Ziele und Methoden der elektrochemischen Verfahrens- und Reaktionstechnik

Objectives and methods of electrochemical process and reaction engineering . Electrolysis processes are distinguished from ?normal”? chemical processes in several respects: (1) The electrical energy consumed is expensive and assumed the role of an expensive raw material. (2) Mass transfer in electrolytes is sluggish and limits space time yield to relative low values. (3) The rate of reaction is dictated by the applied electrode potential and this determines the cell voltage and energy efficiency of electrolysis processes. Effective electrocatalysts diminish energy consumption per unit mass of product. (4) The relatively poor electrical conductivity of electrolytes leads to construction of special closely spaced cells with narrow cell gaps. It is important to select the operation conditions of, e. g. organo-electrosyntheses to minimise the efforts involved in isolation and purification of the product.     

Composition and quality attributes of conventionally and organically farmed Pangasius fillets (Pangasius hypophthalmus) on the German market

A range of conventionally and organically farmed Pangasius or sutchi catfish fillets available on the German market were analysed to compare both composition and quality. Differentiation of Pangasius hypophthalmus from Pangasius bocourti was achieved by RFLP-SSCP analysis. The protein content of conventionally farmed fillets ranged between 13.3 and 15.7%, whereas organically produced fillets had significantly higher protein contents of between 17.0 and 17.4%. No difference in the fat content between farming methods was observed, which varied between 1.4 and 3.2%. Polyunsaturated fatty acids represented about 24% of the total fatty acids with a high level of linoleic acid. The comparison of the proximate composition indicated that water was added to most of the conventionally farmed products, in different amounts, as well as water-binding capacity enhancing additives. Differential scanning calorimetry was used to demonstrate the presence of polyphosphate on muscle proteins. Differences in texture, water-binding capacity and colour are discussed.     

Electrophoretic techniques for species identification of fishery products

Summary At the present time species identification of fishery products is mainly performed by electrophoresis; in most cases isoelectric focusing (IEF) is given preference over other electrophoretic techniques. In this review the possibilities of application of IEF and other electrophoretic methods for analysis of raw, dried, salted, smoked, ripened, cooked or canned fish are discussed. It is shown that the protein patterns may be influenced by the type of muscle (light or dark), the freshness of fish or fillet, and by the conditions of frozen storage. Reference samples must often be used to obtain unequivocal results. A protein dry powder is introduced, which has been prepared from the sarcoplasmic fraction of many fish species yielding species-specific protein patterns. The powder is stable at room temperature and can be shipped without cooling.

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Elektrophoretische Methoden zur Bestimmung der Tierart in Fischereiprodukten

Zusammenfassung Zur Zeit erfolgt die Bestimmung der Tierart in Fischereiprodukten nahezu ausschließlich mit elektrophoretischen Methoden, vorzugsweise durch die isoelektrische Focussierung (IEF). In der vorliegenden Übersichtsarbeit werden die Anwendungsmöglichkeiten der IEF und anderer Elektrophoreseverfahren zur Analyse roher, getrockneter, gesalzener, geräucherter, gereifter, gegarter oder sterilisierter Fischereiprodukte diskutiert. Es wird aufgezeigt, in welchem Ausmaß die Proteinmuster durch die Art der Muskulatur (hell oder dunkel), den Frischegrad der Fische bzw. Filets und durch die Gefrierlagerbedingungen der Produkte beeinflußt werden. In vielen Fällen kann auf Referenzproben nicht verzichtet werden; es wird ein Proteinpräparat vorgestellt, das aus der sarkoplasmatischen Fraktion zahlreicher Fischarten isoliert wurde und Spezies-spezifische Proteinmuster lieferte. Das Präparat ist bei Raumtemperatur stabil und kann daher ohne Aufwand verschickt werden.

     

Synthesis and X-ray crystal structure of a bis-cyclometalated phosphorescent red-emitting iridium(III) complex

The synthesis of the bis-cyclometalated complex [{Ir(μ-Cl)(ccpz)₂}₂] (1, cppz = 1-chloro-4-(4-chlorophenyl)-phthalazine) from hydrated iridium(III) chloride and the ligand ccpz in refluxing ethoxyethanol is described. Compound 1 was characterized by spectroscopic means and the crystal structure was determined by X-ray crystallography. The absorption and emission spectra exhibit the new compound as a red-emitting phosphorescent complex.     

Die nutzung gentechnischer methoden zur produktion wertvoller proteine in mikroorganismen

The genetic make-up of living systems especially of isolated cells can be altered by a variety of methods including chemical or light-induced mutation. More modern procedures are the in vitro recombination of nucleic acids and the cell-cell fusion. The new methods are especially useful to reprogram microorganisms to produce valuable proteins or other natural products in excess quantties. In the following we will elucidate the importance of the new techniques by describing the bacterial production of glucose dehydrogenase, of the proteinase inhibitor stefin A and by outlining the methods and promisses of substractive cloning. Although the economic value of genetic engineering techniques still awaits justification, the importance of the methodology for basic biological research is well documented.     

Diamondoid Phosphines – Selective Phosphorylation of Nanodiamonds[1]

The diamondoids (nanodiamonds) diamantane and triamantane were selectively converted into diorganophosphinic acid chlorides by reacting them with phosphorus trichloride under Friedel–Crafts‐like conditions. The di‐diamondoid phosphinic acid chlorides were subsequently reduced with trichlorosilane to give the hitherto unknown corresponding di‐diamondoid phosphines. These diamondoid phosphinic acid chlorides and phosphines are of great utility as starting materials in organo‐element and coordination chemistry due to their extraordinary rigidity and steric bulk.