Polyphenolic composition of wine Teran

Polifenolne komponente vina imaju važnu ulogu u formiranju boje bobica grožđa, arome, okusa i nutritivne vrijednosti. U posljednje vrijeme zanimanje za te supstancije potaknuto je brojnim dokazima o njihovim pozitivnim učincima na zdravlje čovjeka. Cilj ovog rada bio je odrediti polifenolni sastav vina Teran. Uzorci za analizu uzeti su sa tri istarska vinogorja (Istočno, Zapadno i Centralno). Primjenom spektrofotometrijskih metoda analize određen je udio ukupnih fenola, ukupnih i slobodnih antocijana, ukupnih i neantocijanskih flavonoida, provedena je reakcija s vanilinom (određivanje flavanola) te određivan tonalitet i intenzitet boje. Tehnikom tekućinske kromatografije visoke djelotvornosti (HPLC) određen je udio flavan-3-ola, flavonola, hidroksicimetnih i hidroksibenzojevih kiselina, stilbena i rutina. Rezultati provedenih analiza pokazali su da su najveće vrijednosti za određivane fenolne spojeve bile u vinima Zapadnog vinogorja (prosječno 362 mgL-1), a najmanje u vinima Istočnog vinogorja (prosječno 348 mgL-1). To zapravo potvrđuje da na kemijski sastav vina utječu stupanj zrelosti, kvaliteta grožđa kao i agroklimatski uvjeti pod kojima se grožđe uzgaja.Polyphenolic components of wine have an important role in the formation of grape berry color, aroma, flavor and nutritional value. Recently, interest in these substances is being driven by the wealth of evidence about their positive effects on human health. The aim of this study was to determine the polyphenolic composition of wine Teran. Samples for analysis were taken from three Istrian wine regions (East, West and Central). By applying the spectroscopic method of analysis, the following has been determined: the amount of total phenols, total and free anthocyanins, total and nonathocyanin flavonoids. Reaction with vanilin (determination of flavanols) was carried out and the tonality and color intensity were determined. Using the technique of high performance liquid chromatography (HPLC) it was possible to determine the proportion of flavan-3-ols, flavonols, hidroycinnamic and hidroksybenzoic acids, stilbenes and routine. The results of the analysis showed that the maximum values of determined phenolic compounds were in wines from the Western vineyards (average of 362 mgL-1), and the minimum values were in wines from the Eastern vineyards (average of 348 mgL-1). This fact confirms that the chemical composition of wine affects the degree of maturity, as grape quality and agroclimatic conditions under which the grapes are grown