Different application dosages of a specific inactivated dry yeast (SIDY): effect on the polysaccharides, phenolic and volatile contents and color of Sauvignon blanc wines

Aim: The aims of this study were to (i) study the effect of different application dosages of a commercial specific inactivated dry yeast (SIDY) on several compounds (polysaccharides, phenolic and volatile compounds) and attributes (color parameters) related to the quality of white wines, and (ii) acquire better knowledge about the use of different dosages of SIDY in white wines with the objective to improve their quality. Methods and results: Three different dosages were applied (10, 20 and 40 g hL-1). Treated wines were followed after a contact time period of two months and after a bottle aging period of three months. Total phenolic content, color intensity, CIELab coordinates, polysaccharides, low molecular weight phenolic compounds and volatile compounds were evaluated. Conclusions: Higher dosages of this SIDY resulted in a greater release of polysaccharides into the wine. In parallel, a positive effect on the reduction or prevention of wine oxidation was observed due to the interaction with certain phenolic compounds. The application of the highest dosage seems to lead to an adsorption or retention effect of the major identified volatile compounds. This effect seems to be more evident after the contact time period than after the bottle storage period. Significance and impact of the study: This study can contribute to improve our knowledge on how applying different dosages of SIDY affects the physical and chemical quality of white wines

Influence of Maturity and Vineyard Location on Free and Bound Aroma Compounds of Grapes from the Pais Cultivar

Some of the volatile compounds present in grapes give wine is its unique and genuine characteristics. “Terroir” and berry maturity are considered to be the main influences on the expression of these characteristics. This work was undertaken to establish the specific characteristics that define Vitis vinifera cv. País, based on its aromatic profile and free and bound compounds (glycosides), and to assess the effects of location and maturity. Free and bound volatile compounds presented significant differences in the three locations studied. The total amount of free alcohols, acids and ketones depended on the location. During ripening, the amount of aroma precursors increased in all chemical groups in every location studied, and they were found mainly in the skins. With reference to free volatile compounds, it was found that cis-2- hexenol could be a good candidate to assess maturity, and that terpene content seemed to be strongly related to the vineyard location and cultivar conditions. Also, data analysis showed that the free aroma profile seemed to be influenced more by the maturity of the grapes and the bound aroma fraction more by the location

Different application dosages of a specific inactivated dry yeast (SIDY) : effect on the polysaccharides, phenolic and volatile contents and color of Sauvignon blanc wines

Aim: The aims of this study were to (i) study the effect of different application dosages of a commercial specific inactivated dry yeast (SIDY) on several compounds (polysaccharides, phenolic and volatile compounds) and attributes (color parameters) related to the quality of white wines, and (ii) acquire better knowledge about the use of different dosages of SIDY in white wines with the objective to improve their quality. Methods and results: Three different dosages were applied (10, 20 and 40 g hL-1). Treated wines were followed after a contact time period of two months and after a bottle aging period of three months. Total phenolic content, color intensity, CIELab coordinates, polysaccharides, low molecular weight phenolic compounds and volatile compounds were evaluated. Conclusions: Higher dosages of this SIDY resulted in a greater release of polysaccharides into the wine. In parallel, a positive effect on the reduction or prevention of wine oxidation was observed due to the interaction with certain phenolic compounds. The application of the highest dosage seems to lead to an adsorption or retention effect of the major identified volatile compounds. This effect seems to be more evident after the contact time period than after the bottle storage period. Significance and impact of the study: This study can contribute to improve our knowledge on how applying different dosages of SIDY affects the physical and chemical quality of white wines.CONICYT-PAI, República de Chile (concurso nacional inserción en el sector productivo, convocatoria 2014) No. 781403003FONDECYT (República de Chile) 11140275FONDECYT (República de Chile) 1140882FONDEQUIP (República de Chile) EQM- 13012

Characterization and Control of Oxygen Uptake in the Blanketing and Purging of Tanks with Inert Gases in the Winery

This work presents the study of the effectiveness of different inert gases applied during racking to prevent oxygen uptake by wine. Inert gases were used for the purging of empty tanks and hoses before the start of each racking, as well as for blanketing in the full racked tank. After analyzing these operations with the different inert gases, the required volumes of each gas were optimized. The CO2:Ar (20:80) mixture proved to be the most effective for the complete purging of the empty tank, while CO2 was the most cost-effective gas. Purging the empty tank with 25% vessel volume gas was sufficient to achieve useful inerting with all the gases studied, as well as to maintain low levels of dissolved oxygen (DO) in the wine filling the tank. Applying 0.5 of vessel volume of Ar, CO2:Ar (20:80), and CO2 gases during blanketing allowed the headspace oxygen (HSO) of the racked tank to be protected throughout. During the racking of a white wine in a commercial winery, Ar showed the highest efficiency, compared to N2, for both the inerting of empty hoses and destination tank and for maintaining low levels of DO and HSO in the tank

Effectiveness of fibers from “Cabernet Sauvignon” (vitis vinifera) pomace as fining agents for red wines

Recent findings have highlighted the potential of fibers from grape cell wall material to be fining agents for red wines as alternatives to animal-derived proteins. The affinity of those fibers for grape proanthocyanidins (also known as condensed tannins) seems to depend on the initial phenolic composition of the wines to be fined and on the applied dose of fibers. In the present work, "Cabernet Sauvignon" grapes were harvested at three different maturity levels and used for making red wine. The pomaces of the three vinifications were used to obtain the cell wall fibers. Each wine was treated with the three purified fibers at two different doses (0.2 g/L and 2.5 g/L) under winery-like conditions in order to check the potential of fibers as fining agents. Color and phenolic composition of the treated wines were determined immediately after the treatments and after four and nine months of wine bottle ageing. The effectiveness of the fining strongly depends on the initial wine matrix. Wines treated at high doses had lower color density and higher hue than control untreated wines. Small differences were observed in the phenolic content of the treated wines. Those differences were dose dependent and almost disappeared after several months of ageing. The maturity of the grapes from which the fibers came had no influence on the effectiveness of the fining. Additionally, there was no evidence of polysaccharide release from the fibers to the wine.CONICYT-Chile (FONDECYT) 3150322 1140882 1116051

Alternative Woods in Oenology: Volatile Compounds Characterisation of Woods with Respect to Traditional Oak and Effect on Aroma in Wine, a Review

The interest of winemakers to find new woods that can give their wines a special personality and the need for cooperage wood have led to the use of other woods than traditional oak. The aroma of wines is undoubtedly one of the quality factors most valued by consumers. Volatile compounds from wood are transferred to wines during ageing. The type and quantity of aromas in wood depend on several factors, with the species, origin and cooperage treatments, particularly toasting, being very important. The transfer of volatile compounds to the wine depends not only on the wood but also on the wine itself and the type of ageing. This review therefore aims to recapitulate the volatile composition of alternative oenological woods at different cooperage stages and to compare them with traditional woods. It also summarises studies on the effect of wine aromas during ageing both in barrels and with fragments of alternative woods. In summary, it is observed that both woods and wines aged with alternative species of the Quercus genus present the same volatile compounds as traditional ones, but differ quantitatively; however, non-Quercus woods also differ qualitatively

Correction: Del Barrio-Galán, R., et al. Evaluation of Yeast Derivative Products Developed as an Alternative to Lees: The E ect on the Polysaccharide, Phenolic and Volatile Content, and Colour and Astringency of Red Wines. Molecules 2019, 24, 1478

The authors wish to make the following corrections to this paper [...

Evaluation of Yeast Derivative Products Developed as an Alternative to Lees: The Effect on the Polysaccharide, Phenolic and Volatile Content, and Colour and Astringency of Red Wines

Due to the increase of the use of yeast derivatives (YDs) in winemaking to improve the technological and sensory properties in wines, in this work we evaluated the effect of the post-fermentation application of different yeast derivative products on the physical and chemical properties and astringency of red wines during two consecutive harvests. A commercial and two experimental new yeast derivatives were applied at a medium‒high dosage (30 g/hL). The addition of different yeast derivatives in red wine increased the concentration of different polysaccharide fractions and, therefore, the total polysaccharide content, producing a decrease in the duration of the wine astringency perception over time. The use of yeast derivatives could produce an adsorption/clarification and/or protective effect on the phenolic compounds. However, it did not produce an important modification of the colour parameters. An intensification or a lower decrease of the most volatile compound groups was produced, but it depended on the YDs and yeast strain used in fermentation and post-fermentation processes

The diversity of effects of yeast derivatives during sparkling wine aging

Producción CientíficaThis study shows the monitoring of the physical, chemical and sensorial changes that occur in the sparkling wine along 18 months of aging due to different typology yeast-derived products; dry inactivated yeast from Saccharomyces (Saccharomyces cerevisiae) and non-Saccharomyces (Torulaspora delbrueckii) yeast strains, yeast autolysate, and yeast protein extract tested at two different doses. The addition of 5 g/hL yeast protein extract and inactivated yeast from T. delbrueckii helped to preserve esters in wines with 9 and 18 months of aging on lees. The addition of yeast autolysate achieved greater polysaccharide enrichment and gave rise to sparkling wines with the highest antioxidant activity. Effects on foaming properties were quite different depending on the aging time. Despite this, sparkling wines treated with 10 g/hL of yeast autolysate and Optimum White™ generally exhibited the highest foamability and foam stability. Further experiments with higher doses are needed to observe clear effects on sensory profile