Changes in the Composition of Aroma and Phenolic Compounds Induced by Different Enological Practices of Croatian White Wine

Abstract

The aim of this research was to investigate the effects of pre-fermentative maceration, Saccharomyces and non-Saccharomyces yeasts during alcoholic fermentation, and antioxidant additions (sulfur dioxide and glutathione) at bottling on the compositions of aroma and phenolic compounds of white wine Pošip (Vitis vinifera L.). Additionally, for the fi rst time the insight in volatile thiol precursors in Pošip grape was given, wherein higher concentrations of glutathionylated thiol precursors in comparison to cysteinylated ones were determined. Regarding the applied practices, signifi cant differences among produced wines were established: pre-fermentative maceration resulted in a decrease of 3-sulfanylhexyl acetate (3SHA) and a slight increase of C6 compounds; indigenous yeasts produced higher concentrations of terpenes and esters, while sequential fermentation with Torulaspora delbrueckii also infl uenced higher concentrations of esters. Most abundant phenolic compound was caffeic acid, except for wine produced by indigenous yeasts where trans-caftaric acid was predominant. Finally, combination of higher SO 2 and glutathione resulted in higher concentrations of thiols.

Influence of the Presence of Grape Skins during White Wine Alcoholic Fermentation

“…However, for some winemaking processes, oenological practices that encourage the extraction of different compounds that will influence the chemical composition of the wine and its sensory properties, such as terpenes and aromatic precursors (amino acids, fatty acids, etc.) from the skins to the must are introduced to the must [5]. In this sense, the aromatic complexity of the white wine depends on factors such as the grapevine variety used in the production (primary and varietal aromas), the aromas produced during fermentation (secondary) [6] and the evolution of these aromas during ageing (tertiary) [7][8][9].…”

Sortni tioli u vinu Pošip

“…Nevertheless, the concentrations of precursors and thus of varietal thiols in Pošip wine could possibly be increased if the grapes were harvested at their full maturity. The grapes used in this study yielded a relatively low alcohol content (Table 1) for wines from this grape variety, considering previous studies reporting values higher than 13 vol% (Tomašević et al, 2017;Jagatić Korenika et al, 2019;Tomašević et al, 2019;Radeka et al, 2022).…”

“…However, other grape varieties such as Scheurebe, Macabeo, Gewurztraminer, Riesling, Muscat, Colombard, Petit Manseng, and Tokaj have also been reported to contain detectable concentrations of 4MSP (Roland et al, 2011). In addition, a wide range of concentrations (0 -48 ng L -1 ) was detected in Pošip wines (Tomašević et al, 2017;Tomašević et al, 2019), suggesting its importance for the varietal character of wine from this grape variety. The concentrations of 3SH in the studied Pošip wines are shown in Figure 2.…”

“…3SH is the most abundant thiol in wines, its concentration ranging from below the sensory threshold (60 ng L -1 ) to 12822 ng L -1 (Tominaga et al, 1998). This thiol has been detected in a wide range of varietal wines such as Sauvignon Blanc, Petit and Gros Manseng, Semillon, Petite Arvine, Melon B. and Bacchus, Verdejo, and Koshu (Roland et al, 2011), as well as in Pošip wines (Tomašević et al, 2017;Tomašević et al, 2019). As for the sensory effects of this thiol on the studied Pošip wines, it can be concluded that 3SH contributes to the varietal character of all studied wines with grapefruit and passion fruit nuances (Tominaga et al, 1998), as the detected concentrations were above the sensory threshold.…”