Wine Phenolic Composition Research Articles

Organic mulches slightly influence the wine phenolic profile and sensory evaluation

Organic mulching offers numerous agronomical benefits, but its impact on wine quality remains unclear. This study assessed the effect of this practice on wine physicochemical, phenolic composition and sensory properties. Over four years, three organic mulches (grape pruning debris (GPD), straw (STR), and spent mushroom compost (SMC)) and two conventional practices (tillage (TILL) and herbicide (HERB)) were evaluated in two locations. Wines from mulching treatments exhibited higher pH, potassium, hue, and lower tartaric acid. Moreover, the SMC mulch treatment showed lower amounts of wine anthocyanins, flavonols and hydroxycinnamics, probably due to increased nutrient availability. However, no differences were detected in the wine sensory analysis. Therefore, organic mulches could be alternative practices to mitigate the consequences of climate change without significant impact on young wine's phenolic profile and sensory properties compared to HERB and TILL conventional soil management. However, future studies should focus on wine evolution during aging.

Potential Use of Torulaspora delbrueckii As a New Source of Mannoproteins of Oenological Interest.

In this work, three MP extracts obtained from Torulaspora delbrueckii were added to red wine, and the changes in phenolic composition, color, and astringency were evaluated by HPLC-DAD-ESI-MS, tristimulus colorimetry, and sensory analysis, respectively. The MP extracts modified wine phenolic composition differently depending on the type of MP. Moreover, two MP extracts were able to reduce wine astringency. The fact that the MP-treated wines showed an increased flavanol content suggests the formation of MP-flavanol aggregates that remain in solution. Furthermore, the formation of these aggregates may hinder the interaction of flavanols with salivary proteins in the mouth. The effect of these MPs might be associated with their larger size, which could influence their ability to bind flavanols and salivary proteins. However, one of the astringent-modulating MPs also produced a loss of color, highlighting the importance of assessing the overall impact of MPs on the organoleptic properties of wine.

Influence of Quercus alba oak geographical origin on the colour characteristics and phenolic composition of Tempranillo wines

AbstractThis research analyzes the influence of Quercus alba barrels from four different forests of the USA [Missouri (M), Ohio (O), Kentucky (K) and Pennsylvania (P)] on the colour parameters, phenolic composition, and visual and gustatory sensory characteristics of 12 Tempranillo red wines from different wineries after 12 months of aging. Oak origin significantly affected the colour parameters of the wines, except for tonality, and the content of anthocyanins, stilbenes and ellagitannins but had little effect on the rest of the phenolic compounds. Wines aged in K and O barrels showed the highest content of ellagitannins. Wines aged in P barrels had the lowest content of phenolic compounds and colour intensity (CI), while K and O barrels produced the highest levels of ellagitannins. K wines were the best value in the global perception of the taste analysis. The influence of the barrel origin on the phenolic composition of the wines was also evaluated according to their initial phenolic composition. Wines with the highest initial CI and phenol content also showed the highest content of ellagitannins after barrel aging. When aging wines with high CI and phenol content, M barrels provided the wines with the highest content of ellagitannins.

Forecasting wine phenolic composition from infrared spectra of grapes extracts and monitoring of fermentations with optimised time-specific prediction models

Incorporating monitoring and forecasting technologies has the potential to enhance the different aspects of winemaking. By monitoring certain chemical parameters, it is possible to evaluate the progress of the fermentation and phenolic extraction, while also detecting deviations from expected behaviour. This study aims to investigate the development of a rapid forecasting method and different strategies to improve the accuracy of process monitoring. The first part involves the introduction of partial least squares (PLS) calibration models able to forecast the trajectories of phenolic extraction during fermentation using grape extract spectra. Additionally, novel methods for reoptimizing calibration models are proposed, with the intention of increasing the prediction accuracy. Whilst this method is transferable to PLS models, principal component regression (PCR) models were used instead as a more simplistic way to test the new methods. First, dynamic PCR linear regression coefficients were adapted over time to capture the compound evolution in the wine matrix. Secondly, PCR calibration models were reoptimized using interpolated spectral and reference data. The forecasting PLS calibration models have shown promising results for total anthocyanin content (mg/L), colour density, polymeric pigments (mg/L), MCP tannins (mg/L), and total phenolic index with overall R2 values on the validation set above 0.6, and low RSMEV values. Using interpolated data to re-optimise models was found to be more effective than global models or those using the calculated regression coefficients methods for predicting the concentration of a particular compound at a certain time point. While R2 values are suboptimal for all considered PCR models, in 72% of the cases analysed, the interpolation method for re-optimisation showed RMSEV values between 6% and 83% lower than those reported for a more traditional PCR model and other re-optimisation strategies. Interpolated models have shown consistency in predicting values, along with good performance metrics, indicating that they could be applied to samples for which calibration models do not exist.

Effects of post-fermentation addition of green tea extract for sulfur dioxide replacement on Sauvignon Blanc wine phenolic composition, antioxidant capacity, colour, and mouthfeel attributes

This study examines the feasibility of replacing SO2 in a New Zealand Sauvignon Blanc wine with a green tea extract. The treatments included the control with no preservatives (C), the addition of green tea extract at 0.1 and 0.2 g/L (T1 and T2), and an SO2 treatment at 50 mg/L (T3). Five monomeric phenolic compounds were detected in the green tea extract used for the experiment, and their concentrations ranged in the order (−)-epigallocatechin gallate > (−)-epigallocatechin > (−)-epicatechin > (−)-epicatechin gallate > gallic acid. At the studied addition rates, these green tea-derived phenolic compounds contributed to ∼70% of the antioxidant capacity (ABTS), ∼71% of the total phenolic index (TPI), and ∼ 84% of tannin concentration (MCPT) of the extract dissolved in a model wine solution. Among wine treatments, T1 and T2 significantly increased the wine's colour absorbance at 420 nm, MCPT, gallic acid and total monomeric phenolic content. TPI and ABTS were significantly higher in wines with preservatives (i.e., T2 > T1 ≅ T3 > C, p < 0.05). These variations were observed both two weeks after the treatments and again after five months of wine aging. Additionally, an accelerated browning test and a quantitative sensory analysis of wine colour and mouthfeel attributes were performed after 5 months of wine aging. When exposed to excessive oxygen and high temperature (50 °C), T1 and T2 exhibited ∼29% and 24% higher browning capacity than the control, whereas T3 reduced the wine's browning capacity by ∼20%. Nonetheless, the results from sensory analysis did not show significant variations between the treatments. Thus, using green tea extract to replace SO2 at wine bottling appears to be a viable option, without inducing a negative impact on the perceptible colour and mouthfeel attributes of Sauvignon Blanc wine.

Agronomic performance and wine phenolic composition of ‘Merlot’ grown in altitude region with different rootstocks

Several studies have reported the influence of rootstocks on grape and wine composition, however, there is considerable variability in the results. The objective of this work was to evaluate the effects of three different rootstocks on vegetative-productive balance and the wine composition of ‘Merlot’. The present work was conducted in the municipality of Painel, during the 2014/2015, 2015/2016 and 2016/2017 vintages. The vegetative, productive, and enological variables of ‘Merlot’ grafted onto ‘Paulsen 1103’, ‘3309 Couderc’ and ‘101-14 Mgt’ rootstocks were evaluated. The ANOVA results showed that‘3309C’ rootstock promoted an increase in the productive indices, and consequently in more adequate vegetative-productive balance for ‘Merlot’ variety compared to the rootstocks ‘Paulsen 1103’ and ‘101-14 Mgt’. The rootstocks ‘3309C’ and ‘101-14 Mgt’ provided more adequate maturation indices for ‘Merlot’. The ‘101-14 Mgt’ rootstock was associated with the highest contents of flavonoid compounds, while the ‘3309C’ rootstock was related to higher contents of non-flavonoid compounds, especially resveratrol.

Effect of postharvest grape dehydration on the phenolic composition of ‘Marselan’ rose wine during aging

This study aimed to determine the effect of grape dehydration on the phenolic composition of ‘Marselan’ rose wines during aging. ‘Marselan’ grapes dehydrated for various times (9, 18, 27 days) under controlled conditions were used to produce rose wines as well as the wines were aged in bottle for 24 months. The phenolic composition of wines was determined through high-performance liquid chromatography (HPLC). It has been observed that wines obtained from dehydrated grapes were rich in phenolic compounds, with an increase in peonidin-3-O-glucoside, malvidin-3-O-glucoside, malvidin-3-O-(6-O-acetyl)-glucoside, vanillic, syringic, (E)-ferulic acids and epicatechin. Besides, the dehydration process promoted the increase of hydroxycinnamic acids and slowed down the loss of flavanols compared to the control wine during bottle storage. Through the orthogonal partial least squares discriminant analysis (OPLS-DA), the evolution of phenolic compounds in wine samples during bottle storage was facilitated by the dehydration of grapes.

Diverse phenolic responses of six varietal wines (Vitis vinifera L.) throughout ageing in contact with a single type of oak barrels

SummaryBarrel ageing is a critical process in wine industry since it produces substantial changes in the chemical composition of wines. The transfer of polyphenols from wood to wine would be influenced by various factors including wood characteristics and storage conditions. The role of the wine matrix in the extraction/modification of polyphenols during wine ageing has been scarcely studied. The objective of this study was to characterise and compare the phenolic composition of six varietal wines (Carménère, Cabernet Franc, Malbec, Petit Verdot, Sangiovese and Tempranillo) during ageing in a single type of oak barrel aiming to learn about the role of the variety on the ageing process. Wine sampling was performed at 3‐month intervals for 1 year. Polyphenol profiles were analysed using spectrophotometric and HPLC‐DAD methods. The study showed that the effect of oak wood ageing on the phenolic composition of wines is highly influenced by the grape variety. Thus, different polyphenol‐associated chemical parameters of oak‐aged wines would be affected by chemical properties of the varietal wines that are present prior to barrel ageing.

Influence of non-irrigation and seasonality on wine colour, phenolic composition and sensory quality of a grapevine (&lt;i&gt;Vitis vinifera&lt;/i&gt; cv. Callet) in a Mediterranean climate

Most vineyards in Mediterranean areas are cultivated using a training system and drip irrigation. However, the increasing risk of water deficit stress due to global warming will mean that viticulture need to adapt to a tougher water-saving policy. Thus, we investigated the effects of total suppression of irrigation on a grapevine (Vitis vinifera cv. Callet) and the phenolic composition and sensory quality of this native red variety wine from the Balearic Islands over three seasons. Significant yield reductions of up to 15.6 %, 17.2 % and 22.2 % were observed in non-irrigated (NI) plants in 2016, 2017 and 2018 respectively, compared to irrigated plants (I); however, wine quality parameters improved. In the years with the highest rainfall (715 mm in 2016 and 799 mm in 2017), NI favoured the enrichment of sugars, anthocyanins and phenolic compounds in the wine and enhanced the development of aromatic components. However, with lower rainfall (524 mm in 2018), the NI treatment appeared to diminish the quality of the wine, particularly affecting the global sensory quality of the wines. Thus, development of specific water strategies tailored to the vineyard, year, vintage and grape variety may regulate the phenolic composition of red wines to meet production goals and reduce total water consumption.

Management tool for oenological decision-making: Modeling and optimization of a hybrid model for fermentative maceration of Cabernet Sauvignon

This work presents a hybrid model for Cabernet Sauvignon (CS) red wine-making that combines mechanistic and data-driven approaches to optimize the fermentation process and improve the quality of red wine. The model incorporates two sub-units representing the interaction between alcoholic fermentation and phenolic extraction, considering factors such as temperature, products addition, draining time, and must composition. To develop and validate the model, a database of 270 industrial CS fermentation from 2017-2021 harvest seasons was collected. The models were calibrated using experimental data, achieving an average R2 of 0.94 for fermentation kinetics model and 45% and 80.9% test accuracy for tannins and anthocyanins predictors, respectively. A multi-objective dynamic optimization problem was formulated and solved to find fermentation operation conditions that optimize simultaneously phenolic quality, process costs and productivity. A similar distribution of the Paretos were obtained for varietal and premium wines. Finally, these tools were packed in a digital platform for practical use in industrial cellars. The models generate the predictions and recipes prescription for each fermentation tank when the pre fermentative juice is analyzed. As a result, it is obtained useful information for wine decision-making like maceration length and wine phenolic composition at least five days in advance.

Characterization of the color parameters and monomeric phenolic composition of ‘Tempranillo’ and ‘Graciano’ wines made by carbonic maceration

The current study aims to gather information about the color-related characteristics and the monomeric phenolic composition of carbonic maceration (CM) wines. The study was conducted over two vintages, with two different grape varieties. Color-related general parameters and wine monomeric phenolic composition were determined in both free-run and press CM fractions and were compared to conventional winemaking (CW). Overall, wines made by CM had lower phenolic content and color intensity. The analysis of wine detailed phenolic composition showed that CM wines were characterized by low contents of anthocyanins and flavonols. In contrast, free-run wine obtained by CM had the greatest concentration of flavanols and hydroxycinnamic acids, probably due to the presence of stems during the fermentation. In conclusion, vinification by CM leads to important differences in wine phenolic composition and, as consequence, on wine color properties. These differences could play an important role in wine sensorial properties and wine aging potential.

Effect of Methyl Jasmonate and Methyl Jasmonate Plus Urea Foliar Applications on Wine Phenolic, Aromatic and Nitrogen Composition

Foliar application has been studied to enhance grape composition and, therefore, wine quality. This work examined, for first time, the effects of foliar applications of methyl jasmonate (MeJ) and methyl jasmonate plus urea (MeJ+Ur) to Tempranillo vineyard on wine phenolic, aromatic and nitrogen composition over two vintages (2019 and 2020). A reduction in alcoholic degree was observed in MeJ and MeJ+Ur wines. The effect of foliar treatments was season-dependent. MeJ and MeJ+Ur wines were characterized, in the first vintage, by a higher content of total acylated anthocyanins, but a low content of total esters, alcohols and acids when compared with control wines. MeJ+Ur wines presented a higher total amino acids content than control and MeJ wines. However, in the second vintage, MeJ and MeJ+Ur wines presented an increase in some non-acylated anthocyanins, but only MeJ+Ur treatment increased the total content of flavonols, flavanols, hydroxycinnamic acids, stilbenes and total amino acids when compared with control wines. MeJ wines presented a low content of esters and acids, whereas MeJ+Ur did not show differences with control wines. Overall, the effect of MeJ+Ur foliar treatment was greater than the effect of MeJ application in order to improve the wine chemical composition.

Impact of rutin and buckwheat (Fagopyrum esculentum) extract applications on the volatile and phenolic composition of wine

The aim of this research is to study the possibility of increasing the quality of red wins made with the Monastrell grape variety. A methodology was established to improve the concentration levels of polyphenol and aroma in these wines. Among flavonoids, the copigmenting effect of rutin stands out, and was tested in both winery and field applications. Buckwheat extract (Fagopyrum esculentum), in which rutin is the main flavonoid, may be of interest for viticulture given its biological activity.This paper focuses on researching the effect of applying the prefermentative vegetable extract of buckwheat (Fagopyrum esculentum) on the concentration of polyphenols and aroma compounds in vineyards. Simultaneously, a study was carried out to compare the effect of pure copigment (rutin) when applied in vineyards and cellars. Traditional vinification was done, plus prefermentative cold maceration.The application of buckwheat extract, and rutin extract to a lesser extent, to Monastrell grapes increased the concentration of malvidin and other anthocyanins, and total anthocyanins. After 12-month storage, no differences were observed in the percentage of copigmented, polymerised and free anthocyanin, the total polyphenol concentration, and the tannin quality parameters like DMACH (aldehyde p-dimethylaminoacimaldehyde) and the Gelatin Index. The concentrations of diethyl succinate, 2 phenylethyl acetate, vanillin and ethyl octanoate increased, while other compounds decreased when the copigment was added. The maceration technique followed during the vinification process had very little effect on polyphenolic compounds. The prefermentative maceration slightly increasing the concentration of total polyphenols, but had no effect on the parameters related to colour, anthocyanin concentration, nature of anthocyanins, their binding state or tannin quality parameters. The results showed that cold prefermentation maceration increased the concentration of some volatile compounds, including alcohols and esters, which should be considered important contributors to Monastrell wine aroma.The combination of the applying buckwheat extract and pure rutin together, and prefermentative cold maceration, positively affects the polyphenolic concentration and increases the concentration of quality volatile compounds.

Interactions of Vitis vinifera L. cv. Pinot Noir grape anthocyanins with seed proanthocyanidins and their effect on wine color and phenolic composition

The initial concentration of anthocyanin and proanthocyanidin in wine affects the development of SO2-resistant pigments, as well as color and non-color contributing polymeric fractions. However, the effect of extracted monomeric Pinot Noir (Vitis vinifera L. cv.) grape anthocyanins with seed proanthocyanidins are poorly studied. In model ferments, the reaction of purified Vitis vinifera L. cv. Pinot noir monomeric anthocyanins with seed proanthocyanidins extract were investigated at high and low concentrations of each reactant. During wine aging, monomeric anthocyanins decreased whereas SO2-resistant pigments increased. Higher anthocyanin concentrations retained more soluble tannins in model ferments during aging, while those with higher anthocyanin and lower proanthocyanidin concentrations had the highest MCP-tannin concentration in model ferments. HPLC analysis showed that the color contributing polymeric fractions are dependent upon the initial concentration of anthocyanin/proanthocyanidin ratios and more inclined towards high anthocyanin/low proanthocyanidin concentrations. Wine color parameters were measured in the form of L*, a*, b*, C (chroma) and H (hue) values and showed a decrease in hue and chroma in model wines after aging. The color data supported the HPLC findings that the initial anthocyanin/proanthocyanidin ratio was critical for the establishment of a color contributing polymeric fractions and stable deep red color in wines.

Comparison of different maceration and non-maceration treatments for enhancement of phenolic composition, colour intensity, and taste attributes of Malvazija istarska (Vitis vinifera L.) white wines

To investigate the effect of several vinification techniques aimed to enhance wine phenolic profile and sensory quality, maceration treatments of different duration and temperature (pre-fermentative cold one day maceration at 10 °C, seven days maceration at 16 °C, and prolonged post-fermentative 21 day maceration at 16 °C) and non-maceration treatments including tannin addition and late harvest grapes vinification were performed and compared to a standard white grape processing treatment. Produced wines were subjected to the analysis of phenols by high-performance liquid chromatography, colour intensity, and quantitative descriptive and hedonic sensory analysis. The increase in individual phenolic compound concentrations was mostly pronounced in maceration treatment wines, for both phenolic acids and flavan-3-ols, as well as for the sum of phenolic compound concentrations determined by high-performance liquid chromatography that tripled in relation to that determined in control treatment wine. Pre-fermentative cold maceration led to a moderate increase in phenolic compounds content without accentuating bitterness and astringency sensations. Wine phenolic composition and colour intensity were mostly affected by the prolonged post-fermentative 21 day maceration. Vinification of late harvest grapes produced a wine graded with the highest positive score for taste. The obtained distinct wine styles resulting from the application of the investigated practices may lead to a further diversification of white wine market.

Grapevine rootstock genotypes influences berry and wine phenolic composition (&lt;i&gt;Vitis vinifera &lt;/i&gt; L. cv. Pinot noir)

Grapevine rootstocks can affect the nitrogen (N) status of the grafted plant due to discrepancies in their nutrient uptake and their efficiency in the allocation of assimilates. When N becomes a limiting factor, the production of phenolic compounds in grapes is enhanced as a result of a down-regulation of the flavonoid production pathway. However, it is still not fully understood if the impact of rootstocks on fruit and wine composition is mediated by their effect on the vegetative growth and N status of the scion. The main objective of the study was to test if rootstock influence on Pinot noir berry and wine phenolic composition could be related to the N status of the scion. An investigation was carried out on Pinot noir (Vitis vinifera L.) vines grafted onto six rootstocks over three vintages (2012–2014). A micro-scale fermentation technique was used to produce wines from each field replicate. Scions grafted onto SO4, a high vigour rootstock, were characterised by a 15 % higher tannin concentration in berry seed and skin compared to those grafted onto the low vigour Riparia Gloire de Montpellier, while final tannin concentration in wines depended on the rootstock. Anthocyanin concentration was higher in berries of Pinot noir grafted onto R110 compared to 125AA, which was also reflected in the wines. A Multiple Linear Regression analysis suggested that rootstock influence on berry anthocyanins was linked to the N status of scion leaves (higher Leaf NBI_R). Understanding the interaction between the N uptake efficiency of rootstocks and scion berry/wine phenolic composition will help improve the selection of suitable rootstocks that match the desired wine profile.

Is deficit irrigation with saline waters a viable alternative for winegrowers in semiarid areas?

Two of the main challenges of Mediterranean viticulture is low water quality and the risk of increasing concentrations of mineral salts in the root zone. This work was undertaken to study the impact of saline deficit irrigation on grape and wine phenolic composition, as well as on the sensory profile of the wines. The experiment was carried out during three consecutive years (2016-2018) in a commercial vineyard of cv. Monastrell (Vitis vinifera L.) grafted onto 1103P rootstock located in D.O. Jumilla (SE Spain). Three watering regimes were carried out: i) the control (“Control”): the vines were irrigated with water of standard quality, ii) Sulfate treatment (“Sul”): the vines were irrigated with saline water (Na₂SO₄ + MgSO4), and iii) Chloride treatment (“Chl”): the vines were irrigated with saline water (NaCl). The same amount of irrigation water was applied to all the treatments. The water electrical conductivity was 1.8 dS/m for Control and 5 dS/m for the saline treatments (Sul and Chl). Both the Sul and Chl treatments reduced the berry weight in all the study years compared to Control, although this difference was statistically significant in the last year only (p ≤ 0.05). No significant differences (p &gt; 0.05) were observed in the grape quality parameters. However, the saline treatments slightly increased grape total soluble solids (TSS) in two out of the three study years compared to Control. Regarding the phenolic composition, no significant differences (p &gt; 0.05) among treatments were found in grapes and wines. In general, the wines from vines irrigated with saline waters received the best scores by the panel in the sensory profile analysis. The use of saline waters could be employed in the case of water scarcity, as long as the vineyard is planted on a rootstock tolerant to salinity, such as 1103P, and the vineyard soil has a texture that favours leaching.

Impact of oenological processing aids and additives on the genetic traceability of ‘Nebbiolo’ wine produced with withered grapes

‘Nebbiolo’ is a well-known grapevine variety used to produce prestigious monovarietal Italian red wines. Genetic traceability is an important tool used to protect the authenticity of high-quality wines. SNP-based assays are an effective method to reach this aim in wines, but several issues have been reported for the authentication of commercial wines. In this study, the impact of the most common commercial additives and processing aids used in winemaking was analysed in ‘Nebbiolo’ wine using SNP-based traceability. Gelatine and bentonite had the strongest impact on the turbidity, colour and phenolic composition of wines and on residual grapevine DNA. The DNA reduction associated with the use of bentonite and gelatine (>99% compared to the untreated control) caused issues in the SNP-based assay, especially when the DNA concentration was below 0.5 pg/mL of wine. This study contributed to explaining the causes of the reduced varietal identification efficiency in commercial wines.

Discovering the Influence of Microorganisms on Wine Color.

Flavor, composition and quality of wine are influenced by microorganisms present on the grapevine surface which are transferred to the must during vinification. The microbiota is highly variable with a prevalence of non-Saccharomyces yeasts, whereas Saccharomyces cerevisiae is present at low number. For wine production an essential step is the fermentation carried out by different starter cultures of S. cerevisiae alone or in mixed fermentation with non-Saccharomyces species that produce wines with significant differences in chemical composition. During vinification wine color can be influenced by yeasts interacting with anthocyanin. Yeasts can influence wine phenolic composition in different manners: direct interactions—cell wall adsorption or enzyme activities—and/or indirectly—production of primary and secondary metabolites and fermentation products. Some of these characteristics are heritable trait in yeast and/or can be strain dependent. For this reason, the stability, aroma, and color of wines depend on strain/strains used during must fermentation. Saccharomyces cerevisiae or non-Saccharomyces can produce metabolites reacting with anthocyanins and favor the formation of vitisin A and B type pyranoanthocyanins, contributing to color stability. In addition, yeasts affect the intensity and tonality of wine color by the action of β-glycosidase on anthocyanins or anthocyanidase enzymes or by the pigments adsorption on the yeast cell wall. These activities are strain dependent and are characterized by a great inter-species variability. Therefore, they should be considered a target for yeast strain selection and considered during the development of tailored mixed fermentations to improve wine production. In addition, some lactic acid bacteria seem to influence the color of red wines affecting anthocyanins’ profile. In fact, the increase of the pH or the ability to degrade pyruvic acid and acetaldehyde, as well as anthocyanin adsorption by bacterial cells are responsible for color loss during malolactic fermentation. Lactic acid bacteria show different adsorption capacity probably because of the variable composition of the cell walls. The aim of this review is to offer a critical overview of the roles played by wine microorganisms in the definition of intensity and tonality of wines’ color.

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.