Mario Andrea Franco

Comparison of γ-Aminobutyric Acid and Biogenic Amine Content of Different types of Ewe's Milk Cheese Produced in Sardinia, Italy.

The bioactive compounds γ-aminobutyric acid (GABA) and biogenic amines (BA), together with protein-free amino acids, were measured by high-performance liquid chromatography in ewe’s milk cheeses produced in Sardinia with different technological traits. The study included three types of cheese: Pecorino Sardo PDO, Pecorino and Casu Marzu. Farmhouse Casu Marzu and Pecorino showed GABA content (maximum levels: 1001.3 and 378.1 mg 100 g–1 respectively) that had never been found so high in cheese before, suggesting that these types of cheese present ideal conditions to produce GABA. These two types of cheese also showed high levels of BA (their total maximum levels were 1035.7 and 288.0 mg 100 g–1 respectively). Pearson correlation analysis detected significant correlation between GABA and the main BA present in the cheeses (tyramine, cadaverine and putrescine), suggesting that the factors affecting the production of GABA are the same as those influencing BA formation.

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.

Variability of trans and cis resveratrol and their glucosides in red wines produced in Sardinia and Corsica.

Variability of trans - and cis -resveratrol and their glucosides in red wines produced in Sardinia and Corsica was determined by HPLC. The data obtained were elaborated by multivariate statistical analysis (Principal Component Analysis). The results showed a higher average total stilbene content in Corsican samples than in Sardinian samples, due to the aglycons content. Furthermore, PCA pointed out a good separation between the two groups which seems to be related to the samples origin. Lastly, the Cagnulari, which is a particular Sardinian cultivar, showed high values of total stilbenes, related to the glucoside content, as did three Corsican samples.

Effects of Some Yeast on Resveratrol Content During Alcoholic Fermentation

The variability of the content of four monomeric forms of resveratrol (3, 5,4’-trihydroxystilbene): trans and cis -resveratrol, , trans and cis -β-Dglucopyranoside in musts of Cagnulari grapes grown in northwest Sardinia, using different strains of the yeast Saccharomyces cerevisiae , was determined by HPLC at different stages of vinification. The first sample was taken after three days, the second 10 days after inoculation of the yeasts and the third after the samples had been stored for two months at 10°C. The data were elaborated by multivariate statistical analysis, considering the variability of the concentrations of the four stilbene forms at different times. The results showed that from the beginning of sampling the form of resveratrol present in the highest amounts was the glucosylated form, but this had already decreased significantly in the second sample. The decrease in the glucosylated forms was not, however, accompanied by a proportional increase in the free forms. In addition, some yeast strains were identified that do not substantially change the total content of the four monomeric forms of resveratol.

Energy as a determining variable in the production of goods in Sardinia

The evolutionary phase of advanced economic systems is characterised by the progressive substitution of material inputs, including energy, by immaterial inputs. Among these the availability and adaptability of technological innovation, services and the information transfer technology are of particular importance. Innovation processes and technological transformation are among the factors that dominate the evolution of industrial energy consumption. These require programming and continuity in the economic system. The relationship between output and the elements that make up input allow the construction of indices which can accurately describe static and dynamic phenomena of the particular economic system.

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.

Phenolic Acids in Sardinia Vernaccia Wine : Variations During Biological Ageing

Variations in total polyphenols and in some esterified and free phenolic acids, caused by flor formation in the ageing process of “Vernaccia di Oristano”, were studied using HPLC analysis. The experiments showed that “Vernaccia di Oristano” has a much higher quantity of total polyphenols than other white wines and that this value decreases when the wine is inoculated with flor yeasts. It was also noted that the quantity of free cinnamic acids and of their tartaric esters is very low and that contact between wine and yeast causes an increase in the former and a decrease in the latter. The greatest interactions were recorded between 1043 and AMBRA strains, and trans-p-feruloyl tartaric acid and trans-2-S-glutathionyl caffeoyl tartaric acid (GRP). With inoculated samples the variations observed in total polyphenols corresponds to a sharp decrease of absorbency at 420 nm. The decreases in Optical Density and total polyphenols do not, however, appear to be correlated.