Search

To provide a comprehensive overview of the amounts of unesterified and bound 2- and 3-monochloropropanediol (MCPD) and glycidyl esters (G–E) in processed fishery products sold in Germany, an analysis of various frequently consumed products was conducted. In total, 258 commercial samples of breaded and pre-fried fishery products (e.g., frozen fish fingers), fried fish products (e.g., products in marinade), canned fish, smoked fish and some smoked spice preparations were examined. In addition, the effect of different kitchen preparation methods (e.g., baking, frying and roasting) on the MCPD and G–E amounts of fish fingers was studied. The mentioned process contaminants, MCPD and G-E, were quantifiable in the majority of the samples. Although pre-fried and fried fishery products predominantly contained MCPD esters (MCPD-E), mainly free MCPD was found in smoked fish. Compared with other types of smoke generation, hot smoked fish prepared in traditional Altona smoking kilns contained, on average, the highest 3-MCPD contents (range: 12–246 µg/kg). The amounts of bound MCPD in the fried fish products (range for 3-MCPD-E

Notas: Documento pegado a una hoja en blanco. Datos de la publicación manuscritos encima del artículo. Sello "Für den Autor" ("Para el Autor") en la parte lateral inferior izquierda., Tipo de publicación: Periódico, Título de la publicación: Frankfurter Allgemeine Zeitung, Periodicidad: Diario

Notas: Un folio con los datos manuscritos acompaña el documento en la cual está el sello "Für den Autor" ("Para el Autor") en la parte inferior izquierda., Tipo de publicación: Revista, Título de la publicación: Neue Deutsche Hefte, Número de la publicación: 100, Periodicidad: Mensual

Anisakid nematode larvae (NL) in fish products comprise a risk to human health and, if visible, lead to the rejection of these products by consumers. Therefore, great efforts are being made for the identification of these anisakid larvae to estimate the potential consumer health risk as well as to develop effective detection methods in order to prevent the introduction of heavily infected fish products into the market. The tasks of national reference laboratories include the improvement of detection methods and to promote their further development. As a prerequisite for improved detection, it is important to understand the structural properties of anisakid NL and compounds produced during host-parasite interactions. This review provides an overview of the intrinsic properties of anisakid NL and reports the latest detection methods in published literature. First, in order to define the potentially interesting intrinsic properties of anisakid nematodes for their detection, anatomy and compounds involved in host-parasite interactions are summarised. These can be used for various detection approaches, such as in the medical field or for allergen detection in fish products. In addition, fluorescence characteristics and their use as both established and promising candidates for detection methods, especially in the field of optical sensing technologies, are presented. Finally, different detection and identification methods applied by the fish processing industries and by control laboratories are listed. The review intends to highlight trends and provide suggestions for the development of improved detection and identification methods of anisakid NL in fish products.

Canned liver is a highly valuable and healthy product from the important commercial fish species cod Gadus morhua. Due to high levels of contaminants such as dioxins and dioxin-like PCBs (polychlorinated biphenyls) in cod liver products from the Baltic Sea, the grounds for supply of cod liver were relocated to areas around Iceland in the Irminger Sea with lower levels of contaminants. In the present study, 62 canned samples, as well as 132 fresh cod livers from Greenland and Iceland, were analysed in order to assess the infection levels with anisakid nematode species. High prevalence and abundance of the potentially zoonotic nematode species Anisakis simplex s.s. and Pseudoterranova decipiens s.s. were found in the fresh livers. Lower infection levels in canned livers compared to fresh livers might indicate successful industrial processing measures in order to reduce nematode larvae in the final products. However, two heat stable allergens, Ani s 1 and Ani s 4, were verified from isolated nematode larvae from canned products. The effectiveness of methods to further reduce the number of nematode larvae during industrial processing of cans with cod liver is discussed.

Beaked redfish (Sebastes mentella) and Greenland halibut (Reinhardtius hippoglossoides) were collected from fishing grounds of the Barents Sea to study the composition and lipid distribution of the muscle tissue. The belly flaps of beaked redfish showed higher lipid contents (mean 4.6%) compared to anterior dorsal muscle. The protein content was relatively constant in all parts (18–19%). The variation in the muscle lipid composition among individual redfish was greater than the variation among different anatomical locations of the fillets. No significant differences were found in the composition of Greenland halibut muscle parts. The protein content was generally low and ranged between 12.2–13.9%. The lipid content varied considerably between approximately 6 and 17%, displaying large variations of the lipid contents between different Greenland halibut individuals from one catch. The variability of lipid content should be considered in the risk assessment and management of lipophilic contaminants in fish fillets. A correlation between water and lipid content was found for both species (r = −0.8750, beaked redfish; r = −0.8732, Greenland halibut).

Pre-frying of chloride-containing raw materials (e.g., breaded frozen fish products) can lead to the formation of fatty acid esters of 2-monochloropropane-1,3-diol, 3-monochloropropane-1,2-diol (MCPD-E), and glycidol (G-E). The aim of the present study was to identify relevant parameters for the formation of these process contaminants during the pre-frying. Secondly, several mitigation approaches have been investigated. The major proportion of the MCPD-E and G-E in the fish products resulted from the pre-frying oil absorbed, while the temperature and the heating period of the pre-frying oil showed the strongest impact. A significant reduction of the MCPD-E content in the pre-frying oil was achieved by filtering-off solid breading particles. Additionally, the G-E content decreased resulting from the use of adsorbent materials. Moreover, the analyses of total polar material and the color intensity of the pre-frying oil are suggested as screening methods for estimating the MCPD-E and G-E contents in the fish products.

Nile perch ( Lates niloticus ) is a popular, usually low priced food fish in many countries worldwide, and the most important export fish from Lake Victoria and its adjacent countries Uganda, Tanzania and Kenya. Despite its high import figures, the constantly increasing demand within the EU for ‘new’ fish species and the results of initial studies indicating high coliform bacterial loads, food safety aspects regarding its microbiological as well as parasitological status have been hitherto widely neglected. In the present study imported fresh fish fillets as well as superchilled fish from a German retail market and a Dutch wholesaler were examined to evaluate the current microbiological and parasitological quality. A total of 200 fresh fillets as well as 20 superchilled fish (beheaded, eviscerated, descaled) samples were screened for the presence of helminth parasites by visual inspection, candling, the UV-press method and artificial digestion method. The study includes as well a quantitative test on the recovery rate of metacercarial cysts. Microbial assessment was performed on ten fresh fillets and on the skin and tissue of 20 superchilled fish. Helminth parasites were neither detected in the edible parts nor in the skin of imported products. Results of the microbiological examination revealed low levels of bacterial contamination of superchilled fish samples, whereas high total viable counts and high levels of naturally present bacterial pathogens of the genus Aeromonas spp. and Pseudomonas spp. were identified from the fresh fillets. Our findings indicate that hygienic production conditions have improved in comparison to previous studies. As total viable counts as well as specific spoiling bacteria were high in fresh fillets, we recommend adequate heat treatment of fresh Nile perch fillets before consumption.

Fish and fish oil are an important source of essential dietary components such as polyunsaturated long chain fatty acids like eicosapentaenoic acid and docosahexaenoic acid. Refining of crude fish oil is necessary to remove environmental contaminants e.g., dibenzo- p -dioxins, dibenzofurans, dioxin-like polychlorinated biphenyls, and non-dioxin-like polychlorinated biphenyls for reaching legal limits, ensuring a pleasant taste and for enhancing shelf-life. However, during the deodorization of crude fish oil, process contaminants such as 2- and 3-monochloropropane-diol esters and glycidyl esters may be formed. The aim of the present study was to provide a comprehensive overview on the content of selected environmental and process contaminants in raw and processed fish oils deriving from different fish species. In crude fish oils extracted from farmed fish, the contents of environmental contaminants were well below the legal limits for food grade fish oil. In contrast, fish oils extracted from captured fish did not meet the requirements for human consumption. When applying filtration over active carbon, a reduction in the content of dibenzo-p-dioxins, dibenzofurans and dioxin-like polychlorinated biphenyls was achieved. 2- and 3-monochloropropane-diol ester and glycidyl ester contents were considerably higher in the refined compared to the crude fish oils investigated. Additionally, the comparison of analyzed and labeled contents of polyunsaturated long chain fatty acids showed a satisfying compliance.

PurposeTo compare manual corrections of liver masks produced by a fully automatic segmentation method based on convolutional neural networks (CNN) with manual routine segmentations in MR images in terms of inter-observer variability and interaction time.MethodsFor testing, patient's precise reference segmentations that fulfill the quality requirements for liver surgery were manually created. One radiologist and two radiology residents were asked to provide manual routine segmentations. We used our automatic segmentation method Liver-Net to produce liver masks for the test cases and asked a radiologist assistant and one further resident to correct the automatic results. All observers were asked to measure their interaction time. Both manual routine and corrected segmentations were compared with the reference annotations.ResultsThe manual routine segmentations achieved a mean Dice index of 0.95 and a mean relative error (RVE) of 4.7%. The quality of liver masks produced by the Liver-Net was on average 0.95 Dice and 4.5% RVE. Liver masks resulting from manual corrections of automatically generated segmentations compared to routine results led to a significantly lower inter-observer variability (mean per case absolute RVE difference across observers 0.69%) when compared to manual routine ones (2.75%). The mean interaction time was 2 min for manual corrections and 10 min for manual routine segmentations.ConclusionsThe quality of automatic liver segmentations is on par with those from manual routines. Using automatic liver masks in the clinical workflow could lead to a reduction of segmentation time and a more consistent liver volume estimation across different observers.

Regarding cod as sea food for human consumption and as bio indicator of the marine eco system, this study is the first approach to combine the analysis of organic and inorganic contaminants and radionuclides in cod muscle as well as PCDD/Fs and dl-PCBs in its livers from the same fishing areas. Concentrations of 1-hydroxypyrene, PCDD/Fs, PCBs, cesium-137 (Cs-137), cadmium and lead were determined in individual or pooled samples over a wide geographic area, including Greenland Seas, Barents Sea, North and Baltic Sea. Highest concentrations were found in samples from the Baltic Sea, lowest in the pristine areas of the Barents Sea and Greenland. Levels of contaminants in cod muscle were found to be far below the established EU maximum levels (ML), regardless of which fishing grounds. In contrast to this, most cod liver samples from the North and Baltic Sea showed PCDD/F and PCB contents exceeding the ML. In addition, new background assessment criteria (BAC) for 1-hydroxypyrene in cod of 4.6 ng mL(-1) bile and for Cs-137 a BAC of 0.16 Bq kg(-1) wet weight are proposed to be included in the European Marine Strategy Framework Directive for cod from the Northeast Atlantic.

Beaked redfish (Sebastes mentella) and Greenland halibut (Reinhardtius hippoglossoides) were collected in waters around Svalbard (Barents Sea) to study the influence of different muscle separation/filleting techniques at small and medium fishes on the dioxin/PCB content. Sampling of both species included preparation techniques such as fillets with or without belly flaps, commercially trimmed fillets and cutting into anterior and posterior cutlets. In case of Greenland halibut also the whole edible muscle part and middle cutlets were studied. All samples analysed were far below the maximum level of 6.5 pg/g wet weight (ww) WHO-PCDD/F-PCB-TEQ and 75 ng/g ww ndl-PCB. Trimmed fillets of beaked redfish had the lowest fat content and the lowest level of dioxins and PCB (1.70%, WHO-PCDD/F-PCB-TEQ = 0.320 pg/g ww). The respective posterior cutlets showed the highest fat content and highest levels of dioxins and PCB (2.66%, WHO-PCDD/F-PCB-TEQ = 0.729 pg/g ww). Levels of dioxins and PCB in Greenland halibut samples were generally higher and ranged between WHO-PCDD/F-PCB-TEQ = 0.784 pg/g ww (fillets without bells flaps, fat content = 8.83%) and WHO-PCDD/F-PCB-TEQ = 2.022 pg/g ww (edible part whole muscle, fat content = 8.62%). The results show a considerable influence of the different sampling methods on the dioxin and PCB levels of the species analysed.

18 pages, 10 figures, 6 tables.-- Arne Levsen ... et al., Harvesting and exploiting limited fisheries resources in a sustainable manner also implies achieving maximum added value from the raw material. However, the presence of parasites in the products may adversely affect consumer perception and/or pose a direct health hazard. As a major stepping-stone of the PARASITE project, an epidemiological survey was carried out to provide the basis for analysis and prediction of consumer exposure risk due to the presence of anisakid nematodes in fish from European wild-catch fisheries. The project consisted of nine separate workpackages (WP) where the exposure risk assessment survey was organized within WP2. The surveillance task also provided the data or samples needed for data management and sample storage (WP3, Biobank), molecular and genetic parasite species identification (WP4), and statistical modelling and inference (WP8). In total 17,760 fish belonging to 16 teleost species were examined for anisakids, with special emphasis on economically and ecologically important species such as Atlantic mackerel, herring, European hake, Atlantic cod and anchovy. The target fish species were sampled at four major European fishing areas including the Barents Sea, North Sea, Baltic Sea, Grand Sole Bank, waters off NW Spain and Portugal, central and western parts of the Mediterranean Sea, and the Adriatic Sea. Thus, the survey represents the largest and most comprehensive epidemiological data compilation of anisakids ever generated in terms of geographical range as well as number of fish host species and sample size. An important requirement of the survey was the use of commonly accepted nematode detection methods, i.e. the UV-press method or artificial digestion, to quantify infection level and spatial distribution of anisakid larvae in the target fish species. The basic layout, set-up and principles of the method, along with a discussion of possible source of errors are described. Additionally, the molecular and genetic markers which were used to identify and characterize different species and populations of anisakids from the targeted fish host species and geographical areas, are reviewed as well. Some basic parasite infection characteristics of each fish host species, and any relationships with the presumably most important infection predictors, i.e. fish host body size and fishing locality, are presented and discussed. Emphasis is put on anisakid occurrence in the flesh of the fish. Based on the findings, a graphical exposure risk profile is introduced, including fish species or products thereof, which due to common processing or preparation practices, are at highest risk to act as source of anisakiasis in Europe, The present work was financially supported by the European Union’s 7th Framework Programme for Research, Technological Development and Demonstration, project Parasite risk assessment with integrated tools in EU fish production value chains (PARASITE), Grant Agreement (GA) no. 312068

eingereicht von Horst Pichler Universität Linz, Dissertation, 2018

9 pages, 3 figures, 5 tables.-- Simonetta Mattiucci ... et al., The Atlantic herring is a schooling, pelagic species that inhabits both sides of the North Atlantic Ocean. Herring stock identification is usually based on several approaches, including fish meristic characters, population genetic analysis and the use of parasite species composition. A total of 654 Anisakis spp. larvae collected from herring of four fishing grounds in the Norwegian Sea, Baltic Sea, North Sea, and the English Channel off the French coast, was identified to species level using diagnostic allozymes and sequence analysis of EF1 α−1 nDNA and the mtDNA cox2 genes. Population genetic differentiation of Anisakis simplex (s. s.) among the different fishing areas was estimated, at the intraspecific level, on the basis of mtDNA cox2 sequences analysis. Spatial comparison based on molecular variance analysis and Fst values was performed for the collected specimens (among regions). Haplotype network construction showed relevant differences in haplotype frequencies between samples of A. simplex (s. s.) from the different geographical areas. Results indicate a genetic sub-structuring of A. simplex (s. s.) obtained from herring in different areas, with the population from the Norwegian Sea being the most differentiated one, and with North Sea and Baltic Sea populations being most similar. The population genetic structure of A. simplex (s. s.) was in accordance with the herring population genetic structure throughout the host’s geographical range in the NE Atlantic. Results suggest that mtDNA cox2 is a suitable genetic marker for A. simplex (s. s.) population genetic structure analysis and a valuable tool to elucidate the herring stock structure in the NE Atlantic Ocean, The research was carried out with funding received from the European Union’s Seventh Framework Programme for research, technological development and demonstration, under the grant agreement no. 312068 “PARASITE”

Automatic liver tumor segmentation would have a big impact on liver therapy planning procedures and follow-up assessment, thanks to standardization and incorporation of full volumetric information. In this work, we develop a fully automatic method for liver tumor segmentation in CT images based on a 2D fully convolutional neural network with an object-based postprocessing step. We describe our experiments on the LiTS challenge training data set and evaluate segmentation and detection performance. Our proposed design cascading two models working on voxel- and object-level allowed for a significant reduction of false positive findings by 85% when compared with the raw neural network output. In comparison with the human performance, our approach achieves a similar segmentation quality for detected tumors (mean Dice 0.69 vs. 0.72), but is inferior in the detection performance (recall 63% vs. 92%). Finally, we describe how we participated in the LiTS challenge and achieved state-of-the-art performance.

In the present study, existing official methods for oils were modified in order to analyze free and bound MCPD and bound glycidol in fish. Free 3-MCPD was determined in aqueous extracts of fishery products. DGF standard methods C-VI-17(10) and C-VI-18(10) and the 3 in 1 method were modified and tested to quantify ester-bound 2- and 3-MCPD and glycidyl esters. The different methods were validated using spiked fish mince and a naturally contaminated reference material consisting of homogenized smoked sprat and fish sticks. The methods showed good agreement. Assay B of the modified DGF method C-VI-18(10) and the adapted 3 in 1 method allow a quantitative determination of bound 2- and 3-MCPD in fishery products. In addition, glycidyl esters can be quantified applying the 3 in 1 method. The screening of various fishery products showed that smoked fish may contain considerable amounts of free 3-MCPD. Concentrations ranged between 8 and 388mg/kg wet weight (ww). Only traces of free 3-MCPD were found in all other fishery products. Fish sticks and fried fish products are potential sources of 3- and 2-MCPD esters, but large variation were observed. Bound 3-MCPD ranged between 45 and 377mg/kg ww, bound 2-MCPD between 9 and 116mg/kg ww. Practical applications: The European Food Safety Authority (EFSA) is calling for occurrence data of 2-MCPD, 3-MCPD, 2-MCPD ester, 3-MCPD ester, and glycidyl ester in foods including fishery products. At present, there is no official method for the determination of these food processing contaminants in fish and fishery products. Therefore, the approach of this study was to establish analytical methods for the quantification of free and bound MCPD and bound glycidol in fish, based on the modification of existing methods for edible oils. The adapted methods allow a sensitive quantitative determination of the target analytes in various fishery products.

Parasitic anisakid nematodes commonly occur in the musculature and visceral organs of many fish species from the North Atlantic. In this respect, the presence of the third stage larvae of Anisakis spp. in the fish musculature may pose a potential consumer hazard due to the parasite's ability to cause anisakidosis. Thus, knowledge on the occurrence and distribution of these potentially zoonotic parasites in the commercially important North Atlantic fish species is crucial in order to evaluate and consequently prevent human infections. In the present study, 300 Sebastes mentella from three North Atlantic fishing grounds (Northern North Sea: Tampen; Barents Sea: off Bear Island; Irminger Sea: off SE Greenland) were examined for anisakid nematodes, with emphasis on occurrence and distribution in the musculature. Overall larval prevalence and mean intensity were significantly higher in redfish from Tampen (94%; 13.5±20.0) and Bear Island (94%; 14.5±19.4) than in fish from SE Greenland (75%; 6.0±5.8; p0.01). The same trend was observed for larval infection in the musculature showing prevalence and mean intensities of 79%, 73%, and 55%, and 5.9±6.6, 5.8±6.5, and 3.2±2.4, in the musculature of redfish from Tampen, Bear Island, and Greenland, respectively. Conventional microscopy and rDNA ITS-gene sequencing of various subsamples of muscle-dwelling nematode larvae of redfish from every catching locality revealed the presence of two anisakid species; Anisakis simplex sensu stricto and the non-zoonotic Hysterothylacium aduncum. Since the larvae of H. aduncum typically occur in or on the viscera of fish, our findings of two specimens in the belly flaps of redfish were unusual. Additionally, more than 92% of the muscle-dwelling larvae occurred in the belly flaps, i.e. the hypaxial part of the musculature surrounding the visceral organs on either fish side. Thus, trimming the fillets of beaked redfish by removal of most of the belly flaps would significantly reduce the probability of anisakid nematode larvae to be present in the final product.