Original scientific paper
Analysis of aroma of white wine (Vitis vinifera L. Pošip) by gas chromatography-mass spectrometry
Marina Tomašević
orcid.org/0000-0001-5281-5541
; Prehrambeno - biotehnološki fakultet
Natka Ćurko
orcid.org/0000-0003-0514-9077
; Prehrambeno - biotehnološki fakultet
Leo Gracin
; Prehrambeno - biotehnološki fakultet
Karin Kovačević Ganić
orcid.org/0000-0003-0250-4758
; Prehrambeno - biotehnološki fakultet
Abstract
The aroma is one of the main characteristics that define the differences among the wines and it is affected by the numerous possible variations in wine’s production, both in viticulture and in winemaking (Swiegers et al, 2005). Compounds derived from grapes are responsible for so-called varietal aroma, whereas monoterpenes, norisoprenoids, C6 compounds and varietal thiols are main representatives. Varietal thiols, namely 4-mercapto-4-methyl-pentan-2-one (4MMP), 3-mercaptohexanol (3MH) and 3-mercaptohexylacetate (3MHA) are highly aroma active compounds, responsible for the tropical flavor of wines, and their positive contribution to the aroma of wines made from several grape varieties has already been proven (Tominaga et al, 1998, Murat et al, 2001; Álvarez-Pérez et al, 2012). These compounds belong to the class of varietal aromas because, despite they result from the cleavage of odorless precursors present in grapes or musts by yeast enzymes during alcoholic fermentation they are not product of yeast metabolism (Roland et al, 2011).
In wine, aroma compounds are usually dominated by fermentation products, given that these compounds are present in the highest concentrations (Romano et al, 2003). Alcoholic fermentation increases the chemical and aroma complexity of wine by assisting in the extraction of compounds from solid parts present in grape musts, modifying some grape derived compounds and producing a large amount of yeast metabolites, some of which are aroma compounds (Lambrecht and Pretorius, 2000). Consequently, different yeast populations or strains used for alcoholic fermentation may result with different aroma characteristics of produced wines. Grape juice fermentation can either be natural, conducted by the microflora present in the grapes and in the winery, or inoculated with commercial Saccharomyces cerevisiae strain (Lambrecht and Pretorius, 2000). Inoculation minimizes the influence of wild yeast on wine quality and produces wines with consisted quality with predictable and desired characteristics. On the other hand, spontaneous fermentation may result in a significant and favorable effect on aroma development and in a new wine styles production.
Final aroma of wine is influenced by the chemical reactions that occur during wine aging and storage. During that period, oxidative processes lead to the loss of some characteristic aroma compounds and the appearance of new and distinctive aromas of older wines and/or atypical ones associated with wine deterioration (Escudero et al, 2002; Lambropoulos and Roussis, 2007). In order to preserve wine against oxidative degradation, the addition of antioxidants prior to bottling is widespread practice; whereas addition of glutathione (GSH) has been suggested since GSH exhibited increased protection toward important aroma compounds (Ugliano et al, 2011).
Keywords
wine aroma; yeast strain; antioxidants; Pošip; sensory analysis
Hrčak ID:
177245
URI
Publication date:
20.12.2016.
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