Non-dioxin-like PCBs: a survey on fishery and aquaculture from the Mediterranean area

A sampling campaign from 21 sites in Italy was conducted: 15 species from fishery and three species from aquaculture, for a total of 40 determinations, were considered. A careful sample preparation preceded the instrumental analysis that was carried out by means of GC–ECD and GC–MS. Good laboratory practice was achieved by the participation in proficiency tests, by the use of certified reference materials and by applying other directives recommended by international organisations. Concentrations measured in this work were compared with a TDI proposed by some international bodies: for a person weighing 70 kg one-third of the samples from fishery, when consumed, lead to exceed this TDI if the average fish daily consumption per capita is considered. Based on the data obtained here some hypotheses on environmental spreading and influence of PCBs on human health are made. Some suggestions about the preparation of fish for consumption are also given.     

Nutritional and commercial quality of the striped venus clam, Chamelea gallina, from the Adriatic sea

Nutritional quality parameters (proximate and mineral composition, contents of glycogen, fatty acids, cholesterol, plant sterols, fat-soluble vitamins, carotenes) and ecophysiological and commercial quality indicators (Condition Index, percent content of meat and intervalvar fluid) of the striped venus clam, Chamelea gallina, from the central Adriatic coast of Italy were studied at seasonal intervals over a 1-year period. Contents of protein (8.55–10.7 g/100 g), total lipid (0.73–1.59 g/100 g), glycogen (2.25–4.96 g/100 g) and non-protein nitrogen (0.54–0.78 g/100 g) varied significantly during the year, reaching the highest values in winter, in coincidence with a peak of Condition Index. Gas chromatography of total lipids showed high percentages of n − 3 polyunsaturated fatty acids (33.7–41.9% of total fatty acids), in particular eicosapentaenoic (8.16–20.0% of total fatty acids) and docosahexaenoic acids (12.5–20.3% of total fatty acids) and low levels of total n − 6 polyunsaturated fatty acids (3.61–7.87% of total fatty acids). HPLC analysis of the unsaponifiable lipids showed low levels of cholesterol, the dominant sterol (28.3–34.2 mg/ 100 g), and variable amounts of plant sterols (stigmasterol + campesterol, β-sitosterol, fucosterol + brassicasterol), α-tocopherol and carotenes.     

Growth,nutritional quality and safety of oysters (Crassostrea gigas) cultured in the lagoon of Venice (Italy)

Quality aspects of oysters (Crassostrea gigas) from a suspended culture in the lagoon of Venice (Valle Dogà) were examined in different seasons over a 1‐year period. Ecophysiological and commercial quality indicators (condition index, content of meat, shell and intervalvar fluid), nutritional quality parameters (proximate and mineral composition, glycogen content, fatty acid profile, cholesterol, plant sterols, fat‐soluble vitamins content) and levels of organic pollutants (polychlorinated biphenyls and organochlorine pesticides) were determined at different times of the year. Seasonal variations were observed in the nutrient content, with particular regard to moisture (ranging from 866.8 g kg^?1 in June to 938.8 g kg^?1 in September), protein (23.9 g kg^?1 in September to 76.6 g kg^?1 in June), ash (22.5 g kg^?1 in February to 29.5 g kg^?1 in July), lipid (3.0 g kg^?1 in September to 8.8 g kg^?1 in June) and glycogen (0.7 g kg^?1 in September to 11.5 g kg^?1 in February). In spite of this variability, the nutritional quality of the oysters was generally good, especially just before gamete release when the concentration of nutrients was at its maximum. Low levels of organochlorine chemicals were detected in the edible meat of oysters but, because only a limited number of samples were analysed, no general conclusion can be drawn on the safety of seafood from this area. Copyright © 2004 Society of Chemical Industry     

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.     

Nutritional quality and safety of European perch (Perca fluviatilis) from three lakes of Central Italy

European perch (Perca fluviatilis) harvested from three lakes of Central Italy were studied in different seasonal periods of a year to evaluate their nutritional quality and some safety aspects related to the pollution of the aquatic environment. The lakes considered, located in the Latium region, differed with respect to their volcanic (Bolsena and Bracciano Lakes) or artificial (Salto Lake) origin. Fillets of fish caught in the three lakes were characterised by good protein (17–19%) and mineral contents and low lipid levels (0.6–1.2%) throughout the year. Total lipids were characterised by low cholesterol levels (41.9–74.7 mg/100 g) and high percentages of total n − 3 polyunsaturated fatty acids (27.7–33.8% of total fatty acids), in particular docosahexaenoic acid (14.2–25.3% of total fatty acids). The qualitative analysis of the stomach content of perch confirmed their predatory feeding behaviour. The chemical and nutritional profiles of perch from the three lakes were comparable except for rubidium and cesium levels, which were higher in the muscle tissues of perch from the volcanic lakes. These minerals may represent elements of traceability of the origin of fish. Low levels of organochlorine pesticides and polychlorinated biphenyls, well below the Italian and European action limits, were detected in the muscle tissue of perch from all three lakes.     

Total volatile basic nitrogen and trimethylamine nitrogen levels during ice storage of European hake (Merluccius merluccius): A seasonal and size differentiation

Whole ungutted European hake (Merluccius merluccius) caught by trawling off the Central Tyrrhenian coast of Italy in winter and in summer were stored in ice. The dynamics of changes of total volatile basic nitrogen (TVB-N) and trimethylamine-nitrogen (TMA-N) levels during ice storage of small- (20 ± 3 cm length) and large-sized (37 ± 6 cm length) hake caught in either season were studied. The TVB-N and TMA-N levels of hake caught in winter remained low (below 20 mg and 3 mg/100 g, respectively) throughout the experiment regardless of the body size. In summer TVB-N and TMA-N levels increased sharply (P < 0.05) during ice storage and at a higher rate in small than in large fish, a fact ascribable to fish exposure to high temperatures first in the water, during trawling, and then in the fishing vessel before ice-boxing. On the basis of the results obtained in this work, it may be concluded that ungutted European hake show a clear seasonal and size differentiation of the evolution of TVB-N and TMA-N during ice storage.     

Analysis of Fatty Acids in 12 Mediterranean Fish Species: Advantages and Limitations of a New GC-FID/GC–MS Based Technique

When fatty acids in fish are analyzed, results in percentage form (profile analysis) are mostly reported. However, the much more useful results expressed as mg/100 g (absolute analysis) is the main information required. Absolute methods based on calibration curves are of good accuracy but with a high degree of complexity if applied to a great number of analytes. Procedures based on the sequence profile analysis–total FA determination–absolute analysis may be suitable for routine use, but suffer from a number of uncertainties that have never been really resolved. These uncertainties are mainly related to the profile analysis. In fact, most profile analyses reported in the literature disagree about the number and type of fatty acids monitored as well as about the total percentage to assign to their sum so leading to possible inaccuracies; in addition the instrumental response factor for all FAME (fatty acid methyl esters) is often considered as a constant, but this is not exactly true. In this work, a set of 24 fatty acids was selected and studied on 12 fish species in the Mediterranean area (variable in lipid content and month of sampling): in our results, and in these species, this set constitutes, on average, 90 ± 3 % of the total fatty acid content. Moreover the error derived from the assumption of a unique response factor was investigated. Two different detection techniques (GC-FID and GC–MS) together with two capillary columns (different in length and polarity) were used in order to acquire complementary data on the same sample. With the protocol here proposed absolute analyses on the 12 cited species are easily achievable by the total FA determination procedure. The accuracy of this approach is good in general, but in some cases (DHA for example) is lower than the accuracy of calibration-based methods. The differences were evaluated on a case by case basis.     

Current Advances in 3D Tissue and Organ Reconstruction

Bi-dimensional culture systems have represented the most used method to study cell biology outside the body for over a century. Although they convey useful information, such systems may lose tissue-specific architecture, biomechanical effectors, and biochemical cues deriving from the native extracellular matrix, with significant alterations in several cellular functions and processes. Notably, the introduction of three-dimensional (3D) platforms that are able to re-create in vitro the structures of the native tissue, have overcome some of these issues, since they better mimic the in vivo milieu and reduce the gap between the cell culture ambient and the tissue environment. 3D culture systems are currently used in a broad range of studies, from cancer and stem cell biology, to drug testing and discovery. Here, we describe the mechanisms used by cells to perceive and respond to biomechanical cues and the main signaling pathways involved. We provide an overall perspective of the most recent 3D technologies. Given the breadth of the subject, we concentrate on the use of hydrogels, bioreactors, 3D printing and bioprinting, nanofiber-based scaffolds, and preparation of a decellularized bio-matrix. In addition, we report the possibility to combine the use of 3D cultures with functionalized nanoparticles to obtain highly predictive in vitro models for use in the nanomedicine field.     

New trends in the seafood market. Sutchi catfish (Pangasius hypophthalmus) fillets from Vietnam: Nutritional quality and safety aspects

Sutchi catfish (Pangasius hypophthalmus) produced in the freshwater basins of Vietnam, available on the Italian market as frozen or thawed fillets, were studied for their nutritional quality and safety aspects. Proximate composition, mineral content, fatty acid profile, unsaponifiable components of the lipid fraction and drip loss during thawing at 5 °C were determined on the fillets. Fillets were characterised by high moisture levels (80–85%) and low protein (12.6–15.6%) and lipid (1.1–3.0%) contents. Total lipids were characterised by low cholesterol levels (21–39 mg/100 g), high percentages of saturated fatty acids (41.1–47.8% of total fatty acid) and low percentages of polyunsaturated fatty acids (12.5–18.8% of total fatty acids), which were mainly represented by linoleic acid (44–59% of total polyunsaturated fatty acids). The mineral composition was characterised by a high sodium content (222–594 mg/100 g), probably partially due to the sodium tripolyphosphate (E 451) used to retain moisture. As regards safety aspects, the quality of the samples analysed was good, with low residue levels of mercury, organochlorine pesticides and polychlorinated biphenyls.     

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.