1,430 research outputs found
Direct Electron Microscopy Study on the Morphological Diversity of Bacteriophage Populations in Lake Plußsee
Direct electron microscopy of bacteriophages adsorbed to a carbon film without prior enrichment by specific host strains or concentration by physical or chemical methods was used to study the morphological diversity of natural bacteriophage assemblages in a North German lake. All samples contained a mixture of morphologically different tailed viruses, which were regarded as bacteriophages. Most of them had isometric heads and long noncontractile tails, belonging to morphotype B1 (Siphoviridae). In addition, members of morphotypes A1 (Myoviridae), B2 (Siphoviridae with elongated heads), and C1 (Podoviridae) were present in lower numbers. Only one cubic virus was detected, while no filamentous or pleomorphic phages were found. Up to 11 different phages per sample, and a total of 39 phages when all samples were considered together, could be distinguished by morphological criteria. The total number of phages was estimated to be on the order of 108/ml
Farbstoffgehalte in Lachsersatzprodukten aus Seelachs und Alaska-Seelachs und Veränderungen bei Lagerung im Kühlschrank
Heavy salted and brightly red coloured slices and cuttings of saithe and Alaska pollock (in German called: Lachsersatz) have a long tradition on the German market and a high consumer acceptability. The food colours E 110 and E 124 are used to produce the typical red colour of these products. An allowable limit of 500 mg/kg has been set for the sum of both colours but data on the actual concentrations are missing. In this study the results of colour measurements of various market samples are presented. Furthermore a study was undertaken to determine possiblechanges in colour concentrations during storage of typical products thereof in an house hold refrigerator
Einfluss der Verarbeitung auf lipophile chlororganische Rückstände in Fischen
Influence of fish processing methods on changes of
chlordane and toxaphene residue concentrations were
studied in various fishery products. Investigation included
smoking, marinating and canning of fish. Smoking
of Greenland halibut and ocean perch led to an increase
in chlordane and toxaphene residue amounts in
the edible part in relation to the raw material. A similar
increase was observed during the marinating process
of herring fillets. In both cases, loss of water was responsible
for the observed changes in residue contents.
The fat and thus the lipophilic organochlorine compounds
remained completely in the products. Canning
of herring fillets in tomato sauce reduced the residue
concentration of the final product due to dilution by
the tomato sauce. The concentrations in the fillets kept
nearly unchanged even after storage of cans for six
months. No equilibration was observed between residue
concentrations in fillets and sauce
Untersuchungen zur chemischen Zusammensetzung und Nematodenbelastung von Stinten (Osmerus eperlanus L.)
Smelt (Osmerus eperlanus L.) from the river Elbe has a long tradition as local food speciality. It is offered baked or fried every year during spring in many restaurants along the river. Information about the composition of the edible part and its changes during fishing season are scarce. In earlier days the fish was mostly sold by local fisherman directly after catch. Today the fish is also offered as ungutted fresh fish in ice on the whole sale market. The freshness of this fish has not been studied. Smelt from the river Elbe is known to contain nematode larvae (Pseudoterranova decipiens) in the muscle meat. Actual quantitative data on the abundance and prevalence in the commercially offered ice stored fish are missing
Lipophile organische Rückstände im Nahrungsmittel Fisch. Eine aktuelle Bestandsaufnahme
Lipophilic organic substances in the environment are nearly exclusive of anthropogenic origin. Input of contaminants to sea and fresh water lakes arise via rivers, the atmosphere, direct intake and disposals. Intake by fish occurs via diet or directly from the water. The contamination level in fish is influenced by the fishing ground, fat content, biological cycle and age of the fish. But the effect for fish as food is very limited. Levels of lipophilic organic contaminants in the edible part of fish important for human consumption are far below the German maximum allowable evels of residues and pollutants
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