Impact of Alternative Skin Contact Procedures on the Aroma Composition of White Wine

Abstract

Zelen, Ribolla Gialla and Malvasia Istriana, grapes from the Vitis vinifera (L.) varieties, were subjected to four processes involving grape skin contact. Fresh and fruity young wines were produced by adding 6% or 12% grape berries, respectively, during alcoholic fermentation, freezing the pomace (Fp) and the freezing whole grapes (Fg). Wine-free volatile aromatic compounds were determined using two extraction techniques coupled to gas chromatography (GC). These aromatic compounds and wine standard chemical parameters were compared to control wines produced without skin contact. Esters, higher alcohols, terpenes, volatile phenols and C 6 alcohols proved to be the most important sensorial odorants in wines. Both the content of aromatic compounds and the odour activity values showed some positive effects from skin contact. The freezing of the grapes and addition of 12% grape berries proved most effective for Zelen and Malvasia Istriana, producing a more intensive fruity and floral odour, a less intensive solvent odour and additional freshness. The same processes resulted only in additional fruitiness or a less intensive solvent odour in Ribolla Gialla while the lowest concentrations of grape derived terpenes were achieved for this variety. The three varieties were most affected by freezing processes. During the sensorial evaluation, the wines that had been subjected to skin contact were generally preferred to the control wines.

Differentiation of Commercial PDO Wines Produced in Istria (Croatia) According to Variety and Harvest Year Based on HS-SPME-GC/MS Volatile Aroma Compounds Profiling

“…Nerol emerged as a consistent diff erentiator of Malvazij a and Chardonnay, with significant diff erence determined in both years. The concentrations and the composition of monoterpenes in Malvazij a wines were generally in fair agreement with those reported previously: their content was moderate but signifi cant, with linalool followed by geraniol as the most abundant (9,(22)(23)(24)(25). Although relatively high concentrations of linalool were found in particular Chardonnay wines from other world regions (up to 142 μg/L), wines from this variety are mostly defi cient in monoterpenes (30), and the results of this study confi rmed it.…”

“…Because of the lack of objective scientific information, knowledge on the varietal typicity of wines from native Croatian grape varieties is still on an informal level. For example, there is published data on the composition of wines made from Malvazij a istarska, the most spread and important native white grape variety in Croatia grown principally in the region of Istria (9,(22)(23)(24)(25), but the volatile compounds and their particular concentrations, indicators of its varietal origin and drivers of its varietal typicity, on the basis of which it might be distinguished and diff erentiated from other monovarietal white wines, are still unknown. On the other hand, Chardonnay is a globally spread and known variety, and its wine aroma has been investigated extensively (26)(27)(28)(29)(30).…”

Phenol and Aroma Composition of White Wines Produced by Prolonged Fermentative Maceration and Maturation in Wooden Barrels

“…The eff ects of maceration known up to date, such as increased amounts of phenols and primary aromas, higher dry extract, and reduced acidity, were deter mined in experiments with short-term, usually prefermentative white grape mash maceration (1)(2)(3)(4)10). Published studies that have investigated prolonged maceration in white winemaking are only a few (7,11,12), and the chemical composition of such wines is almost completely unknown.…”

Maceration and Extraction of Grape Components

“…Other related technologies that have been studied include ultrasound [31], microwave [32], and freezing (cryomaceration) [33], with varying and modest effects in wine and model systems. However, cryomaceration of the whole or crushed fruit has been shown to increase the extraction of volatile aroma substances [34].…”