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A key requirement for the successful implementation of the Landing Obligation is the need to monitor and regulate unwanted catches at sea. This issue is particularly challenging because of the large number of vessels and trips that need to be monitored and the remoteness of vessels at sea. Several options exist in theory, ranging from patrol vessels to onboard observers and self-sampling. Increasingly though, technology is developing to provide remote Electronic Monitoring (EM) with cameras at lower costs. This chapter first provides an overall synthesis of the pro’s and con’s of several monitoring tools and technologies. Four EM technologies already trialled in EU fisheries are then summarised. We conclude that it is now possible to conduct reliable and cost-effective monitoring of unwanted catches at sea, especially if various options are used in combination. However, effective monitoring is a necessary condition for the successful implementation of the Landing Obligation but insufficient unless it is implemented with a high level of coverage and with the support of the fishing industry

The progressive elimination of fish discards established by the European Union Council in 2013 has stimulated the valorization of flesh from discarded high-quality species with good protein functional properties but which frequently have excessive fish-bones, fat, strange flavours, soft texture, etc. The present study therefore focuses on valorization of the extracted muscle (minced muscle), from several fish species frequently discarded in north-western Spanish fisheries (Atlantic Ocean): Blue whiting (Micromesistius poutassou), Mackerel (Scomber scombrus), Red scorpionfish (Scorpaena scrofa), Pouting (Trisoreptus luscus) and Gurnard (Trigla spp.). Valorization of these discarded fish resources is a key objective for the survival of the fishery sector in this area. In this regard present study was planned to examine the behaviour of the mince during 6 months of frozen storage by means of physicochemical and sensory analyses, and to test consumer acceptance of three technologically different products (burgers, nuggets and structured fingers) prepared with fish mince from different species. Results indicated that protein aggregation started at the outset of frozen storage but progressed very slowly, with the exception of non-washed blue whiting and red scorpionfish minces. Moreover, during frozen storage lipid oxidation increased in all samples; the increase was with two objectives highest in minced mackerel, a fatty fish, but no rancid flavour was detected. All mince samples presented acceptable physicochemical properties and good sensory acceptability after 6 months of frozen storage. Acceptability of final products made with these minces was high in all cases. Burgers were more acceptable for consumers aged over 40 and fingers and nuggets more for younger people

The polymerase chain reaction (PCR) technique was employed to obtain a 464 bp amplicon from the mitochondrial cytochrome b gene from gadoid species to study its ability to differentiate them. The sequences of this fragment from 16 species were analysed using a genetic distance method, and polymorphic sites were determined. The fragment was shown to be moderately polymorphic (151 sites), and this permitted the differentiation of most of the species. A phylogenetic tree construction using Tamura-Nei distances was employed to allow the identification of Gadidae species, each species resulted in a well-differentiated clade, with the exception of Gadus ogac and Gadus macrocephalus, which could not be differentiated. Based on the sequences obtained, three restriction enzymes, Dde I, Hinc II and Nla III, were selected to provide specific restriction profiles, which allowed the differentiation of 15 species of gadoids in a faster and less expensive way than sequencing. The PCR-restriction fragment length polymorphism methodology was also tested using commercial samples.

Identification of commercial species is a relevant issue to assure the correct labeling of seafood products. In this work two different molecular techniques, FINS (Forensically Informative Nucleotide Sequencing) and PCR-RFLP (Polymerase Chain Reaction-Restriction Fragment Length Polymorphism) were developed to identify 8 cephalopod species (families Loliginidae and Ommastrephidae) employing a fragment of the cytochrome b gene. DNA amplification for all of the species was carried out with a new set of specific primers designed in this study for cephalopods. FINS is a technique based on DNA sequencing, while PCR-RFLP allows direct species identification by comparing specific DNA restriction patterns. Both techniques are useful for cephalopod species identification. 17 food products (mainly “squid rings”) were analyzed and the species employed for their manufacture identified by FINS.

PCR-based methods have been developed to differentiate four species of commercially important eels (Anguilla anguilla, A. rostrata, A. japonica, A. australis). By means of universal primers a 464 base pair (bp) section of the cytochrome b gene was amplified. The amplicon was sequenced and restriction enzymes were selected for RFLP analysis; a short part (123 bp) of the 464 bp section was amplified by another set of primers and used for SSCP analysis. The suitability of RFLP and SSCP for differentiating hot-smoked eel was verified by a collaborative study

The use of a PCR-RFLP based method for the identification of salmon species in food products was investigated. The reliability and practicality of the method was tested by a collaborative study in which five European laboratories participated. Two unknown samples (a commercial product of known species composition and a mix of two salmon species) required identification by comparison with authentic reference species. From a total of 50 cases, 100% of authentic species were correctly assigned, with all unknown samples also correctly identified. A larger scale analysis of UK commercial products was also performed spanning the whole range of salmon products available. In almost all cases the salmon species declared was confirmed, although, a trout species was detected in one product declaring only the presence of salmon. The investigation confirms the reproducibility of the method in different laboratories, and its applicability for commercial product analysis.

A simple and rapid method to identify raw or frozen gadoid fish species is described. The methodology is based on the HPLC separation of water-soluble proteins and monitoring at 230 nm. Chromatographic profiles were reproducible between individuals belonging to the same species; lower variations in the relative retention time than in peak area percentage were observed. Results obtained from an ANOVA test allowed the distinction of characteristic peaks. Profiles were independent of fish quality: fish refrigerated for 10 days showed the same HPLC protein profile as those that were fresh. The ability of the identification procedure was checked by analysis of a set of frozen commercial samples.

Histamine levels in samples of Þsh and marine products were determined by capillary zone electrophoresis using phosphate bu¤er at pH 2.44 and UV detection at 214 nm. A plot of the area of the peaks versus histamine concentration was linear over the range of 1Ð100 ppm with a correlation coe¦cient of 0.9996. Calibration using the height of the peak also gave good correlation, with a correlation coe¦cient of 0.9969, at concentrations between 1 ppm and 20 ppm. The recovery of added histamine in di¤erent samples of Þsh and Þsh products was, on average, 99.65%. The method described in this work was used for the quantitation of histamine in Þsh and Þsh products.

A comparative study of the phospholipids of white muscle of six of the comercially utilized tuna species, including quantitative analyses of phospholipid classes and studies of the acyl composition of the major components. Plasmalogen compounds also were identified and quantified. Choline and ethanolamine glycerophospholipids were the most abundant classes in all the samples, as well as the only molecules containing plasmalogens (16∶0, 18∶0, and 18∶1 alkenyl ether chains). The patterns of fatty acid distribution within each of the phospholipid classes showed general similarities in the species analyzed. However, ratios between certain saturated and polyunsaturated fatty acids in different phospholipid classes showed remarkable diffences. The high content of n−3 polyunsaturated fatty acids in the principal phospholipids, such as the plasmalogens, and taking into account the fatty acids possible importance in human nutrition, indicates that the white muscle of tuna species may be a potentially important dietary item.

[EN] Proteins of fish muscle undergo chemical and physical changes during frozen storage which may result in, under certain conditions (i. e. long periods of storage, poor freezing practices, temperature fluctuations, etc), loss of quality, reflected mainly by an unacceptable texture as well as an undesirable flavour, odour and colour. In frozen gadoid fish species, most of these changes are caused by the production of formaldehyde in the muscle. Formaldehyde is produced, along with dimethylamine, by the enzymatic reduction of trimethylamine oxide (TMAO). Many aspects of formaldehyde production by TMAO demethylase (TMAOase) have been studied throughout the last decade. In addition, different approaches have been used to investigate the effect of formaldehyde production on protein denaturation and the associated muscle textural changes. Some insight into the reaction between protein and formaldehyde has clarified the possible mechanism of formaldehyde-mediated denaturation. However, evidence of covalent bonding between proteins and formaldehyde, to form crosslinks, has not explained fully the changes observed in fish proteins during frozen storage. The study of cold-induced denaturation of proteins might give new clues for further investigation of the problem. The implications of formaldehyde in toxicological and nutritional issues is also reviewed, as general concern about the safety of food products is a growing field in food science. Finally, different approaches have been proposed to avoid the detrimental action of formaldehyde during frozen storage of gadoid fish; they are some of the practical applications of the knowledge acquired after years of study of different workers in the field., [DE] Die Proteine des Fischmuskels unterliegen während der Gefrierlagerung chemischen und physikalischen Veränderungen, die unter gewissen Bedingungen (lange Lagerzeiten, mangelnde Gefriertechniken, Temperaturschwankungen usw.) zu einem Verlust an Qualität führen können, was sich hauptsächlich in nicht akzeptierbarer Konsistenz und unerwünschten Aromen, Farben und Gerüchen manifestiert. In tiefgefrorenen Gadiden (Kabeljauartigen) werden die meisten dieser Veränderungen durch die Entstehung von Formaldehyd (FA) im Muskel hervorgerufen. FA wird, zusammen mit Dimethylamin (DMA), durch die enzymatische Reduktion von Trimethylaminoxid (TMAO) gebildet. Während der letzten Dekade wurden viele Aspekte der Bildung von FA aus TMAO untersucht. Verschiedene Versuche zur Aufklärung des Effektes der FA-Bildung auf die Proteindenaturierung und die damit verbundenen Veränderungen der Muskelkonsistenz wurden unternommen. Einige Einblicke in die FA-Protein-Reaktionen haben den möglichen Mechanismus der durch FA bewirkten Denaturierung erhellt. Die wahrscheinlich vorliegenden kovalenten Bindungen zwischen Proteinen und FA, die als Quervernetzungsbildner agieren, konnten aber die Veränderungen, die in Fischproteinen während der Gefrierlagerung beobachtet werden, nicht vollständig erklären. Die Untersuchung der Kältedenaturierung von Proteinen könnte neue Anhaltspunkte für eine weiter Untersuchung dieses Systems geben. Die Beteiligung von FA bei toxikologischen und ernährungswissenschaftlichen Fragestellungen wird ebenfalls kritisch betrachtet. Letztlich werden verschiedene Möglichkeiten vorgeschlagen, um die schädliche Wirkung von FA während der Gefrierlagerung von Gadiden zu verhindern

[EN] The damage to tuna fish lipids induced by cooking was investigated in theThunnus obesus andTh. thynnus varieties, using conventional and fluorescence detection methods, and the results were compared. As a consequence of thermal processing, the peaks at longer wavelengths increased, which correlated with other conventional indices of lipid damage (i.e. carbonyl compound formation, browning and increases in the free fatty acid content). A special significance was given to the fluorescence ratio between the maxima of the excitation emission data at 393/460 nm and 327/415 nm; increases in this ratio as a result of cooking were less dependent on the samples than were other conventional methods of measuring lipid damage., [DE] Lipidschäden während des Abkochens von zwei Thunfisch-Arten (Thunnus obesus undTh. thynnus) wurden untersucht. Fluorescenzmeßungen in verschiedenen Wellenlängenbereichen wurden mit anderen Methoden verglichen, die zur Bestimmung von Lipidschäden gebraucht werden. Als Ergebnis der Wärmebehandlung wurde eine Fluorescenzverschiebung zu höheren Wellenlängenmaxima offenbar; gleichzeitig zeigten die Qualitätskriterien eine verstärkte Lipidschädigung (Carbonylbildung und Bräunungsentwicklung sowie Zunahme von freien Fettsäuren). Die Fluorescenzverhältnisse zwischen 393/460 nm und 327/415 nm (Maxima) zeigten weniger Abhängigkeit von den Proben als andere Lipidschädenmessungen.

[ES] The kinetics of thermal degradation of thiamine and surface colour (lightness measured as Hunter L-value) in canned white tuna were determined using an unsteady-state experimental procedure. Kinetic parameters were calculated by weighted non-linear regression considering a first-order kinetic model with a dependence of the kinetic coefficient (D) with temperature of the Thermal Death Time (TDT) type. Mass-average retentions of thiamine were calculated using a mathematical model which takes into account the non-uniform and unsteady distribution of temperature inside the container during thermal processing. The high correlation obtained between the predicted and the observed retention values and the small confidence intervals found for the kinetic parameters indicate a high statistical reliability. The kinetic model thus determined permits the simulation and optimization of the process resulting in a better quality of the final product., [DE] Die Kriterien der Wärmedegradation von Thiamin und der Oberflächenfarbe (Messung der Helligkeit mit dem Hunter-Wert L) in Konserven mit weißem Thunfisch werden mittels eines experimentellen Vorgehens von nicht-stationärem Typ bestimmt. Die kinetischen Parameter werden mit nicht-linearer, beschwerter Regression kalkuliert, wobei man einen kinetischen Koeffizienten D mit der Temperatur des Typs TDT bedenken muß. Für die Berechnung der durchschnittlichen Massenerhaltung von Thiamin benutzt man ein mathematisches Modell, das die nicht-uniforme und nichtbeständige Verteilung der Temperatur im Behälter während des Prozesses berücksichtigt. Die erhaltene starke Wechselbeziehung zwischen den vorhergesagten und den beobachteten Werten und zwischen den geringen Konfidenz-Intervallen, die für die kinetischen Parameter gefunden wurden, belegt eine hohe statistische Zuverlässigkeit. Das so bestimmte kinetische Modell erlaubt es, den Prozeß zu simulieren und zu optimieren, mit dem Ziel, die endgültige Qualität des Produktes zu verbessern.

[EN] Lipid damage during albacore processing was investigated by following fluorescence formation at four different excitation/emission wavelength maxima and brown colour development. Analyses were made on aqueous and organic extracts, as well as in dipping oil samples. A fluorescence shift to higher wavelength maxima was observed as a result of processing. At the same time a marked increase in browning was obtained. The most energic sterilization treatment showed the highest damage and fluorescence shift to higher wavelength maxima., [DE] Lipidschäden während der Verarbeitung von Albacore (Thunnus alalunga) wurden durch die Entwicklung von Fluorescenz (Maximum vier verschiedener Wellenlängen) und Bräunung untersucht. Analysen wurden mit wäßrigen und organischen Extrakten sowie Ölmustern durchgeführt. Als Ergebnis des thermischen Prozesses wurde eine Fluorescenzverschiebung zu höheren Wellenlängenmaxima offenbar. Gleichzeitig nahm die Bräunung zu. Daher zeigte die höchste Sterilisationstemperatur die größten Schäden und Fluorescenzverschiebungen zu höheren Wellenlängenmaxima.

[EN] Different species of fresh fish and smoked fish products were analysed by sodium dodecyl sulphate (SDS) polyacrylamide gel electrophoresis and isoelectric focusing. It was possible to differentiate and identify species of fish in smoked samples and draw some conclusions about the type of smoking process employed., [DE] Proben von verschiedenen Arten von Frischfisch und von geräucherten Fischprodukten wurden mit Hilfe von SDS-Polyacrylamid-Gelektrophorese und isoelektrischer Focussierung analysiert. Es war möglich in den geräucherten Proben zwischen verschiedenen Fischarten zu unterscheiden und die Fischart zu bestimmen. Ebenso waren Rückschlüsse auf den angewendeten Räucherungsprozeß möglich.

[EN] Thermal conductivity values of dried and raw albacore muscle were determined by means of a thermal conductivity probe. A microcalorimetric method and differential scanning calorimetry were used to obtain specific heat values of dried and raw muscle and of dried muscle, respectively, at several temperatures between 20 °C and 150 °C. Thermal diffusivity was calculated during precooking of headed and eviscerated albacore and during heat treatment of cylindrical cans filled with edible parts of precooked albacore. The experimental temperature curves were adjusted to those obtained from an analytical solution of the heat transmission equation assuming cylindrical geometry, conduction mechanism and constant thermal properties of the material. From experimental thermal conductivity, specific heat and density values, thermal diffusivity values of 1.43 x 10−7 m2/s with perpendicular heat flux to fibers and 1.65 x 10−7 m2/s with parallel heat flux were calculated for raw albacore. The values of apparent thermal diffusivity were found 1.51 x 10−7 m2/s and 1.29 x 10−7 m2/s during precooking and heat treatment of cans, respectively., [DE] Die Wärmeleifähigkeit von getrocknetem und frischem Thunfisch wurde durch eingehende Untersuchungen bestimmt. Hierfür wurde eine mikorcalorimetrische Methode sowie die Differentialabtast-Calorimetrie angewandt, um damit die Werte für die spezifische Wärme des getrockneten und des frischen Muskels bei Temperaturen zwischen 20 °C und 150 °C zu bestimmen. Die Wärmediffusion wurde während des Vorkochens des ausgeweideten Thunfisches (aber mit Kopt) und während der Erhitzung der in Dosen abgefüllten eßbaren Teile des vorgekochten Thunfisches berechnet. Die experimentell erhaltenen Temperaturkurven wurden mit dene aus der analytischen Lösung der Wärmeübertragungsgleichung erhaltenen (bei Annahme einer cylindrischen Geometrie), des Leitfähigkeitsmechanismus und den konstanten thermischen Eigenschaften des Materials abgestimmt. Aus den experimentell gefundenen Werten wurde eine Wärmediffusion von 1,65·10−7 m2/s bei parallelem Wärmefluß für rohen Thunfisch gemessen, während beim Vorkochen bzw. bei Erhitzung von Dosen diese Werte bei 1,51·10−7 m2/s bzw. 1,29·10−7 m2/s lagen.

[EN] The effects of cooking and sterilization at several temperatures on the free amino acids (FAA) content in albacore (Thunnus alalunga) muscle were studied during the processing of canned tuna. FAAs were derivatized witho-phtalaldehyde, separated on a C18 column by HPLC and detected by both fluorescence and ultra-violet detectors. After cooking the loss of FAAs was not significant. However, in the final product sterilized at 115 °C and 110 °C (throughout the whole process) there were significant losses with regard to the start material, but not at 118 °C (all temperatures leading to the same lethal F-value). The influence of the thermal process time at 115 °C was evaluated for 60 and 100 min. Significant losses were found between both canned products (≈25%) and between the raw fish and the final product (≈12% and ≈34%, process time 60 and 100 min, respectively). The determination of the content of FAA present in canned albacore may be a useful indication of the severity of the thermal processing., [DE] Die Wirkung des Kochens und Sterilisierens bei verschiedenen Temperaturen auf den Gehalt an freien Aminosäuren (FAA) im Thunfischmuskel (Thunnus alalunga) wurde während der Herstellung von Thunfischkonserven untersucht. Die freien Aminosäuren wurden mito-Phtalaldehyd derivatisiert, auf einer C-18-Kolonne mit HPLC abgetrennt und durch Fluorescenz und UV-Detektoren nachgewiesen. Nach dem Kochen war der Verlust an FAA nicht signifikant, jedoch in dem bei 110° und 115 °C sterilisierten Endprodukt ergaben sich signifikante Verluste bezogen auf das Ausgangsmaterial, aber nicht auf das bei 118 °C erhitzte; alle Erhitzungstemperaturen führen zu demselben letalen F-Wert. Der Zeiteinfluß der Erhitzung bei 115 °C wurde bei 60 und 100 min bewertet. Signifikante Verluste sind bei beiden Dosenkonserven aufgetreten (≈25%) und zwischen diesen und dem Rohfisch ( ≈12% und ≈34%) bei einer Erhitzungszeit von 60 und 100 min). Die Bestimmung des FAA-Gehalts in Thunfischkonserven kann für den Nachweis der Einwandfreiheit des thermischen Prozesses sehr nützlich sein.