9 resultados para Niebuhr, Carsten, 1733-1815.
em Aquatic Commons
Resumo:
Hypoptopoma inexspectata is diagnosed and redescribed based on the examination of additional material and comparison with its congeners. This poorly known hypoptopomine species is distributed in the Paraguay and Paraná river draínages. Hypoptopoma inexspectata is diagnosable based on the autapomorphy biserial arrangement of anterior snout rostral margin odontodes, laterally extended to limit between second and third infraorbital plates, with dorsally directed dorsad series separated from ventrally directed ventrad series by a narrow odontode-free area, which at the level of first and second infraorbital plates is reduced to a dividing line of the series. The species can be further distinguished by the combination (1) low number of canal-bearing lateral plates (20-22, typically 21), (2) presence of a shield of prepectoral dermal plates, (3) arrangement of abdominal plates in one paired series of 3-5 plates, (4) shorter least interorbital distance 4856% head lengh, (5) larger horizontal eye diameter 17-20% head lengh, and (6) least orbit-nare distance 812% head lengh. Intraspecific variation skull dermal bones, neuracranium and suspensorium bones, dermal plates, adipose fin is reported. (PDF has 20 pages.)
Resumo:
Mediterranean fish species and fish species from other southern countries are retailed increasingly on the German market. The fish is stored in ice eviscerated or as whole fish and imported by truck or by airplane. In the present investigation, the freshness, the sensory quality and the microbiological status was determined of gilthead sea breams (Sparus aurata) from farms in Italy and France and from sea breams (Sparus ehrenbergi) of wild captures from Senegal. It is shown, that farmed gilthead sea breams were of high sensory quality and in good microbiological conditions.
Resumo:
New regulations of the German “Fisch-Hygiene-Verordnung” lay down that all fish except pelagic species have to be gutted immediately after catch or killing, especially fresh water fish from aquaculture. Only gutted fish should be sold to the consumer. At the present time, however, it is not unusual to sell ungutted fish like tropical or mediterranean species from foreign countries, even the EC area. In this investigation the influence of gutting on the fish quality during storage on ice was tested in tench (Tinca tinca) as a model. Quality changes were controlled by sensory, chemical, physical and microbiological assessment. It was shown that for tench there were no differences between gutted and ungutted fish during 12 days of storage on ice.
Resumo:
After the evaluation of 48 samples consisting of hand and machine-peeled sand shrimps it can be stated that there was no significant difference in quality between both. The quality of the sand shrimps was evaluated by sensorially performed paired comparison as well as by estimating the microbial load and the volatile amines (MMA, DMA, TMA). Additionally, the colour characteristics were measured instrumentally. To characterise the influence of the technological regime measurements of pH and of the salt content were performed. The quality of sand shrimp is further influenced by technological steps as freezing, cooking procedure and preservatives used. From the hygienic point of view the machine-peeling was without any objections. The microbial load was small and below the limit set by EC. Measurement of volatile amines was not suited to make visible difference created be the various peeling methods.
Resumo:
The investigations showed that the shelf life of traditional smoked and vacuum-packed gutted mackerels, mackerel and herring fillets is similar to the corresponding vacuum-packed products smoked with liquid smoke. The storage temperature was 5 ± 0,5 °C. Under experimental conditions the storage time was 26 days for smoked gutted mackerels and more than 30 days for smoked fillets. Storage times of 20 to 25 days for these products are recommended. The microbiological and chemical results showed no differences between both technologies.
Resumo:
During the 160th research cruise of the FRV "Walther Herwig III" in the North Sea in May 1995 an ice-storage experiment with whiting was performed. Gutted whiting with and without spleen was stored in melting water-ice. Freshness and/or spoilage were monitored by measuring sensory, chemical, physical and microbiological indicators. It was found that besides the classical sensory assessment on the cooked sample and the EU-quality grading scheme, the microbiological counts were of major importance for the determination of the degree of freshness or spoilage. The cfu (colony forming units) of spoilage bacteria on the skin correlated significantly with time in ice. A very good correlation was also found for the cfu of spoilage bacteria with the sensory assessed odour of the cooked fillet sample. The measurement of the fish tissue with the Intellectron Fischtester VI and the determination of the creatine content in fillet are both suitable freshness and spoilage indicators. The pH-value measured in different body compartments and in musele homogenate and the ammonia content are only of limited value for freshness determination. Removal of kidney did not influence the shelf life.
Resumo:
We compared the capture efficiency and catch dynamics of collapsible square and conical pots used in resource assessment and harvesting of red king crabs (Paralithodes camtschaticus [Tilesius, 1815]) in the Barents Sea. After two days of soaking, square pots caught three times as many crabs as conical pots, and their catches consisted of a higher proportion of male crabs and male crabs larger than 160 mm carapace length compared to the catches in the conical pots. Catches in the square pots did not increase as soak times were increased beyond two days, which indicates equilibrium between the rate of entries into and the rate of exits from the pots. Catches in conical pots, however, increased with increasing soak times up to eight days, the longest soak time examined in this study. These findings demonstrate the higher efficiency of square pots and the importance of understanding catch dynamics when making population assessments based on catchper-unit-of-effort data. The favorable catch characteristics and handling properties of the collapsible square pot may make this pot design suitable for other crab fisheries, as well.
Resumo:
Kurzfassung Die Lebensmittelbranche erwartet durch den Einsatz von Nanotechnologien hervorragende Fortschritte bei der Verbesserung der Produktqualität und der Lebensmittelsicherheit. Vor diesem Hintergrund wurde 2009 am Max Rubner Institut der Fach- und Institutsübergreifende Forschungsschwerpunkt „Nanotechnologie“ etabliert, um Grundlagen zu erarbeiten, aufgrund derer die Auswirkungen der Nanotechnologie auf Lebensmittel und damit die Ernährung und Gesundheit der Verbraucher beurteilt werden können. In diesem Forschungsprojekt wurde der Einfluss neuer, mit Nanopartikeln beaufschlagter Verpackungsfolien auf Fischfilet untersucht. Abstract: The food industry expects by the application of nanotechnology excellent progress in the improvement of the product quality and the food safety. On this background the Max Rubner Institute established in 2009 an interdisciplinary focus on nanotecchnology research to formulate principles upon which the impact of nanotechnology on food and thus the nutrition and health of consumers can be assessed. In this research, the impact of new, nanoparticles containing packaging films was examined for fish fillet.