Volatile hydrocarbon profile of Iberian dry-cured hams. A possible tool for authentication of hams according to the fattening diet.

The aims of this work were to carry out a comprehensive study of the volatile hydrocarbons of 34 Iberian dry-cured hams and to evaluate the efficiency of these compounds for discriminating hams according to the fattening system: "Montanera" (B) and "Cebo" (C). The samples of hams were obtained by mincing the semimembranosus and semitendinosus muscles from slices of dry-cured ham. The analyses were carried out by gas chromatography-mass spectrometry with a polar capillary column and after a previous extraction by Purge and Trap method. Forty-three volatile hydrocarbons were identified, 26 of them for the first time in Iberian dry-cured ham. Only five compounds showed significant differences between the two types of hams. Among the 33 volatile hydrocarbons, 22 of them allowed a complete discrimination of the two groups of hams according the fattening system.

Authentication of fattening diet of goat kid according to their fatty acid profile from perirenal fat.

Fatty acids of forty-two samples of perirenal fat of goat kids reared on three different feeding systems: goat milk (B), milk replacer (R) and milk-based starter (F) have been analyzed by Gas Chromatography flame ionization detector. The lipids were extracted by melting of perirenal fat in a microwave oven. The fat was then filtered and dissolved in hexane. This analysis was performed on a column (100 m x 0.25 mm i.d. and 0.25 microm film thickness) coated with a polar stationary phase HP-88 and flame ionization detector was used. Hydrogen (25 psi inlet constant pressure) was used as carrier gas. Programmed temperature was kept at 175 degrees C and held isothermally for 10 min, and was then raised to 205 degrees C at a rate of 3 degrees C/min and held isothermally for 10 min. By using the fatty acids as chemical descriptors, pattern recognition techniques were applied to differentiate between goat milk, milk replacer and milk-based starter fattening diet of goat kid. C18:2 and C18:3 acids were found to be the most differentiating variables.