N per 100 g muscle (day 13), whereas for filleted fish a corresponding value of 26.88 mg N per 100 g muscle was recorded (day 9). TBA (thiobarbituric acid) values increased slowly for whole ungutted and filleted sea bass samples throughout the entire storage period, reaching final values of 4.48 (day 13) and 13.84 (day 9) mg malonaldehyde kg^?1 respectively. Sensory assessment of raw fish using the EC freshness scale gave a grade E for up to 5 days for whole ungutted sea bass, a grade A for a further 4 days and a grade B for an additional 4 days, after which sea bass was graded as C (unfit). Overall acceptability scores for odour, taste and texture of cooked whole ungutted and filleted sea bass decreased with increasing time of storage. The results of this study indicate that the shelf‐life of sea bass stored in ice, as determined by overall acceptability sensory scores and microbiological data, is 8–9 days for filleted and 12–13 days for whole ungutted fish. Copyright © 2003 Society of Chemical Industry     

Detection and quantification of 47 antibiotic residues in farmed European sea bass (Dicentrarchus labrax) using a multi-class and multi-residue UHPLC-MS/MS method

In the present study, a multi-class multi-residue method for the simultaneous detection and determination of antibiotics in European sea bass (Dicentrarchus labrax) was developed and validated. The method based on UHPLC-MS/MS proved to be a rapid, highly selective and sensitive tool, requiring minimum sample preparation, for screening and detection of 47 compounds from eight different classes. The validation was performed according to EU regulation 2002/657/EC, proving the method’s suitability for application in routine analysis. The method was applied to the analysis of 30 samples of farmed European sea bass purchased in different supermarkets in Portugal. Antibacterial residues were detected in 6 of the 30 analysed samples, namely enrofloxacin and oxytetracycline, in concentrations ranging from 0.1 to 12 µg kg^?1.     

Gutted and Un-Gutted Sea Bass (Dicentrarchus Labrax) Stored in Ice: Influence on Fish Quality and Shelf-Life

The sensory characteristics, chemical freshness indicator contents, and microbial counts (total aerobe, psychrotrophic bacteria, H₂S-producing bacteria, and Pseudomonas spp.) of whole un-gutted and gutted sea bass stored in ice were compared. Results of this study indicated that the acceptability quality of whole and gutted sea bass as determined by sensorial data is 11 days, respectively. No significant differences (p > 0.05) were found in the level of sensory score between whole and gutted sea bass samples. Total volatile basic nitrogen (TVB-N) values showed no significant increase for whole and gutted sea bass during storage. Trimethylamin (TMA-N) values of whole and gutted sea bass increased very slowly, reaching final values of 3.94 and, 3.38 mg/100g, respectively (day 13). Development of initial decomposition (after 7 days) occurred when bacterial counts were > 4 log CFU/g. Microbial counts showed a significant increase for whole and gutted sea bass during storage. Significant differences (p < 0.05) were found in the microbial counts between whole and gutted sea bass samples. This difference, may be attributed either to gutting procedures, which most probably were the cause of cross-contamination of fish or to the significantly higher fish flesh surface area exposed to environmental microbial contamination in the case of gutted fish.     

Quality assessment of gutted wild sea bass (Dicentrarchus Labrax) stored in ice, cling film and aluminium foil

The effects of aluminium foil and cling film on microbiological, chemical and sensory changes in wild sea bass (Dicentrarchus labrax) stored at chill temperature (4 °C) were studied. A quality assessment of wild sea bass stored in ice, in boxes without ice, wrapped in aluminium foil (WAF) and wrapped in cling film (WCF) at 4 °C was performed by monitoring sensory quality, nucleotide breakdown products, total volatile base nitrogen (TVB-N), and total viable counts (TVCs). The observed organoleptic shelf-life of sea bass was found to be 16 days in ice, 4 days in boxes without ice, 8 days in aluminium foil and 8 days in cling film. Demerit points did not differ significantly (P>0.05) between WCF fish and WAF fish. The nucleotide degradation pattern was found to be similar for all storage conditions except for inosine and hypoxanthine contents, which decreased after 12 days of storage for WAF and WCF. The content of TVB-N for all storage conditions showed similar tendencies until 12 days storage but reached the highest level (41.6 mg TVB-N 100 g^–1 flesh) for fish stored in WAF and WCF. No significant differences (P>0.05) were found in TVB-N concentrations within the treatments during the early stages of the storage period. Bacteria grew most quickly in the sea bass kept in boxes without ice, followed by those kept WAF, WCF and in ice. Significant differences (P<0.05) in TVC were observed amongst the treatments, especially between fish stored in boxes without ice and fish stored in ice     

Predictive models for bacterial growth in sea bass (Dicentrarchus labrax) stored in ice

The purpose of this paper was to estimate microbial growth through predictive modelling as a key element in determining the quantitative microbiological contamination of sea bass stored in ice and cultivated in different seasons of the year. In the present study, two different statistical models were used to analyse changes in microbial growth in whole, ungutted sea bass (Dicentrarchus labrax) stored in ice. The total counts of aerobic mesophilic and psychrotrophic bacteria, Pseudomonas sp., Aeromonas sp., Shewanella putrefaciens, Enterobacteriaceae, sulphide‐reducing Clostridium and Photobacterium phosphoreum were determined in muscle, skin and gills over an 18‐day period using traditional methods and evaluating the seasonal effect. The results showed that specific spoilage bacteria (SSB) were dominant in all tissues analysed, but were mainly found in the gills. Predictive modelling showed a seasonal effect among the fish analysed. The application of these models can contribute to the improvement of food safety control by improving knowledge of the microorganisms responsible for the spoilage and deterioration of sea bass.     

Level of chlorinated hydrocarbons in a teleost fish and a bivalve from the Egyptian Mediterranean Coast and Nile Estuary

 The residues of 22 organochlorine pollutants in fish Mugil cephalus and a bivalve Donax sp. collected from three different locations, i.e. Abu-Quir bay, Demiatta and Gamasa, were analysed by capillary GLC. The pollutants studied were 1,1,1,-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT) isomers, cyclodiene compounds, dodecachlorooctahydro-1.3.4-metheno-2H-cyclobuto[cd]pentalene (Mirex), methoxychlor, toxaphene and hexachlorobenzene (HCB), Aroclors 1248 and 1254 as well as ten individual polychlorinated biphenyl (PCB) congeners. Extractable organic matter (EOM) levels ranged from 48.0 to 133.0 mg/g, and from 33.0 to 73.0 mg/g in bivalves and fish, respectively. 2,2-bis(p-Chlorophenyl)-1,1-dichlorethylene (p,p′-DDE) dominated other 2,2-bis(p-chlorophenyl)-1,1,1-trichloroethane (DDT) analogues in fish (2.0–4.0 ng/g). 1-chloro-2,2-bis(p-chlorophenyl)ethylene (DDMU) dominated in the bivalve, its concentration ranging from 9.0 to 15.0 ng/g. The concentration of heptachlor was negligible, while endrin and dieldrin were the dominant cyclodienes, occurring in high levels in fish (0.6 and 1.3 ng/g) and bivalves (1.5 and 2.4 ng/g), at Gamasa and Demiatta, respectively. The Aroclor 1248 level was two- to threefold that of Aroclor 1254. As far as the individual PCBs are concerned, less chlorinated biphenyl congeners (from mono- to penta-chloro-biphenyls) were less concentrated except for PCB 200 and PCB 206. Toxaphene was detected at all three locations, at a maximum level of 9.7 ng/g in bivalves from Demiatta. Received: 21 October 1996 / Revised version: 27 March 1997     

Effect of gutting on microbiological,chemical, and sensory properties of aquacultured sea bass (Dicentrarchus labrax) stored in ice

The effect of gutting on microbiological, chemical, and sensory properties of aqua-cultured sea bass (Dicentrarchus labrax) stored in ice was studied. Pseudomonads and H₂S-producing bacteria (including Shewanella putrefaciens) were the dominant bacteria at the end of the 16-day storage period in ice for both whole ungutted and gutted sea bass. Brochothrix thermosphacta and Enterobacteriaceae were also found in the spoilage microflora of ungutted and gutted sea bass but their counts were always less than those of Pseudomonads and H₂S-producing bacteria. Bacterial counts of whole ungutted sea bass were always higher than those obtained for gutted sea bass samples. Mesophilic counts for gutted and ungutted fish exceeded 7 log cfu g⁻¹ after 9 and 15 days of ice storage, respectively. Of the chemical indicators of spoilage, TMA values of ungutted sea bass increased very slowly whereas for gutted samples higher values were obtained reaching a final value of 0.73 and 4.39 mg N 100 g⁻¹, respectively (day 16). TVB-N values showed no significant increase for whole ungutted sea bass during storage reaching a value of 27.7 mg N 100 g⁻¹ (day 16) whereas for gutted fish 36.9 mg N 100 g⁻¹ was recorded. TBA values remained low for ungutted sea bass samples until day 16 of storage, whereas for gutted fish were variable. Of the chemical indices used, none proved useful means of monitoring early ungutted and gutted sea bass freshness in ice. Sensory assessment using the EC freshness scale gave a grade E for up to 5 days for the ungutted sea bass, a grade A for a further 2 days and a grade B for an additional 4 days, after which sea bass was graded as C (unfit). Gutted sea bass was given a grade E for up to 3 days, a grade A for the 4–7th days, and a grade B for the 8–10th days of storage, whereas on day 11 it was graded as unfit. Acceptability scores for odor, taste and texture of cooked ungutted and gutted sea bass decreased with time of storage. Results of this study indicate that the shelf-life of whole ungutted and gutted sea bass stored in ice as determined by the overall acceptability sensory scores and microbiological data is 13 and 8 days, respectively.     

Investigation of selected persistent organic pollutants in farmed Atlantic salmon (Salmo salar), salmon aquaculture feed,and fish oil components of the feed

There is extensive literature documenting the bioaccumulation of persistent organic pollutants in the marine environment, but relatively little data are available on contamination pathways in aquaculture systems such as that for farmed salmon. In recent years,the salmon industry has grown significantly in Europe. This study reports on the determination of a wide range of polychlorinated biphenyls (PCBs), organochlorine pesticides, and polybrominated diphenyl ethers (PBDEs) in farmed and wild European Atlantic salmon fish, aquaculture feeds, and fish oils used to supplement the feeds. The study confirms previous reports of relatively high concentrations of PCBs and indicates moderate concentrations of organochlorine pesticides and PBDEs in farmed Scottish and European salmon. Concentrations of the selected persistent organic pollutants varied among the samples: PCBs (salmon, 145-460 ng/g lipid; salmon feeds, 76-1153 ng/g lipid; fish oils, 9-253 ng/g lipid), S DDTs (salmon, 5-250 ng/g lipid; salmon feeds, 34-52 ng/g lipid; fish oils, 11-218 ng/g lipid), and PBDEs (salmon, 1-85 ng/g lipid: salmon feeds, 8-24 ng/g lipid; fish oils, ND-13 ng/g lipid). Comparison of the samples for all groups of contaminants, except for HCHs, showed an increase in concentration in the order fish oil < feed < salmon. Homologue profiles were similar, with an increase in contribution of hepta- and octa-PCBs in the fish, and profiles of DDTs were similar in all three types of samples. With a constant contribution to the total PCB content, the ICES 7 PCBs appear to be reliable predictors of the PCB contamination profile through all the samples. For PBDEs, BDE 47 dominated the profiles, with no significant difference in the PBDE profiles for the three matrixes. Samples with higher PCB contents generally showed higher levels of the pesticide residues, but this was not the case with the PBDEs, indicating the existence of different pollution sources.     

Differentiation in the Lipid Quality of Wild and Farmed Seabass (Dicentrarchus labrax) and Gilthead Sea Bream (Sparus aurata)

ABSTRACT: The elements of differentiation that characterize the quality of the lipid fraction of wild and farmed sea bass (Dicentrarchus labrax) and gilthead sea bream (Sparus aurata) were investigated. Reared fish of either species had a total lipid content significantly higher than the wild counterparts. Liquid chromatography of unsaponifiable lipids showed, on a lipid gram basis, higher cholesterol levels in wild fish and comparable amounts of squalene, all‐trans retinol, and α‐tocopherol. Gas chromatography of total lipids revealed differences between the fatty acid profiles of wild and reared fish.     

Quality differences between heat-induced gels from farmed gilthead sea bream (Sparus aurata) and sea bass (Dicentrarchus labrax)

The effect of farmed fish species (sea bream, Sparus aurata, versus sea bass, Dicentrarchus labrax) on the quality of heat-induced gel products was evaluated. Additionally, the effect of microbial transglutaminase (MTGase) incorporation (0.5%, w/w) into the gels on their quality was also assessed.Both sea bream and sea bass yielded gel products of high quality. The fat content of the gel products attained from sea bass was higher than that of those prepared from sea bream (7.6% vs. 6.1%). Therefore, fat gels prepared with unwashed mince from farmed fish species may present a great potential for the aquaculture sector because, besides adequate gelling ability, these gels have a higher nutritional value than commercial gels, especially given their high eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) levels. Moreover, MTGase improved textural quality and reduced protein solubility. The gel strength, cohesiveness, and rupture properties of sea bream gels were higher than those of sea bass gels (mainly for gels containing MTGase), thus indicating a higher textural quality. Sea bass proteins were less soluble than sea bream proteins. Different hypothesis were put forward concerning the protein phenomena underlying such differences between the two farmed fish species.     

Effectiveness of ethanolic galangal extract (Alpinia galanga Linn.) on inhibition of lipid oxidation in fish muscle systems

Effectiveness of ethanolic galangal extract as an antioxidant in fish mince and fillet was investigated. The extract (5.8 μm gallic acid equivalent; GAE) reduced deoxygenation of sea bass haemoglobin (Lates calcarifer) at pH 6.5. The lag time for TBARs development in washed sea bass mince mediated by the haemoglobin at pH 6.5 was extended from 2 to 8 days by added galangal extract (0.02% w/w GAE). Washing the sea bass fillet with low preformed lipid hydroperoxide (LHP) content by galangal extract solution (0.2% w/v GAE) effectively inhibited the TBARs formation throughout the storage. However, in the longtail tuna fillet (Thunnus tonggol) having a significant content of preformed LHP, there was nonsignificant difference in the reaction lag time of the samples washed with the solution and with water. Thus, galangal extract can be used as an antioxidant in fish if its application is performed before initiation of lipid oxidation.     

Effects of high pressure treatment on physicochemical characteristics of fresh sea bass (Dicentrarchus labrax)

The effects of high pressure (HP) treatment (pressure: 220–250–330 MPA; holding time: 5 and 10 min; temperature: 3, 7, 15 and 25°C) on physicochemical characteristics (colour, thiobarbituric acid, trimethylamine nitrogen values) of fresh sea bass fillets were investigated. HP-treated sea bass fillets had higher lightness (Hunter L*) values than untreated sea bass fillets; the magnitude of changes increased with treatment pressure. HP-induced changes in colour generally imparted a cooked sample. The TBA value of HP treated sea bass samples (except 220–330 MPa, 3°C for 5 min) were found to be insignificant (P > 0.05) or significantly (P < 0.05) lower than the untreated samples. TMA-N content of HP treated at 220–250–330 MPa, 3–7–25°C for 10 min sea bass samples were found to insignificant according to the untreated samples. The results obtained from this study showed that the quality of high pressure treated sea bass is best preserved at 220 MPa, 25°C for 5 min.     

THE EFFECTS OF SEVERAL METHODS OF FISH PREPARATION ON RESIDUES OF POLYCHLORINATED BIPHENYLS AND SENSORY CHARACTERISTICS IN STRIPED BASS

Fifty striped bass were captured in Long Island Sound. The concentration of polychlorinated biphenyls (PCBs) was determined in the fish fillets before and after baking, boiling, frying, microwaving or poaching to study possible reduction of PCB residues by these cooking procedures. The cooked portions were evaluated for sensory characteristics. PCB content was significantly reduced by cooking, but there were no significant differences in that reduction among the six cooking methods. Tasters preferred fish prepared by "oil-based" cooking methods (bake, broil, fry) as compared to "water-based" methods (microwave, poach, boil).     

Quality Characteristics of Sea Bass Intensively Reared and from Lagoon as Affected by Growth Conditions and the Aquatic Environment

ABSTRACT: Sea bass ( Dicentrarchus labrax ) of commercial size free-living in the lagoon of Orbetello (Tuscany, Italy) and from intensive rearing were compared for proximate composition, essential and toxic metals, unsaponifiable lipids, and for the fatty acid profile of total, neutral, and polar lipids. Farmed sea bass had a total lipid content (10.57 ± 0.17g/100g) significantly higher (P ≤ 0.001) than fish in the wild (1.78 ± 0.01 g/100g). Fish from either productive systems showed comparably high total polyunsaturated fatty acid levels and n-3/n-6 ratio values. Differences in the mineral content occurred among fish, particularly in the levels of mercury and selenium, significantly higher in those from the lagoon.     

Effects of olive pomace and olive pomace oil on growth performance,fatty acid composition and cardio protective properties of gilthead sea bream (Sparus aurata) and sea bass (Dicentrarchus labrax)

Gilthead sea bream (Sparus aurata) and sea bass (Dicentrarchus labrax) were fed with two experimental diets: olive pomace diet and olive pomace oil diet, in order to examine whether fish oil substitution in fish feeds by olive oil production wastes, such as olive pomace and olive pomace oil, has an influence on growth performance, fatty acid composition and cardio protective properties of fish. Gilthead sea bream fed with both experimental diets exhibited satisfactory growth performance factors while sea bass did not. The total lipids of gilthead sea bream fed with olive pomace diet contained statistically decreased levels of fatty acids, while exhibited the most potent biological activity against platelet aggregation induced by Platelet Activating Factor. These data indicate that olive pomace can be used as a partial substitute of fish oil in fish feed improving its cardio protective properties.     

Antibiotics in South Indian coastal sea and farmed prawns (Penaeus monodon)

Sulphonamides and chloramphenicol antibiotics were analysed by using liquid chromatography–tandem mass spectrometry (LC-MS/MS) in sea and farmed prawn (Penaeus monodon) samples obtained from the coastal region of southern India during 2011–2012. Average recoveries were 77–99% and precision was between 1% and 8%. The results revealed that in sea prawn samples neither of the two antibiotics was detected, but in farmed samples from coastal Andhra Pradesh some sulphonamides were detected in a concentration range greater than the maximum residual limit as set by Council Directive 2377/90 EC.     

Comparison of wild and cultured sea bass (Dicentrarchus labrax) quality

Chemical composition, nutritional value and other physico-chemical parameters of sea bass from two different geographical areas (Greece and Spain) and from aquaculture and wild origin were studied. Farmed and wild fish differ in proximate composition, colour, and especially in texture, fatty acids and free amino acids (FAAs) profiles. Flesh of wild fish was firmer, which could be attributed to their lower fat content and higher level of activity. Cultured fish showed a higher content of monounsaturated fatty acids and lower of saturated and polyunsaturated fatty acids (PUFAs). Within the PUFA group, n−3 fatty acids were predominant in wild sea bass, while n−6 were more abundant in farmed fish. Some FAAs related to the characteristic flavour of fish, such as glutamic acid, aspartic acid, alanine, and glycine were more abundant in cultured sea bass. No differences between fish from both farms were found, due to the similar composition of the feed used.     

Effects of using slurry ice on the microbiological, chemical and sensory assessments of aquacultured sea bass (Dicentrarchus labrax) stored at 4 °C

Slurry ice, a biphasic system consisting of small spherical ice crystals surrounded by seawater at subzero temperature, was evaluated as a new chilled storage method for whole sea bass (Dicentrarchus labrax) a sparidae fish species of remarkable commercial interests. Four different group of chilling methods were used in this study; in slurry ice packaged on board (group A), in slurry ice packaged on company after 2 h (group B), slurry + flake ice packaged on board (group C) and only flake ice packaged on board (group D). The effect of this advanced system at the beginning of storage on quality losses and the shelf-life of aquacultured sea bass was evaluated. Mesophilic counts for sea bass exceeded 7 log cfu/g, which is considered the maximum level for acceptability for freshwater and marine fish after 13 days for groups C and D, and 15 days for groups A and B. At day 15; total volatile basic nitrogen (TVB-N) values of groups A–D reached the legal limits (35 mg/100 g set for TVB-N) for consumption. According to the results of sensory analyses, up to day 11, all the groups were determined as ‘acceptable’ but on day 13, the groups A–D were no longer acceptable. The main negative aspect related to quality loss in slurry ice group corresponded to the appearance of eyes and gills. Using slurry ice at the beginning of packaging did not affect the shelf-life of sea bass stored at 4 °C.