Pietro Renon

Ostrich meat: Physico-chemical characteristics and comparison with turkey and bovine meat.

In several European countries ostrich breeding has now become quite common. In Italy this has also given rise to the need for regulations for the slaughtering of Ratites. The present work studies and compares the physico-chemical characteristics of the meat from the thigh of the ostrich with the same anatomical cuts of turkey and bovine. The ostrich meat muscle of the thigh was imported vacuum packed from Israel and France, the muscles considered were m. flexor cruris and m. iliofibularis. The turkey thighs were from the domestic market (supermarket) and the bovine muscle m. pectineus was from spent milking animals from an EEC slaughterhouse. Needless to say that the breeding, the feeding and the system of slaughtering could influence some parameters of the different kinds of meat; however these factors could not be assessed. Due to its tenderness, low fat content and cholesterol levels ostrich meat is, in accordance with modern-day nutritional principles, a valid alternative to other kinds of meat.

Computer-assisted evaluation of isoelectric focusing patterns in electrophoretic gels: identification of smoothhounds (Mustelus mustelus, Mustelus asterias) and comparison with lower value shark species.

In this work, the most commercially important Selachian species, smoothhound (Mustelus mustelus) and starry smoothhound (Mustelus asterias), have been identified by polyacrylamide isoelectric focusing (IEF‐PAGE), along with several shark species of minor commercial value. In Italy, these two smoothhound species are commonly subjected to fraudulent substitution with lesser valued sharks. After the electrophoretic runs, the band patterns of the two Mustelus species were compared with those of dogfish (Scyliorhinus canicula), spurdog (Squalus acanthias), blue shark (Prionace glauca) and black‐mouthed dogfish (Galeus melanostomus), both visually and with gel analysis software. The actual isoelectric points were then submitted to cluster analysis to differentiate the single species, despite the possible occurrence of electrophoretic variations or protein polymorphism. Every shark showed species‐specific band patterns and could therefore be well differentiated, as confirmed by statistical analysis.

Substitution of fish species detected by thin-layer isoelectric focusing and a computer-assisted method for the evaluation of gels.

Fourteen fish species susceptible to substitution were analysed by the thin-layer isoelectric focusing technique on polyacrylamide gels of pH 3.5-9.5. Four fish per species were run on the same gel to verify the possibility to differentiate them according to their protein banding patterns. The occurrence of intraspecific differences due either to electrophoretic variations or to protein polymorphism was also observed. In fact, some of them showed few dissimilarities among their protein profiles. However, the differentiation was possible for all species, even for those belonging to the same order, family and genus. Computer-based tools combined with statistical analysis were implemented and usefully applied to avoid a subjective evaluation of the isoelectric focusing gels, and to verify the reliability of the preliminary visual comparison of protein patterns.

New, stable halogenated derivative suitable for the gas Chromatographic determination of muramic acid

The 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-N,N-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.

Gas chromatographic determination of galactose in milk: Example of a switching valve used for the protection of the capillary column

Galactose, 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 prederivatization 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.