Determination of metal contaminations in sea foods from Marmara,Aegean and Mediterranean seas: Twelve fish species

The concentrations of cadmium, cobalt, chromium, copper, iron, manganese, nickel, lead and zinc were determined by ICP-AES in muscles and livers of 12 fish species sampled from the Marmara, Aegean and Mediterranean seas of Turkey. Iron showed the highest levels in examined tissues of all fish species. Following Fe, Zn generally showed the second highest levels. Metal concentrations in edible parts of fish species were 0.02–0.37 mg kg⁻¹ for cadmium, 0.04–0.41 mg kg⁻¹ for cobalt, 0.04–1.75 mg kg⁻¹ for chromium, 0.32–6.48  mg kg⁻¹ for copper, 7.46–40.1 mg kg⁻¹ for iron, 0.10–0.99  mg kg⁻¹ for manganese, 0.02–3.97 mg kg⁻¹ for nickel, 0.33–0.86 mg kg⁻¹ for lead, 4.49–11.2 mg kg⁻¹ for zinc, respectively. All metal concentrations in livers were higher than those in muscles. In some stations, cadmium and chromium concentrations in both muscles and livers, and lead levels in livers of the examined species were higher than permissible safety levels for human uses.     

Identification of some Aegean fish species by native isoelectric focussing

In this study, native protein patterns and band analysis of 20 Aegean and 2 North Atlantic fish species were obtained by isoelectric focussing (IEF) by determining their protein (in extract), TMA and TVB-N contents. Band specifications of the samples have been determined for comparing the different species of fish used as raw material. Aegean Sea has around 40 commercial fish species and 20 of them were taken into investigation. Building up a database for characterization of these species may help to find a way for further studies.     

Trace metal content in nine species of fish from the Black and Aegean Seas,Turkey

Trace metal content of nine fish species harvested from the Black and Aegean Seas were determined by microwave digestion and atomic absorption spectroscopy (MD–AAS). Verification of the MD–AAS method was demonstrated by analysis of standard reference material (NRCC-DORM-2 dogfish muscle). Trace metal content in fish samples were 0.73–1.83 μg/g for copper, 0.45–0.90 μg/g for cadmium, 0.33–0.93 μg/g for lead, 35.4–106 μg/g for zinc, 1.28–7.40 μg/g for manganese, 68.6–163 μg/g for iron, 0.95–1.98 μg/g for chromium, and 1.92–5.68 μg/g for nickel. The levels of lead and cadmium in fish samples were higher than the recommended legal limits for human consumption.     

Determination of metals in fish and mussel species by inductively coupled plasma-atomic emission spectrometry

The concentrations of cadmium, iron, lead, zinc, copper, manganese, nickel, chromium and cobalt were determined by ICP-AES in muscles, livers, gills and skins of two fish (Clarias gariepinus and Carasobarbus luteus), and in muscles and gills of two mussel species (Unio terminalis and Potamida littoralis) sampled from the Lake Gölba??. Iron showed the highest levels in all examined tissues of both fish species. Following Fe; Zn showed the second highest levels in all examined tissues of both fish species except Mn levels in muscle and gill of C. luteus. In both mussel species, to the contrary fish, manganese showed the highest levels in examined tissues, and followed by Fe. In both fish species, the all metal concentrations in livers were higher than those in muscles. Concentrations in tissues of the analyzed metals were significantly affected by species. There were differences between the metal levels in the similar tissues of the different species (p < 0.05). At the same time, there was also the differences between the metal concentrations in different tissues of the same species (p < 0.05). Metal levels in tissues were compared with national and international permissible limits. Metal concentrations in both edible and other tissues of the sampled species were within the permissible safety levels for human uses.     

Zinc and copper content in marine fish samples collected from the eastern Mediterranean Sea

Zinc and copper contents in the edible parts (muscle, fillet) of 49 commercially used fish species from the eastern Mediterranean Sea (Izmir Outer Bay, Homa Lagoon/Izmir and Mersin Bay) were determined by differential pulse stripping anodic voltammetry. In the sample preparation step, all frozen fish samples were lyophilized, milled in a ball mill and finally decomposed in an oxygen plasma ashing chamber. Among the three sampling locations, the highest zinc concentration was found in Mediterranean shad (Alosa fallax nilotica) from Izmir Outer Bay with 9.73 mg/kg wet weight and the highest copper content was found in derbio (Trachinotus ovatus) from Homa Lagoon with 1.14 mg/kg wet weight. The accuracy of the concentrations determined in this study was checked by the measurements of certified reference material no. 422 cod muscle from the Commission of the European Communities, Community Bureau of Reference. All zinc and copper concentrations observed in species of the eastern Mediterranean Sea showed that fish from this area are good sources of these essential elements.     

Determination of heavy metals (Cd,Pb) and trace elements (Cu,Zn) in sediments and fish of the Southeastern Aegean Sea (Turkey) by atomic absorption spectrometry

The Bay of Güllük in Southeastern Aegean Sea (Turkey) is very important by the potential of marine product in the Aegean Sea. There are various polluting elements in Güllük Bay. The current situation of the bay and impact of pollutants have became necessity. Dicentrarchus labrax are frequently used for human consumption. In this study, heavy metals (Pb, Cd) and trace elements (Cu, Zn) were analyzed in fish (D. labrax) and sediments in the Bay of Güllük by atomic absorption spectrometry. The average metal concentrations in the fish varied in the following ranges: Pb; <0.02–0.4, Cd; <0.01–0.04, Cu; <0.1, Zn; <0.5–7.2 mg kg⁻¹. In addition, seven sediment samples were analyzed and avarage concentrations of them were found as Zn; 80.8 ± 0.45, Cu; 25.2 ± 0.14, Pb; 20.0 ± 2, Cd; 0.560.08 mg kg⁻¹. The accuracy and precision of our results were checked by using International Certified Reference samples (fish: DORM-2, sediment: HISS-1).     

Determination of the lead and cadmium burden in some northeastern Atlantic and Mediterranean fish species by DPSAV

Lead (Pb) and cadmium (Cd) contents in the edible parts (muscle, fillet) of 68 commercially used fish species from two European regions, the northeastern Atlantic (Tampen, north of the Shetland Islands, Faroe Islands and Copinsay) and the Mediterranean (Izmir Outer Bay, Homa Lagoon/Izmir and Mersin Bay), were determined by means of differential pulse stripping anodic voltammetry. In the sample preparation step, all frozen fish samples were lyophilised, milled in a ball mill and finally decomposed in an oxygen plasma ashing chamber. Among the fishes from northeastern Atlantic waters, the highest average Pb concentration belonged to those from Tampen with 11.25 µg/kg and the average Cd concentration to fish from Copinsay with 2.23 µg/kg. For the Mediterranean fishes, the highest average Pb and Cd concentrations belonged to those from Mersin Bay, with 185.39 µg/kg and 2.12 µg/kg, respectively. The accuracy of the concentrations determined in this study was checked by measurements of the certified reference material CRM No 422 cod muscle from the Commission of the European Communities, Community Bureau of Reference. All Cd and Pb concentrations observed in species of the eastern Mediterranean and the northeastern Atlantic were below the maximum permitted national Turkish and European levels.     

Monitoring of perfluorinated compounds in edible fish from the Mediterranean Sea

Perfluorooctanoic acid (PFOA) and perfluorooctane sulphonate (PFOS) are environmental contaminants belonging to a chemical group known as perfluorinated compounds (PCFs). The United States Environmental Protection Agency (US EPA) considers both compounds to be carcinogenic. The goal of the present study was to evaluate the contamination levels of PFOS and PFOA in edible fish of the Mediterranean Sea. Twenty six fish muscles, 17 fish livers, five series of cephalopods (each composed of ten specimens) and thirteen series of bivalves (each composed of about 50 specimens) were used for the investigation. A fast sample treatment, followed by an LC–ESI–MS/MS method is described for the identification, and quantification of PFOA and PFOS in fish. The method was in-house-validated through the determination of precision, accuracy, specificity, calibration curve, decision limit (CCα), and detection capability (CCβ). The results showed PFOA and PFOS levels in fishes and molluscs lower than those reported for analogue matrices in different geographic areas. Therefore, our biomonitoring results did not show that the Mediterranean Sea had any particularly alarming pollution by PFCs, although it is located in a semi-closed basin with scarce water change. Nonetheless, a worrying element is that a few fish showed extremely high contamination by PFOA and PFOS. This finding needs further clarification in order to assess whether such unusual contamination is linked to “dot-like” pollutant release, which could explain the anomaly.     

Fatty acid profiles of commercially important fish species from the Mediterranean, Aegean and Black Seas

The fat content and fatty acid compositions in the flesh of eight commercially important fish species from the seas of Turkey were evaluated. The fatty acid compositions of wild fish species ranged from 25.5% to 38.7% saturated (SFA), 13.2–27.0% monounsaturated (MUFAs) and 24.8–46.4% polyunsaturated acids (PUFAs). Among them, those occurring in the highest proportions were myristic acid (C14:0, 1.70–10.9%), palmitic acid (C16:0, 15.5–20.5%), palmitoleic acid (C16:1, 2.86–17.0%), stearic acid (C18:0, 3.32–8.18%), oleic acid (C18:1n9 cis, 6.11–20.8%), linoleic acid (C18:2n6, 0.93–4.03%), octadecatetraenoic acid (C18:4n3, 0.02–4.55%), cis-5, 8, 11, 14, 17-eicosapentaenoic acid (EPA, C20:5n3, 4.74–11.7%) and cis-4, 7, 10, 13, 16, 19-docosahexaenoic acid (DHA, C22:6n3, 7.69–36.2%). The proportions of PUFAs-n3 (ranging from 21.7 for mullet to 43.7 for scad) were higher than those of PUFAs-n6 (ranging from 1.24 for bogue to 4.34 for red scorpion fish). EPA and DHA were high in all fish species, increasing the value of these fish species.     

Production and quality of fish fingers from different fish species

Abstract Production of fish fingers was achieved by using fish species such as sardine (Sardina pilchardus, Walbaum, 1792), whiting (Merlangius merlangus, Linnaeus, 1758) and pike perch (Sander lucioperca, Linnaeus, 1758). Quality changes of battered fish patties during a period of 8 months at –18 °C were investigated. According to the results of microbiological and chemical analysis, fish fingers were found to be within acceptable limits during frozen storage for 8 months. However, sensory analysis showed that, at the end of the frozen storage, fish fingers made from sardine could not be consumed because of rancidity.     

Heavy metal concentrations in fish,shellfish and fish products from internal markets of India vis-a-vis international standards

Heavy metals are an important group of chemical contaminants and food is the major vehicle for entry into the system. Fish constitute a major source of heavy metals in food. Concentration of heavy metals in commercially important species of fish, shellfish and fish products from fish markets in and around the Cochin area was evaluated using an atomic absorption spectrometer. The concentration ranges of Cd, Pb, Hg, Cr, As, Zn, Cu, Co, Mn, Ni, and Se in the samples were <0.07–1, <0.07–1.32, <0.05–2.31, <0.05 to 3.65, <0.1–4.14, 0.6 to 165, 0.15 to 24, <0.02 to 0.85, <0.08 to 9.2, <0.032–1.38 and; <0.03–1.35 mg/kg, respectively. The present study showed that different metals were present in the samples at different levels but within the maximum residual levels prescribed by the EU and USFDA and the fish and shellfish from these areas, in general, are safe for human consumption.     

Seasonal evaluation of nutritional benefits of two fish species in the eastern Mediterranean Sea

Fish are a good nutritional source of proteins, essential fatty acids and minerals. Societies with high fish intake have lower rates of acute myocardial infarctions and atherosclerosis, better cognitive functions, and better neural and visual development in foetuses. In the present work, we evaluated seasonal variation in proximate composition of two commercial fish species, the rabbitfish Siganus rivulatus, an algaevore, and the white sea bream Diplodus sargus, a carnivore from the eastern Mediterranean. Fifteen fish were collected on the second weekend of each of 8 months covering the four seasons. Results show that the nutritive value of a species of fish varies throughout the year. Furthermore, rabbitfish tissue generally contains more lipids than white sea bream, and fillet yield from rabbitfish is greater than from sea bream. As both fish are sold at a similar price in Lebanese markets, results suggest that rabbitfish offers better value for the price than does white sea bream.     

Determination of trace metal levels in sediment and five fish species from lakes in Tokat,Turkey

In this study, concentrations of trace metals in five fish species (Cyprinus carpio, Capoeta tinca, Leiciscus cephalus, Carassius gibelio and Silurus glanis) and sediments collected from some lakes in Tokat were determined by atomic absorption spectrometry. The fish species and sediment samples were collected from six lakes (Bedirkale, Boztepe, Belp?nar?, Avara, Ataköy and Ak?n) in Tokat, Turkey in spring and summer during 2003–2004. The samples were digested with a microwave digestion system. The maximum Fe, Mn, Zn, Cu, Pb, Cr and Ni concentrations of sediment samples were 2138, 232, 38.9, 8.2, 7.0, 10.7 and 55.4 μg/g, respectively. The maximum Fe, Zn, Cu, Pb, Cr, Mn and Ni concentrations of the fish samples were 167, 48.6, 3.6, 2.8, 1.6, 64.3 and 5.6 μg/g, respectively.     

Heavy metals in marine fish meat and consumer health: a review

The numerous health benefits provided by fish consumption may be compromised by the presence of toxic metals and metalloids such as lead, cadmium, arsenic and mercury, which can have harmful effects on the human body if consumed in toxic quantities. The monitoring of metal concentrations in fish meat is therefore important to ensure compliance with food safety regulations and consequent consumer protection. The toxicity of these metals may be dependent on their chemical forms, which requires metal speciation processes for direct measurement of toxic metal species or the identification of prediction models in order to determine toxic metal forms from measured total metal concentrations. This review addresses various shortcomings in current knowledge and research on the accumulation of metal contaminants in commercially consumed marine fish globally and particularly in South Africa, affecting both the fishing industry as well as fish consumers. © 2015 Society of Chemical Industry     

Essential elements and contaminants in tissues of commercial pelagic fish from the Eastern Mediterranean Sea

BACKGROUND: It is important to determine the concentrations of essential and non‐essential metals in fish for human health. The essential elements and contaminants (Pb and Cd) were determined seasonally in the muscle and liver of some pelagic fish species round herring (Etrumeus teres), chub mackerel (Scomber japonicus), golden grey mullet (Liza aurata) and Mediterranean horse mackerel (Trachurus mediterraneus) from the Iskenderun Bay, Eastern Mediterranean Sea. RESULTS: The Na, K, Ca and Mg were the most abundant elements in muscle and liver tissues. The Na, K, Ca and Mg concentrations in fish tissues were between 51.7 and 3426 mg kg^?1. Muscle accumulated the lowest levels of elements. Trace element and contaminant levels in muscle were highest in spring and summer. The Cu, Zn and Cr concentrations were highest in summer. The Ni, Mn and Fe concentrations were highest in spring. The maximum Pb concentrations in the muscle and liver of fish species was 0.39 and 0.80 mg kg^?1 in autumn. The maximum Cd concentration in the muscle of fish was 0.27 mg kg^?1 in spring and the maximum Cd concentration in the liver was 0.78 mg kg^?1 in summer. CONCLUSION: The Cr, Pb, Cd, Cu and Zn levels in muscle were found to be lower than permissible limits reported by various authorities. Estimated weekly and daily intake for Pb and Cd by consumption of fish muscle were far below the PTWI and PTDI values established by FAO/WHO. Copyright © 2009 Society of Chemical Industry     

Determination of inorganic arsenic species (As and As) in muscle tissues of fish species by electrothermal atomic absorption spectrometry (ETAAS)

Arsenic speciation was carried out in muscle tissues of freshwater fish species. Inorganic arsenic species (As³⁺and As⁵⁺) were extracted with chloroform, prior to microwave assisted digestion with concentrated HClO₄ and Fe₂(SO₄)₃. The extracted As³⁺ and As⁵⁺ were determined by electrothermal atomic absorption spectrometry (ETAAS). The accuracy of the technique was evaluated by using certified reference material DORM-2. The limit of detection of the method was 0.004 and 0.005 μg/g for As³⁺ and As⁵⁺, respectively. The mean relative standard deviation values (RSD) in real sample analysis were 1.90 and 3.92 for As³⁺ and As⁵⁺, respectively. The results demonstrated the suitability of the procedure for screening and quantification of As species in biological samples. The mean concentration of As³⁺ and As⁵⁺ in muscle tissues of studied fish species ranged from 1.19 to 2.05 and 0.17 to 0.46 μg/g, respectively. The contribution of the daily intake of inorganic As, based on the consumption of 250 g fresh fish muscles/body weight/day was found in the range of 1.21–1.91 μg/kg/day.     

Heavy metals in three commercially valuable fish species from İskenderun Bay,Northern East Mediterranean Sea,Turkey

Concentrations of cadmium, iron, lead, zinc, copper, manganese, nickel, chromium, cobalt and aluminum were determined in three commercially valuable fish species, Saurida undosquamis, Sparus aurata, Mullus barbatus, from İskenderun Bay in August 2003. The concentration of metals was measured by atomic absorption spectrophotometry (AAS). Concentrations of the heavy metals in examined fish species ranged as follows: Cd 0.01–4.16; Fe 0.82–27.35; Pb 0.09–6.95; Zn 0.60–11.57; Cu 0.04–5.43; Mn 0.05–4.64; Ni 0.11–12.88; Cr 0.07–6.46; Co 0.03–5.61; Al 0.02–5.41 mg kg⁻¹ dry weight, respectively. The concentration of metals was significantly affected by the sampling site and fish species. Heavy metals in the edible parts of the investigated fish were in the permissible safety levels for human uses.     

Determination of ascorbic and dehydroascorbic acid in lean and fatty fish species by high-performance liquid chromatography with fluorometric detection

Ascorbic acid (AA) and dehydroascorbic acid (DHAA) were analysed in fish muscle by high performance liquid chromatography (HPLC) coupled with fluorescence determination using 4,5-dimethyl-o-phenilenediamine (DMPD) as a derivative agent. The use of the DMPD in combination with isobutanol extraction eliminated many matrix interferences and increased significantly the specificity and sensitivity of the method. A strong pH dependence in the derivatization reaction was also demonstrated. Satisfactory results in terms of sensitivity, stability and reproducibility were obtained. The analyses demonstrated that the relative ratio of AA and DHAA in post-mortem fish muscle differs among fish species and seems to be related with the susceptibility to oxidation.     

Metals and other elements in tissues of wild fish from fish farms and comparison with farmed species in sites with oxic and anoxic sediments

Farmed fish and wild fish aggregating in the vicinity of four Mediterranean fish farms with different environmental conditions were sampled. Levels of metals (including As and Se) were measured in the muscle, liver, gills, bone and intestine. The wild fish from sites with anoxic substrata accumulate metals (including As and Se) from the ambient habitat in their gills whereas those from sites with oxic substrata concentrate these elements through their diet in their intestine. Tissues of wild fish aggregating around farm cages accumulate a greater number of these elements and with higher concentrations than farmed fish. Habitat, diet, ecological needs, fat content of fish, and protein expression may play an important role in these element differences between fish species. Fe in flathead grey mullet, As in surmullet, rainbow wrasse, grey gurnard and picarel and Hg in bogue may pose a risk for human health. Farmed and wild fish are good sources of P, K, Cr and Se while flathead grey mullet, picarel and comber are excellent sources of Ca and Se.