Mario Giaccio

Characterisation of the Regional Origin of Sheep and Cow cheeses by Casein Stable Isotope (13C/12C and 15N/14N)

The stable isotope ratios ( 13 C/ 12 C, 15 N/ 14 N) of casein from cheeses measured by isotope ratio mass spectrometry (IRMS) in samples of sheep and cow cheeses from Abruzzo, Friuli, Lazio and Sardinia, were found to be accurate parameters of place of origin, independently of seasoning time. Multivariate data treatments, by applying supervised (Linear Discriminant Analysis) method, revealed good discrimination possibilities for determining the place of origin of the cheese, with a percentage of correctly assigned cases equal to 100%.

Level of «cis-» and «trans-» resveratrol and their glucosides as a function of different cultivar of red wines

Variability of trans - and cis -resveratrol and their glucosides in red wines, coming from 13 different species of vine grown on two parallel plots of land, different for pedo-climatic conditions, during three different vintages, was determined by HPLC. The data obtained were elaborated by multivariate statistical analyses (Principal Component Analysis and Discriminant Analysis). The results showed that trans - and cis -resveratrol are more correlated than transand cis -glucoside, due to the uniformity of vinification treatments. Furthermore, Principal Component Analysis pointed out a good separation among five types of wine (Pinot noir, Malbeck, Gaglioppo, Refosco and Ciliegiolo), coming from the same cultivars, which are also discriminated in the Discriminant Analysis as a function of resveratrol content. This would underline that the cultivar variable, almost for the five above mentioned cultivars, has a higher influence than the other factors in wine characterisation with respect to their content of resveratrol.

Glucidic Patterns of Neutral Non Starch Polysaccharides in Wheat Dietary Fiber Products by HRGC and HPLC

Dietary fiber [DF] has received considerable attention because of its possible beneficial effects for human health; thus, several methods have been attempted for analysis and characterization of DF. In this paper the valuation of the fiber composition on some cereal products is reported. The fiber determination has been carried out by means of three procedures, different for derivatization conditions and chromatographic separation techniques; the first two, yet described in previous papers, are based on derivatization of monoses to alditol acetates or nitrile-peracetates and on GLC or HRGC separation respectively. The third procedure regards a new attempt, based on derivarization of alditols [obtained from monoses] by phenylisocianate to corresponding urethanes and on their separation by gradient RP-HPLC. The results show that the RP-HPLC procedure can be considered a valid alternative to GC techniques.

Content of Resveratrols as a Function of Red Wine Cultivar and of the Year Production (2000-2001-2002)

As a continuation of a previous research project, the variability of trans - and cis -resveratrol and their glucosides in red wines, from 14 different species of vine, was determined. The wine came from grapes grown on two plots of land at two separate locations differing in pedo-climatic conditions. The content of total resveratrol is between 1.55 and 16.76 mg/L with an average value of 6.71 mg/L. Moreover the results showed that trans - and cis -resveratrol are more correlated (r = 0.83) than trans - and cis -glucoside (r = 0.72), due to the uniformity of vinification treatments. The species of vine, having a higher mean content of total resveratrol, are: Refosco, Pinot Nero, Ciliegiolo, Montepulciano e Gaglioppo. The data, elaborated by multivariate statistical analyses (Principal Component Analysis and Discriminant Analysis), pointed out a good separation between the three vintages as a function of resveratrol content.

Stereospecific Analysis of the Main and Iso-Unsaturated Triacylglycerol Fractions to Differentiate Triticum durum from Triticum vulgare

The main isoinsaturated triacylglycerol sub-fractions were analysed in flour from Triticun durum, T vulgare and their mixtures in order to differentiate, using the data of their stereospecific analysis, the two species and their mixtures. The results showed that the stereospecific analysis of the main sub-fractions is able to discriminate both the two kinds of wheat and to recognize the presence of small quantities of T. vulgare in T. durum one.

Sex Discrimination of Fishes by Trace Element Content Using a Multivariate Statistical Approach

To discriminate the sex of fish species belonging to the same aquatic environment, 10 trace elements were determined. The data collected were successively elaborated using two multivariate statistical techniques: linear principal component analysis and linear discriminant analysis. LPCA did not allow us a good differentiation of fish samples, whereas LDA best discriminated all samples under study both for species and for sex. From a statistical analysis it has also been possible to observe that there were more important variables from an environmental pollution point of view which were inversely correlated to condition index, closely connected to the fishes’ physical conditions.