Glasnik Zaštite Bilja, Vol. 38 No. 5, 2015.
Original scientific paper
Effects of harvest time and maceration temperature on polyphenolic content of Frankovka (Vitis vinifera L.) grapes and wines
Ana-Marija Jagatić Korenika
; Agronomski fakultet, Sveučilište u Zagrebu
Ivan Naletilić
Marin Mihaljević Žulj
; Agronomski fakultet, Sveučilište u Zagrebu
Ivana Puhelek
; Agronomski fakultet, Sveučilište u Zagrebu
Ana Jeromel
Abstract
The phenolic maturity of grapes is greatly affected by the harvest time which is, along with wine technology, one of the most important factors in the production of high quality red wine. The traditional production of red wine that combines simultaneous fermentation with maceration process results in wine enriched with polyphenolic compounds, especially flavanols that can contribute to greater bitterness and astringency. Applying cold maceration before fermentation can result in wine with more anthocyanins that influence the colour intensity and result in more intensive aroma due to more sufficient extraction of primary aromas and aroma precursors. At the same time, lower temperatures reduce the extraction of harsh flavanols.
The objective of this research was to determine the influence of harvesting date and maceration temperature on polyphenolic maturity and the quality of Frankovka grapes and wines in the winegrowing area of Srijem, the sub region of Podunavlje. The study was carried out on the 2011 vintage. Total phenols, flavonoids, flavanols, anthocyanins, individual organic acids and general wine composition were analyzed. Different harvesting dates affected both polyphenolic composition and concentration. Based on the results, we have determined that the highest concentration of total phenols and anthocyanins was on the second harvesting date (5 October). Harvest date and different maceration type affected the general and polyphenol composition of wine. Wines produced from grapes picked on the first harvesting date (20 September) had higher levels of extract without sugar, ash, FAN and total acidity, as well as total phenols, flavanols and anthocyanins concentrations, regardless of the type of maceration. Wine produced using the traditional method had higher concentration of tartaric acid. The wine produced from grapes picked on the first harvesting date on which cold maceration was applied had higher levels of total anthocyanins.
Keywords
harvesting date; phenolic maturity; cold maceration; anthocyanins; Frankovka
Hrčak ID:
162365
URI
Publication date:
23.10.2015.
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