Effect of Different Maceration Treatments on Free and Bound Varietal Aroma Compounds in Wine of Vitis vinifera L. cv. Malvazija istarska bijela
Sanja Radeka1*, Stanka Herjavec2, Đordano Peršurić1, Igor Lukić1 and Barbara Sladonja1
1Institute of Agriculture and Tourism, Karla Huguesa 8, HR-52 440 Poreč, Croatia
2Faculty of Agronomy, University of Zagreb, Svetošimunska 25, HR-10 000 Zagreb, Croatia
Article history:
Received February 22, 2007
Accepted July 13, 2007
Key words:
Malvazija istarska wines, maceration at 20 °C, cryomaceration, varietal aroma, monoterpenes, phenols
Summary:
During a two-year study, the effect of different grape mash maceration treatments (skin contact at 20 °C for 10, 20 and 30 h) and cryomaceration (skin contact at 7 °C for 10, 20 and 30 h) on the concentration of free and bound monoterpenes and total phenols in Malvazija istarska wine (the most spread white wine variety in Istria) was monitored. Monoterpenic alcohols linalool, α-terpineol, citronellol, nerol and geraniol were determined by gas chromatography after isolation on octadecylsilica (C18) sorbent and elution with pentane/dichlorometane ratio of 2:1, while total phenols were determined spectrophotometrically with Folin-Ciocalteau reagent. Sensory evaluation of wines was performed using the Buxbaum method. The obtained results show that linalool and geraniol are the most abundant monoterpenes in Malvazija istarska, and that grape mash maceration treatments cause significant increase of free and bound monoterpene concentrations compared to those in control treatment wine obtained without maceration. The content of phenols, which are subject to oxidation, was found to be significantly lower in wines produced by cryomaceration treatments, while in those produced by maceration at 20 °C the concentration of total phenols increased proportionally with the duration of maceration, negatively influencing wine quality by causing higher colour intensity and bitter taste.
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