Wine Composition Research Articles

Effects of Water Stress on the Phenolic Compounds of ‘Merlot’ Grapes in a Semi-Arid Mediterranean Climate

Of all the abiotic stress types to which plants grown in fields are exposed, the most influential is water stress. It is well accepted that adopting controlled deficit irrigation strategies during the growing season has beneficial effects on the chemical compositions of grapes and red wines. However, there is a discrepancy in the timing, intensity and duration of deficit. This study aimed to evaluate the changes in phenolic composition of ‘merlot’ cultivar grapes when subjected to different levels of water stress in a semi-arid Mediterranean climate. Four treatments with different water stress levels were applied within two phenological intervals (flowering-veraison, veraison-maturity) to 128 grapevines for two consecutive years. The water stress levels for Treatments 1, 2, 3 and 4 were: no-light, light-moderate, moderate-intense and intense for the flowering-veraison and veraison-maturity intervals, respectively. Water stress distinctly affected the phenolic compounds in skin and seeds. The concentrations of flavan-3-ols and total polyphenols were much higher in seeds than in skin, and in both fractions, tannins are the major compounds.

Characterization of odor-active volatile compounds of jambolan [Syzgium cumini (L.) Skeels] wine.

Volatile constituents in jambolan [Syzgium cumini (L.) Skeels] wine were isolated by headspace-solid phase microextraction (HS-SPME) and analyzed by gas chromatography-flame ionization detector (GC-FID), gas chromatography-mass spectrometry (GC-MS), and gas chromatography-olfactometry (GC-O). The composition of the jambolan wine included 52 esters, 20 terpenes, 13 alcohols, 12 acids, 11 aldehydes, 4 ketones, 4 oxides, and 5 miscellaneous compounds. Aroma extract dilution analysis and odor activity units were used for the determination of odor-active compounds. A total of 19 odor-active compounds were found as odor-active volatiles, from which (E)-β-ionone, phenylacetaldehyde, ethyl acetate, ethyl hexanoate, and ethyl benzoate were the most important. The similar results of the GC-O and OAV approaches suggests that HS-SPME-GC-O could be used as a fast and simple tool to quality control of the jambolan wine aroma.

Effect of grape yield and maceration time on phenolic composition of ‘Fetească neagră’ organic wine

The phenolic composition of wine is mostly determined by the accumulation of the phenolic compounds in the grapes, as well as their extraction into wine. To increase their concentration in grapes, yield reduction is usually performed by pruning, while to increase the extraction in wines, the maceration on skins is extended for longer periods of time. The present study focuses on the possibilities to apply both strategies to improve the polyphenol composition of organic red wines of Romanian variety ‘Fetească neagră’, which stands to benefit more from technological interventions than other varieties, which naturally accumulate higher phenol concentrations in the grapes. In the vineyard three experimental pruning variants were made, with 20, 28 and 36 buds/vine, while for wine, maceration was performed for either 8 or 16 days for each grape variant. The phenolic profiles of wines were determined by HPLC methods. The main anthocyanidins, such as malvidin, petunidin, delphinidin, peonidin and cyanidin, as well as the acylated and coumaroylated derivatives of malvidin and peonidin were quantitatively determined. Some other phenolic compounds, of various classes, such as gallic, p-benzoic, p-coumaric and ferulic acid, catechin, epicatechin, myricetin, quercetin and trans-resveratrol were also determined. The quality of the organic ‘Fetească neagră’ wines depended highly on the vintage, but yield reduction and the extension of skin maceration duration were especially beneficial in the less favourable year, when classical technologies lead to less accumulation of sugars, colour and other polyphenols. Concomitant application of both strategies led to the best results, irrespective of the year.

Soil water availability during spring modulates canopy growth and impacts the chemical and sensory composition of Shiraz fruit and wine

Background and Aim Reduced rainfall during vine dormancy and supplementary irrigation during winter or at spring impact on vine growth partitioning. We assess the implications that induced changes on canopy growth due to soil moisture availability in spring have on fruit and wine composition. Methods and Results Irrigation strategies were assessed in a vineyard where winter rainfall was excluded and irrigation was applied during winter or at spring during three seasons. Reduced soil moisture in spring increased canopy porosity from flowering and increased the concentration of phenolic substances in the fruit and wine. Colour, aroma intensity and fruit attributes typical of Barossa Shiraz wines were enhanced under more open canopies. When soil moisture was restored in spring by natural rainfall or by supplementary irrigation, vines developed denser canopies and phenolic substances were reduced in the fruit and wines. Irrigation at spring following a dry winter altered wine style and was associated with some negative attributes. Conclusions Smaller canopies due to reduced water availability at spring improved fruit and wine composition at the expense of yield. Irrigation in spring following a dry winter promoted canopy growth over yield, and impacted negatively on fruit and wine composition. Significance of the Study These results stress the importance that soil water availability in spring has on defining wine style, and establishes a framework for the adoption of irrigation strategies that may maintain regional style in a context of a changing climate. These responses can be expected in regions with a Mediterranean climate experiencing a reduction in winter rainfall.

Copigmentation evidence of phenolic compound: The effect of caffeic and rosmarinic acids addition on the chromatic quality and phenolic composition of Cabernet Sauvignon red wine from the Hexi Corridor region (China)

Although phenolic copigments are rarely colored, they can still influence color expression in red wine copigmentation. Here, prefermentative agents, such as caffeic and rosmarinic acids, were added as copigments during Cabernet Sauvignon red winemaking. The evolution of colors and polyphenols was analyzed by tristimulus colorimetry and high-performance liquid chromatography-tandem mass spectrometry during brewing and aging periods. The results showed that the addition of caffeic and rosmarinic copigments was beneficial to obtain more saturated and vivid hue of wines. The changes in color were correlated with a significant increase in anthocyanins concentration. Moreover, the results demonstrated that the addition of the two phenolic copigments increased the concentration of total phenols and enhanced the copigmentation effect, indicating improved chromatic intensity and color stability of wines. Therefore, the addition of caffeic and rosmarinic acids is a simple and useful enological technique to obtain red wines with high color quality and aging potential.

Effect of Aeration on Yeast Community Structure and Volatile Composition in Uninoculated Chardonnay Wines

Uninoculated wines are regarded as having improved mouthfeel and texture and more complex flavor profiles when compared to wines inoculated with commercial S. cerevisiae strains. Uninoculated fermentation involves a complex microbial succession of yeasts and bacteria during fermentation. Microbial population dynamics are affected by several factors that can ultimately determine if a particular species or strain contributes to wine aroma and flavor. In this work, we have studied the effect of aeration, a common winemaking practice, on the yeast microbiota during uninoculated Chardonnay wine fermentation. The timing of aeration and then aeration intensity were evaluated across two successive vintages. While the timing of aeration significantly impacted fermentation efficiency across oxygen treatments, different levels of aeration intensity only differed when compared to the non-aerated control ferments. Air addition increased the viable cell population size of yeast from the genera Hanseniaspora, Lachancea, Metschnikowia and Torulaspora in both vintages. While in 2019, a high relative abundance was found for Hanseniaspora species in aerated ferments, in 2020, T. delbrueckii was visibly more abundant than other species in response to aeration. Accompanying the observed differences in yeast community structure, the chemical profile of the finished wines was also different across the various aeration treatments. However, excessive aeration resulted in elevated concentrations of ethyl acetate and acetic acid, which would likely have a detrimental effect on wine quality. This work demonstrates the role of aeration in shaping yeast population dynamics and modulating a volatile profile in uninoculated wines, and highlights the need for careful air addition to avoid a negative sensory impact on wine flavor and aroma.

Toward Understanding the Mechanism of Wine Oxidation

The electronic configuration of oxygen (O₂) does not allow it to react directly with wine reductants such as polyphenols. It relies on the catalytic intervention of iron (Fe), which redox cycles between its ferrous (Fe(II)) and ferric (Fe(III)) states. O₂ oxidizes Fe(II) to Fe(III), and Fe(III) then oxidizes polyphenols. Low concentrations of copper accelerate oxidation, and nucleophiles, especially sulfite, promote polyphenol oxidation. In wine that is protected from air, Fe exists mainly as Fe(II), but the Fe(III):Fe(II) concentration ratio increases immediately on air exposure, stabilizing at varying speeds and values. The oxidation of Fe(II) in air-saturated model wine and the reduction of Fe(III) by a catechol under nitrogen in model wine were examined separately to better understand the oxidative process. The Fe(III) produced when Fe(II) reacted with O₂ slows the reaction. As in wine, it was important to include sulfite to remove the intermediate hydrogen peroxide, which also oxidizes Fe(II). The reaction was pseudosecond-order in Fe(II), indicating that the transfer of both electrons to O₂ is rate determining. Similarly, when Fe(III) was reduced by the catechol, the Fe(II) produced inhibited the reaction, which overall followed a pseudosecond-order rate law in Fe(III). The rate of Fe(II) oxidation was slower than the rate of Fe(III) reduction, but when the reactions occurred together, as in wine oxidation, Fe(III) and Fe(II) concentrations equilibrated such that their rates equalized. Under the conditions studied, this occurred at 32% Fe(III). This equilibrium was attained quickly, as is the case in red wine. These findings on the oxidative process should help explain the relationships between wine composition, redox state, and Fe(III):Fe(II) concentration ratios.

Delaying Budbreak to Reduce Freeze Damage: Seasonal Vine Performance and Wine Composition in Two Vitis vinifera Cultivars

Spring freeze events pose a threat to vineyard productivity worldwide. We compared two methods to delay grapevine budbreak for freeze avoidance and evaluated their effects on phenology, yield components, fruit composition, and postharvest parameters, including wine chemistry, carbohydrate storage, and bud freeze tolerance. The two methods to delay budbreak were a vegetable oil-based adjuvant (Amigo) applied to dormant buds at 8% and 10% (v/v) and late pruning applied when apical buds reached approximately Eichhorn-Lorenz stage 7. Treatments were applied in 2018 and 2019 on two <i>Vitis vinifera</i> cultivars, Lemberger and Riesling, and compared to a control treatment with no delayed budbreak strategy. Amigo and late pruning delayed budbreak compared to control vines in both years and cultivars. The delay in budbreak varied from three to six days for Amigo 8%, five to eight days for Amigo 10%, and 10 to 11 days later for late pruning. In 2019, there was a freezing event near budbreak. Compared to control vines, late-pruned Lemberger vines had less shoot damage when measured during the growing season and greater yield at harvest. Delayed budbreak treatments did not influence wine chemistry either year or consistently affect carbohydrate storage or bud freeze tolerance in the following dormant season. However, in Riesling, late pruning reduced cluster and berry weight by up to 34 and 22%, respectively, compared to control vines. Furthermore, Amigo 10% may decrease bud survival when applied to Riesling vines. In general, late pruning delayed budbreak more effectively and mitigated freeze damage better than Amigo application without negatively affecting vine health or wine composition; however, the cultivar-dependent effect of late pruning on cluster weight is a consideration prior to adoption.

Effects of Flower Cluster Tip Removal on Phenolics and Antioxidant Activity of Grape Berries and Wines

Insufficient sunlight during veraison to maturity of winegrapes is a primary factor that inhibits production of phenolic compounds. In this study, a novel thinning technique called cluster tip removal (CTR) was applied to inflorescences of <i>Vitis vinifera</i> L. Marselan grapes, and the berry composition, phenolic profiles, and antioxidant activities of berry skins and wines were determined. CTR of inflorescences reduced cluster compactness, lowered titratable acidity, and increased total soluble solids in berries. CTR also increased concentrations of total phenolics, anthocyanins, tannins, and flavonoids in the pedicel end of berry skins and enhanced concentrations of 12 phenolic compounds. It also increased the concentrations of total flavanols and anthocyanins in wines. CTR berries and wines also had increased antioxidant capacities. Finally, expression of phenolic-related genes was upregulated in the skin of CTR berries.

Impact of Commercial Yeasts on Phenolic Profile of Plavac Mali Wines from Croatia

Wine quality is influenced by the presence of over 500 different chemical compounds, with polyphenols having a crucial role in color intensity and tonality, astringency, mouthfeel, and overall impression formation, especially in red wine production. Their concentrations in wine can vary notably depending on the grape variety, the temperature and the length of maceration process, aging duration, and yeast selection. Therefore, in this work, the main goal was to determine the influence of five commercially available Saccharomyces yeasts provided from Lallemand, France and AEB, Italy, on the phenolic compound composition and chromatic parameters of Plavac mali wines produced from the grapes from coastal Dalmatia, grown at two different micro-locations. The achieved results pointed out the marked difference in individual polyphenol compound adsorption between tested yeasts. Fermol Super 16 was the one with the lowest and Lalvin D21 the strongest adsorption ability, regardless of vine growing location. These differences can be explained by the content of some anthocyanins (delphinidin and petunidin-3-O-glucoside) and gallic acid, and some flavan-3-ols. Tested strains also influenced wine color intensity, pointing out the possibility of modulating the style of a Plavac mali by the use of commercial yeasts.

Differences in fruit and wine composition (Vitis viniferaL. ‘Pinot Noir’) detected through non-invasive fluorescence sensor technology

ISHS International Symposium on Precision Management of Orchards and Vineyards Differences in fruit and wine composition (Vitis vinifera L. 'Pinot Noir') detected through non-invasive fluorescence sensor technology

Wine composition of Merlot and Cabernet Sauvignon vine clones under the environmental conditions of Serra Gaúcha, Brazil

This study aimed to evaluate the wine composition from vine clones of Merlot (181, 346, 347, 348) and Cabernet Sauvignon (R5, 18A, 163, 338, 341). The grapes were harvested between 2010 and 2012, then on the same day, taken to the winery facility for winemaking. After crushing and destemming the grapes, the musts were transferred to glass containers, where the alcoholic and later malolactic fermentations occurred. Next, the wines were bottled and analyzed, where the classical variables were determined by physicochemical methods, volatile compounds by gas chromatography, and minerals by atomic absorption spectrophotometry. Data were submitted to ANOVA, Tukey test, correlation analysis, and Principal Component Analysis. The clone effect was significant for some variables; however, year and varietal group exerted greater effects. The Merlot group generally had higher values of ethanol, absorbance at 520 nm, color intensity, total polyphenols index, and methanol. On the other hand, the Cabernet Sauvignon group presented higher pH, ashes, alkalinity of ashes, hue, and potassium. Therefore, the three-year average data demonstrate that the evaluated Merlot and Cabernet Sauvignon clones are suitable to produce quality wines in the region, especially Merlot 181, 346, and 348 and Cabernet Sauvignon 18A and 163.

Non-Saccharomyces yeasts as bioprotection in the composition of red wine and in the reduction of sulfur dioxide

Non-Saccharomyces yeasts have been used for many years due to their technological potential, particularly as a “booster” of wine fruity aroma in mixed fermentations with Saccharomyces cerevisiae. Recently, a new application has emerged, bioprotection, which consists in colonizing the environment in the context of sulfite reduction in wines. The chemical and sensory impact of non-Saccharomyces yeast according to different modes of application in a context of fermentation without addition of SO2 was evaluated through trial with Merlot N. (Vitis vinifera L.). An effective niche occupation by non-Saccharomyces yeasts was highlighted during the prefermentary stages by Quantitative-PCR and MALDI-TOF MS identification. Chemical analysis (GC-MS and GC MS/MS) of finish wine showed the significant impact of the dose applications, with bioprotection characterized by linear esters and sequential application by acetates of higher alcohol contents. Moreover, a separation according to the species used in bioprotection was revealed. Finally, using a panel trained, the sensory analysis confirmed that the use of non-Saccharomyces yeast was a fruity booster in sequential inoculation and, to a less extent, when used as bioprotection. This study shows for the first time that the use of non-Saccharomyces yeast as a bioprotection has a significant impact on the aromatic profile of wines.

Effect of Microwave Maceration and SO2 Free Vinification on Volatile Composition of Red Wines.

This study evaluates the effect of microwave treatment in grape maceration at laboratory scale on the content of free and glycosidically bound varietal compounds of must and wines and on the overall aroma of wines produced with and without SO2. The volatile compounds were extracted by solid phase extraction and analyzed by gas chromatography–mass spectrometry, carrying out a sensory evaluation of wines by quantitative descriptive analysis. Microwave treatment significantly increased the free and bound fraction of most varietal compounds in the must. Wines from microwave maceration showed faster fermentation kinetics and shorter lag phase, resulting in an increase in some volatile compounds of sensory relevance. The absence of SO2 caused a decrease in concentration of some volatile compounds, mainly fatty acids and esters. The sensory assessment of wines from microwave treatment was higher than the control wine, especially in wines without SO2, which had higher scores in the “red berry” and “floral” odor attributes and a more intense aroma. This indicates that the pre-fermentative treatment of grapes with microwaves could be used to increase the wine aroma and to reduce the occurrence of SO2.

Impact of oak wood modalities on the (non)-volatile composition and sensory attributes of red wines

During fermentation or ageing of wines, oak wood is commonly used in form of barrels, casks or derived oak products (chips, winewoods, tankstaves, among others). It is well known that aroma, structure, astringency, bitterness, aromatic persistence and colour may change as a result of wine‒wood contact. A full-scale experimentation was performed under different oak ageing conditions in order to evaluate colour, phenolic, aromatic and sensory differences among final red wines (9‒months ageing). Oenological parameters and wine colour were not impacted by ageing modality. At the end of ageing, no differences were found in total phenolic and tannin contents. Regardless of the ageing modality, total content and profile of fruity volatiles were globally maintained with regard to control (≥ 86 %). In contrast, the higher the surface of wine‒wood contact per unit of wine volume, the greater the extraction of woody aromas. Thus, barrels led to wines with the highest level of woody aromas (515‒864 µg/L), followed by cask modalities (430‒470 µg/L). From a sensory point of view, descriptors highlighting the woody character of wine (vanilla, spicy) were enhanced in all oak‒aged wines when compared to control. However, our results indicate that a masking effect of fruity aroma by oak wood did not occur, since all modalities were perceived as fruity as the control. Thus, each oak ageing modality may lead to wines with a different woody character, without no impact on fruity perception, allowing wineries to achieve the targeted aromatic profile, good structure and just the right balance between fruity and woody aromas.

Influence of pre-fermentative addition of aqueous solution tannins extracted from oak wood (Quercus petraea) on the composition of Grillo wines

In this research, the chemical characterization of fixed and volatile compounds of two different tannins in aqueous solution (Pratiko® L-Harvest and L-Fruit) extracted from oak wood, has been studied. The influence of the above tannins, at different concentrations, on the alcoholic fermentation kinetics and on the composition and sensorial characteristics of a white wine were then evaluated. The wines added tannins in aqueous solution compared to control wines showed significant differences in fixed compounds (colloids, polyphenols and ellagitannins) and volatile compounds (phenolic aldehydes, volatile phenols, furanic and piranic compounds). The differences of aqueous solution tannins extracted from oak wood were partly due to the drying/maturing and roasting methods used in barrel production. Alcoholic fermentation was partially facilitated by the addition of tannins in aqueous solution. The wines obtained showed a higher content of ethyl esters of medium-chain fatty acids (from 22 to 31%) and, in some cases, higher acetate alcohols (from 15 to 28%), relevant to the olfactory sensations provided to the wines. The tannins added to the must before fermentation also made it possible to obtain an additional supply of polyphenols (from 25 to 85%) able to induce more complex sensory profiles in the wines, with increased persistent taste notes.

Regionality in Australian Shiraz: compositional and climate measures that relate to key sensory attributes

Background and Aims Regional characters or the ‘terroir’ aspects of Shiraz are not well understood. This study aimed to characterise the chemical composition of wines from sites within six important Australian regions, and the climate profiles of the sites, and to determine how they relate to sensory differences. Methods and Results For 22 commercially produced wines 70 chemical measures and 17 site- and season-specific climate indices were determined. Wines with stalky/cooked vegetal sensory properties had a higher concentration of cinnamate esters and dimethylsulfide, which through multivariate analyses was related to later budburst and time of harvest. Wines with a higher concentration of monoterpenes were associated with floral aroma. High radiation measures were linked to higher tannin, colour density, norisoprenoid compounds and phenylethyl acetate and to stronger dark fruit/dried fruit and tannin/colour attributes. High rainfall indices were generally related to low sensory attribute ratings and compositional measures. From cluster analysis of compositional data, wines were well grouped by region of origin. Conclusions Distinctive chemical fingerprints exist for the regions studied, and their climatic profiles were strongly associated with wine composition, with key compounds influencing sensory differences. Significance of the Study The approach of applying multiple site- and season-specific climate measures and relating these to chemical composition and the characteristic sensory attributes of regional Australian Shiraz wines can help producers better understand and influence the effect of place on their wines.

Differentiation of Wines Obtained in the Region of Dealurile Moldovei Vineyard Using Multielement Composition - Comparison with Vineyard Soil

The present study is focused on the determination of mineral composition of international red wines (Merlot, Cabernet Sauvignon), white wines (Sauvignon blanc, Aligoté, Muscat Ottonel, Italian Riesling) and native red wines (Feteasca neagră, Burgund mare, Băbeasca neagră), white wines (Feteasca regală, Fetească albă, Băbeasca gri, Șarba) produced in the Dealu Bujorului vineyard between 2014-2018, using Inductively Coupled Plasma Mass-Spectrometry (ICP-MS), and comparison of mineral composition of the soil. The high level of Ca, K, Na, Mg, P and Fe was observed in analyzed wine samples, the concentration of Na, Cu, As, Cd, Zn and Pb metals in analyzed wine samples were under Maximal Permissible Limit. The average concentrations of elements in the soil decrease in the following order: K, Na, Ca, Cu, Fe, P, Mg, Li, Co, Mn, Zn, Pb, Cr, As, U, Cd and Hg. Cu concentration in the topsoil of the Dealu Bujorului vineyard exceeds the maximum allowed limit (20 mg/kg Cu).

Characterization of Tempranillo negro (VN21), a high phenolic content grapevine Tempranillo clone, through UHPLC-QqQ-MS/MS polyphenol profiling

Grapevine cultivar and clone genotype is an important factor in the phenolic composition of wine. In this study, a new intense dark black berry color variant of Tempranillo, known as Tempranillo negro or VN21, is described. A targeted chromatographic approach based on UHPLC-QqQ-MS/MS was used to study the anthocyanins and non-colored phenols of the grape berry (skin and seeds) and wine. RJ43, one of the most cultivated clones in D.O.Ca. Rioja (Spain), was analyzed for comparison. Results suggest that the unique color of the grape skin in Tempranillo negro could be explained by higher concentrations of peonidin and cyanidin derivatives. This genotype accumulated anthocyanins in the seeds. Those differences in the berry were enhanced in the VN21 wines, which displayed notably higher concentrations of anthocyanins, and significantly increased contents of proanthocyanidins and stilbenes. This study exemplifies the application of phenol chromatographic analyses of spontaneous somatic variants to grapevine clonal selection.

The impact of mycorrhiza on chemical composition of Portugieser wine

Cilj ovog istraživanja bio je utvrditi kako primjena živog mikoriznog cjepiva na korijen vinove loze utječe na kemijski sastav vina ´Portugizac´. Pokus je postavljen u jesen 2016. godine na 3 lokacije na području podregije Plešivica, kada je provedena i aplikacija cjepiva naziva „Mykoflor“ tvrtke Bio-budućnost d.o.o. Cjepivo je aplicirano na 100 trsova sorte ´Portugizac´, pri čemu je isti broj netretiranih trsova poslužio kao kontrola. Analiza kemijskog sastava, kao i senzorno ocjenjivanje vina provedeni su nakon berbe 2018. godine. Rezultati su pokazali pozitivan utjecaj mikorize na kemijski sastav vina u vidu povećanja koncentracije ukupne kiselosti, pojedinačnih organskih kiselina, pepela te smanjenja pH vrijednosti vina. Aplikacija mikoriznog cjepiva pozitivno je utjecala i na polifenolni sastav te na senzornu ocjenu vina.