engleski

DIFFERENTIATION OF GEOGRAPHICAL ORIGIN OF CV. MALVAZIJA ISTARSKA WINES BY MULTIELEMENTAL ANALYSIS

Malvazija istarska (Vitis vinifera L.), the most important autochthonous grape in Croatian viticulture sub-region of Istria, has a great potential to produce high-quality white wines. It is the most widespread cultivar on peninsula of Istria and the second most widespread in Croatia. The composition of wine is influenced by many factors related to the specific area of production: grape varieties, soil characteristics, environmental conditions, culture, winemaking, transport and storage. Numerous articles covering the determination of the geographical origin of wine have appeared in the literature over past twenty years. There are indications that wine elements might be valuable for determination of the wine origin. In order to identify winegrowing regions, typical elemental patterns must be analyzed, because element concentrations in wine can reflect elemental composition of the soil in the vineyard. The objective of this work was to study the relationship between selected elements content of Malvazija istarska wines and their geographic origin. This study was performed on thirty six Malvazija istarska wines which were undergoing the procedure of placing of the market. Wines were originated from viticulture zone: CII, viticulture region: Coastal Croatia, sub-region: Croatian Istria, vineyards: eastern, western and central Istria. The measurements of selected elements content (Al, Ca, Co, Cu, Fe, K, Mg, Mn, Na, Pb and Zn) were performed with a sequential inductively coupled plasma-optical emission spectrometer. The concentrations of each element expressed as mean value (mg/L) were: Al (1.04), Ca (75.2), Co (0.006), Cu (0.06), Fe (1.24), K (678.5), Mg (78.8), Mn (1.17), Na (23.7), Pb (0.05) and Zn (0.48). A study of the data structure by virtue of principal component analysis (PCA) was carried out to establish whether wines from different wine producing regions constitute distinctive, well-defined groups. Principal component analysis was performed for all wines and variables (elements) to determine whether vineyard of origin had influenced the elements profile. In this context, 11 selected elements posed as the investigated variables, while wine samples posed as the cases under investigation. The first two factors (PC1 and PC2) represent satisfactory result of 42, 6 % of the initial data variability. Elements Pb, Co, Ca and Mn had strong negative correlation with PC1 while Al and Na showed also strong negative correlation but with PC2. Elements K and Fe positively correlate to PC2. Although there are indications that some elements can characterized individual vineyard, but assessed higher linkage remain on the level of the single wine. It can be explained by proximity of the investigated vineyards and isolated micro climate of Istria peninsula.

geographical origin, cv. Malvazija istarska, multielemental analysis

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