1,720,989 research outputs found
Identification of tuna species by computer-assisted and cluster analysis of PCR-SSCP electrophoretic patterns
No full textFour species of tuna fish (T albacares, T obesus, T alalunga and E. pelamis) were subjected to PCR-SSCP and resulting electrophoretic patterns were analysed with a "computer assisted" method of gel analysis followed by cluster analysis. With this method the species were differentiated at intra-gel level. Inter-gel electrophoretic patterns variability was observed
Determinazione della Malondialdeide in Gas-Cromatografia con rivelazione a cattura di elettroni
No full textMalondialdehyde, a marker of lipid peroxidation . has been analysed by gas-chromatography with electron capture detection as pentafluorobenzyloxime, after a simple derivatzation step carried out at room temperature . The sensitivity appears similar or higher then those previously reported in HPLC and GC-MS determinations. The described method entails the use of an internal standard, which increase the precision of the overall procedure
A new procedura for the specific high-performance liquid chromatographic determination of hydroxyproline
No full textA procedure suitable for a selective high-performance liquid chromatographic (HPLC) analysis of the imino acid hydroxyproline in the presence of a large excess of amino acids is proposed. To deaminate the amino acids, the well-known reaction with nitrous acid is exploited. The N-nitroso derivatives of imino acids obtained are extracted in ethyl acetate, denitrosated by hydrobromic acid, and treated with dansyl-chloride. The final HPLC separations are carried out on a reversed-phase column in a rapid isocratic run. The use of the cis isomer of hydroxyproline as an internal standard allows good reproducibility. As an application of the described method, the hydroxyproline content in samples containing collagen and an excess of bovine serum albumine (up to 20:1) is determined
A case of identification of pectinid scallop (Pecten iacobaeus, Pecten maximus) in a frozen and seasoned food product with PCR technique
No full textSeveral parts of a frozen, cut and seasoned food product, labelled as pectinid scallop (mainly Pecten jacobaeus and Pecten maximus) and suspected to contain vertebrate fish were analysed with PCR: a specific primer pair was designed, tested and used. Moreover an "universal" vertebrate primer pair was applied. The sample was confirmed to be a scallop belonging to P. jacobaeus or P. maximus species
Osservazioni sul pH come fattore di valutazione della vitalità delle principali specie di molluschi bivalvi : Proposta di temperature intermedie
No full textIsoelectric focusing of sarcoplasmic proteins to distinguish swordfish, blue marlin and Mediterranean spearfish
No full textIn the present study we show that the method of isoelectric focusing (IEF) is a simple and reliable one for detecting the fraudulent substitution of cold-smoked fillets of swordfish (Xiphias gladius) with those of lower value blue marlin (Makaira mazara) and for detecting substitution of blue marlin steaks with those of Mediterranean spearfish (Tetrapturus belone). The cold smoking process does not alter the sarcoplasmic proteins of the fish species, so cold smoked fillets of the species investigated can be identified in the same was as fresh and frozen samples
Determinazione di piombo e cadmio in molluschi cefalopodi del Mediterraneo
No full textThe aim of this work was to measure concentration of total Lead and total Cadmium in cephalopods from various areas of the Mediterranean Sea; for each species and areas, three specimens with the same weight were analysed. The two heavy metal were measure by potentiometric stripping unit (PSU20 Trace Lab). All samples had a concentration of the two metals lower than the legal limits. The hightest value of lead was found in flying squid (Todarodes sagittatus) from Sanremo. The hightest value of cadmium was found in flying squid (Todarodes sagittatus) from Bari
Gas chromatographic determination of galactose in milk : example of a switching valve used for the protection of the capillary column
No full textGalactose, a marker of heat treatment, has been analysed in milk as pentafluorobenzyloxime acetate by gas chromatography with flame ionization detection using a simple switching valve system. The procedure did not entail any pre-derivatization clean-up for lactose elimination from the sample. In a short pre-column, reagent and lactose derivative excess were separated and the galactose and internal standard derivatives were transferred to the analytical column by a four-port valve. Thus, the analytical column was protected from overloading, so avoiding rapid deterioration
Filetti di dentici, di letrinidi o di lutjanidi? Identificazione della specie ittica mediante Isoelectric Focusing
No full textNew, stable halogenated derivative suitable for the gas chromatographic determination of muramic acid [short communication]
No full textThe formation of a new volatile derivative of muramic acid is described. The procedure entails a reaction with O-(pentafluorobenzyl)hydroxylamine in pyridine to give the corresponding oxime and a treatment with acetic anhydride in the presence of 4-NJ+‘-dimethylaminopyridine. The structures of the obtained derivatives have been confirmed by MS. The influence of various catalyst amounts used during the acetylation step was studied and a mechanism was proposed in order to explain the different reaction courses
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