Pre-Fermentation Water Addition to High-Sugar Shiraz Must: Effects on Wine Composition and Sensory Properties

Dual-temperature dual-state fermentation: A novel approach to improve aroma and color characteristics of Marselan wines

This study examined the effects of the Dual-Temperature Dual-State Fermentation (DTSF) technique on the chemical and sensory characteristics of industrial-scale 'Marselan' wine. Compared to the control wine, DTSF wine exhibited greater color intensity (chroma) attributed to higher levels of anthocyanin derivatives and copigments, along with a lower pH. Furthermore, DTSF wine retained higher concentrations of grape-derived aroma volatiles, including C6/C9 compounds, terpenoids, and norisoprenoids, and elevated levels of fermentation-derived esters (notably ethyl esters), contributing to a more intense fresh fruit aroma. Additionally, the DTSF technique had a minimal impact on condensed tannins and mouthfeel. This study confirms the viability of the DTSF technique for producing high-quality red wines and highlights its potential for the production of wines with diverse sensory profiles.

Effect of dehydration of Syrah grape berries on the aging potential of fortified sweet wines in Ningxia of China

Many of wines from western China suffer from the short lifespan of aging. This study was conducted to investigate the effects of grape dehydration on aging potential of fortified sweet wines. Compared with the control wine (CK), dehydration significantly raised the sugar, organic acids and acetic esters content of G20 and G40 wines (made by 20 % and 40 % weight loss grapes). Dehydration also enhanced the stability of anthocyanins and the color of wines. After 24 months of aging, G20 had the highest monomeric anthocyanin content, and the variations of a ⁎ , b ⁎ and H ⁎ ab values were lowest in G40. Furthermore, dehydrated samples presented better aging stability with the improved sensory characteristics such as stronger black fruit fragrance, fuller body and richer aftertaste. In general, Syrah fortified sweet wine provides a new option for high quality wines with stable color, concentrated aroma, rich taste, and high aging potential in Ningxia of China.

Effects of Saignée and Bentonite Treatment on Phenolic Compounds of Marquette Red Wines

To improve the phenolic extraction and color stability of red wine made from cold-hardy grapes, two winemaking practices, saignée and bentonite, were applied separately and in combination on Marquette grapes at crushing. The effects of these winemaking strategies on Marquette wine’s basic chemical properties, monomeric and polymeric phenolic compounds were studied, as well as the development of color characteristics from crushing to 5 months of aging. The saignée (9% juice run-off) treatment showed little impact on the phenolic content of the finished wine, but showed an increase in color intensity. A hue shift towards an orange-yellow tone was observed in the bentonite-treated wines, which was associated with a loss of monomeric anthocyanins. The combination of saignée and bentonite showed less impact on removing anthocyanins and wine color, and increased phenolics content, therefore improving the extraction of non-anthocyanins monomeric phenolics. Although this combination treatment led to the highest concentration of tannin content after pressing, this difference between the control and other treatments disappeared over time. These results suggested that the interactions between tannins and other wine compounds still occur after removing proteins in Marquette wines.

Techniques for Dealcoholization of Wines: Their Impact on Wine Phenolic Composition, Volatile Composition, and Sensory Characteristics

The attention of some winemakers and researchers over the past years has been drawn towards the partial or total dealcoholization of wines and alcoholic beverages due to trends in wine styles, and the effect of climate change on wine alcohol content. To achieve this, different techniques have been used at the various stages of winemaking, among which the physical dealcoholization techniques, particularly membrane separation (nanofiltration, reverse osmosis, evaporative perstraction, and pervaporation) and thermal distillation (vacuum distillation and spinning cone column), have shown promising results and hence are being used for commercial production. However, the removal of alcohol by these techniques can cause changes in color and losses of desirable volatile aroma compounds, which can subsequently affect the sensory quality and acceptability of the wine by consumers. Aside from the removal of ethanol, other factors such as the ethanol concentration, the kind of alcohol removal technique, the retention properties of the wine non-volatile matrix, and the chemical-physical properties of the aroma compounds can influence changes in the wine sensory quality during dealcoholization. This review highlights and summarizes some of the techniques for wine dealcoholization and their impact on wine quality to help winemakers in choosing the best technique to limit adverse effects in dealcoholized wines and to help meet the needs and acceptance among different targeted consumers such as younger people, pregnant women, drivers, and teetotalers.