Chemical Composition Of Wines Research Articles

Идентификация кристаллов тартратных солей в составе осадка вин

Crystalline sediment of potassium hydrotartrate and calcium tartrate in wines is a major problem of wine industry. Reliable identification of crystals can establish the cause of their formation and facilitate appropriate technological solutions. The research objective was to study the morphological features of potassium and calcium salts of tartaric acid via microscopy.
 The study featured natural crystal sediments that developed in 105 samples of white and red wines over six months after the end of fermentation, as well as when crystallization was provoked by freezing. The microscopic examination involved a Micmed-5 optical microscope and a PHENOMproX scanning electron microscope. Identification of cations in the composition of crystals followed the method of energy-dispersive spectroscopy, as well as the method of quality reaction with sulfate-anion in acidic medium.
 Co-precipitation of colloidal substances was typical of potassium hydrotartrate. It violated the crystal lattice construction and determined the wine color, polymorphism (truncated ellipsoid → lanceolar → rhomboid → geometrically irregular shapes), surface roughness, and optical opacity. The expressiveness increased with the crystal growth (3–350 μm). Calcium tartrate demonstrated no evolutionary changes; it was morphologically uniform, colorless, and transparent. Its crystals had smooth faces and clear edges, regardless of their size (1–150 μm) and the chemical composition of wine.
 The research systemized the morphological features of tartrate crystals formed in wines. The obtained results are important for the technochemical control in the process of destabilization diagnosis. The data can be recommended for further studies in applied research laboratories and institutes.

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.

Vine Age Affects Vine Performance, Grape and Wine Chemical and Sensory Composition of cv. Zinfandel from California

Mendelian randomisation is a technique for assessing causal associations in observational data. Genetic variants associated with the risk factor of interest are regarded in a similar way to random assignment in a clinical trial. The difference in the risk factor due to the genetic variation, however, is materially distinct from the change due to any proposed therapeutic intervention and so might affect the outcome differently. Consequently, it can be misleading to generalise the magnitude of a Mendelian randomisation estimate to the effect of a potential intervention on the risk factor in practice. Awareness of the limitations of such estimates is important for the use of Mendelian randomisation in target based drug development

Use of Microwave Maceration in Red Winemaking: Effect on Fermentation and Chemical Composition of Red Wines.

The objective of this study was to evaluate the effect of microwave treatment of crushed grapes on the yeast population of the must and on the development of alcoholic fermentation, as well as on the extraction of different compounds from the grapes such as polysaccharides and amino acids that can affect the organoleptic quality and stability of the wine. This study demonstrated for the first time the effect of the microwave treatment of grapes on native yeast species and their diversity, producing an increase in fermentation kinetics and a decrease in the lag phase. The microwave treatment produced a positive effect on the extraction of amino acids and polysaccharides from the grapes, resulting in significantly higher amounts of the main amino acids of the must and some major volatile compounds in the treated samples. The polysaccharides most affected by the microwave treatment were the PRAGs, the main polysaccharides liberated from grapes during the maceration.

Microwave-assisted maceration and stems addition in Bonarda grapes: Effects on wine chemical composition over two vintages

Bonarda, the second red grape variety in Argentina, produces high yields per hectare generating, in several cases, low quality wines. Microwave-assisted extraction (MW) is a novel extraction technique for winemaking, widely applied in other foods. Stems addition (S) during vinification can be a sustainable technology for phenolic and aroma contribution without additional cost. Therefore, this study aimed to evaluate the combined effect of MW application with stem additions in different conditions, before fermentation, on the chemical composition of Bonarda wines. During two consecutive vintages (2018 and 2019), the experimental design consisted of ten treatments (two factors) by triplicate. Two maceration strategies (Factor 1) were applied [control (C), and microwaved-assisted extraction after grape crushing (MW; 2450 MHz, 7600 W, 45–50 °C)], combined with five stem-contact conditions (Factor 2) [control without stems (WS), 50% stems addition (S50), 50% stems addition + MW of the stems (S50MW; 2450 MHz, 7600 W, 60 °C), 100% stems addition (S100), 100% stems addition + MW (S100MW)]. Wines were analyzed for basic chemistry, phenolic composition and color parameters, polysaccharides, and aroma profiles. The 2018 wines showed higher pH and lower volatile acidity with stem additions and MW application in both matrices (grapes and stems). Stem additions increased tannin content by >55% (S100) and by >25% for the other treatments; while MW, mostly in the 2018 season, consistently improved phenolic extraction and polymeric pigments formation, enhancing wine color (greater saturation) and intensifying violet hue. The behavior observed in 2019 was similar, with a more marked effect of MW on wine color (C*ab and polymeric pigments). Likewise, combined strategies increased polysaccharides extraction and modified the volatile profile of wines. The reported results are promising and are considered the first advance in the knowledge of the impact of the proposed combined strategies on the chemical composition of red wines.

1H NMR and UPLC-HRMS-based metabolomic approach for evaluation of the grape maturity and maceration time of Touriga Nacional wines and their correlation with the chemical stability

Touriga Nacional is a well-adapted Portuguese grape variety in São Francisco River Valley (northeastern Brazil). Nevertheless, it has only been indicated to short-term consumption because of the lack of chemical stability, which is attributed to low grape acidity and incomplete phenolic maturity. Therefore, we used Ultra-Performance Liquid Chromatography coupled High-resolution Mass Spectrometry, Nuclear Magnetic Resonance and chemometrics (PCA and PLS-DA) to evaluate the grape maturity and maceration time on chemical composition of wines from two harvest seasons. Moreover, we investigated how these experimental factors could affect their chemical stability. Grapes maturity showed to be the main effect. Overall, phenolic acids and short-chain organic acids were found to be at higher levels in wines produced with unripe grapes from February and shorter maceration time (p < 0.05). Proanthocyanidins and other flavonoids were increased in wines macerated for longer time using overripe grapes harvested in July. Furthermore, stable wines were made from overripe grapes, which contained more galacturonic acid.

Passports of wines produced from the several grape varieties from western Georgia

The monograph is dedicated to the study of chemical composition of several wines produced from the … grape varieties in western Georgia using modern analytical methods. The results are used to create passports for these wines that would indicate correlation between the chemical composition of the wine, its varietal origin and geographical origin.Monography will be interesting for the specialists from the fields of agriculture and food technology such as experts, students, farmers, and manufacturers.The above project was fulfilled by financial support of the Georgian National Science Foundation (Grant AP/96/13 and 216816). Any idea in this publication is possessed by the authors and may not represent the opinion of the Georgian National Science Foundation.

Effect of Yeast Assimilable Nitrogen Content on Fermentation Kinetics, Wine Chemical Composition and Sensory Character in the Production of Assyrtiko Wines

Two wild-type Saccharomyces cerevisiae yeast strains (Sa and Sb) were tested for white wine production using Assyrtiko grape of Santorini. A third commercial Saccharomyces strain was also studied for comparison reasons. Two concentrations of yeast extract and diammonium phosphate (DAP) were added to the must (150 and 250 mg/L) in order to evaluate the effect of nitrogen content on the final wine quality. Analytical methods (HPLC, GC-MS) and sensory analysis were employed to assess the quality of the wines. Fermentation kinetics were monitored throughout the experiment. By the second day of fermentation, all strains showed an approximate consumption of 70% of amino acids. Differences among strains were observed regarding inorganic nitrogen requirements. Sb strain resulted in higher concentrations of higher alcohols (1.9-fold) and ketones (5.6-fold) and lower concentrations of esters (1.2-fold) compared to the control, while Sa strain resulted in higher content of fatty acids (2.1-fold). Both indigenous strains scored better results in aroma quality, body and acidity compared to control. The overall evaluation of the data highlights the great potential of the indigenous S. cerevisiae strains as fermentation starters providing promising results in the sector of terroir wines.

Phenolic compounds in the autochthonic grape varieties of west Georgia

The above project was fulfilled by financial support of the Georgian National Science Foundation (Grant AP/96/13 and 216816). Any idea in this publication is possessed by the authors and may not represent the opinion of the Georgian National Science Foundation.The monograph is dedicated to the study of chemical composition of several wines produced from the grape varieties in western Georgia using modern analytical methods. The results are used to establish a correlation between chemical composition of the wine, its varietal origin and soil/climate factors.Monography will be interesting for the specialists from the fields of agriculture and food technology such as experts, students, farmers, and manufacturers.

Mechanical Pruning and Soil Organic Amending in Two Terroirs. Effects on Wine Chemical Composition and Sensory Profile

The knowledge about the interaction between mechanical pruning and soil organic amending is still scarce. This study aimed to examine the effects of the interaction between these two practices on wine quality. Syrah grapes from two trial fields in Portugal subjected to two different pruning systems (mechanical pruning; hand spur pruning) and five different organic amendment treatments (control, biochar, municipal solid waste compost, cattle manure, and sewage sludge) were harvested and vinified for four years. Mechanical pruning significantly reduced wine alcoholic strength, pH, and total anthocyanins. Mechanical pruning and organic amendments, tendentially reduced wine total phenols and tannin power, known as an “estimation of the astringency potential of the wines”. Tasters found low but significant differences in global appreciation with the pruning system. Sludge tended to reduce wine global appreciation more than municipal solid waste compost and cattle manure, while biochar had no effect on tasters’ preference when compared to the control. There was strong relation between yield and tasters’ preference only above 6 kg/vine and 8 kg/vine depending on the terroir. Mechanical pruning tendentially has significant effects on wine quality when yield raises above a certain level. Thus, with this pruning system, the choice of the organic amendment and its amount must be done considering the destiny of the produced grapes. To the best of our knowledge, effects of the interaction of mechanical pruning with soil organic amending on wine quality are a novelty.

Manipulating Nitrogen and Water Resources for Improved Cool Climate Vine to Wine Quality

Low yeast assimilable nitrogen (YAN) concentrations (&lt;140 mg/N/L) can produce wines with inferior aroma and flavor, regardless of supplemental nitrogen (N) additions in the winery. The impact of doubling commercial field N and irrigation rates was explored in <i>Vitis vinifera</i> L. cv. Chardonnay and Pinot noir over three growing seasons (2016 to 2019) in Southern Tasmania, Australia, to improve YAN concentrations and observe the concurrent influence on vine canopy, yield, and grape and wine composition. Six combinations of irrigation and N rates were applied to 20 vines for each treatment combination and replicated across both cultivars. The treatments included the standard irrigation rate (~530 L/vine/year) / control N (0 kg/N/ha/year) rate, standard irrigation / standard commercial N rate (~18 kg/N/ha/year), standard irrigation / double commercial N rate (~36 kg/N/ha/year), double irrigation rate (~1060 L/vine/year) / control N, double irrigation / standard N, and double irrigation / double N. Analysis of variance was used to determine main treatment effects and treatment interactions of the measured variables for a subset of the vine population in each growing season. Increasing N rate improved YAN concentrations in both cultivars in two of three growing seasons, with the double N rate associated with increasing YAN to acceptable (&gt;140 mg/N/L) levels. Irrigation had no impact on YAN concentrations. Treatment influences on vine vegetative growth, yield, and grape and wine composition were marginal, inconsistent, and largely influenced by climatic conditions. Cool-climate grapegrowers would benefit from applying more N in the vineyard around veraison to improve YAN without stimulating vigor or reducing the quality of grape and wine chemical composition. Increasing irrigation rates may be advantageous in seasons with high crop load; however, current commercial irrigation rates are considered adequate.

1H-NMR Metabolomics as a Tool for Winemaking Monitoring.

The chemical composition of wine is known to be influenced by multiple factors including some viticulture practices and winemaking processes. 1H-NMR metabolomics has been successfully applied to the study of wine authenticity. In the present study, 1H-NMR metabolomics in combination with multivariate analysis was applied to investigate the effects of grape maturity and enzyme and fining treatments on Cabernet Sauvignon wines. A total of forty wine metabolites were quantified. Three different stages of maturity were studied (under-maturity, maturity and over-maturity). Enzyme treatments were carried out using two pectolytic enzymes (E1 and E2). Finally, two proteinaceous fining treatments were compared (vegetable protein, fining F1; pea protein and PVPP, fining F2). The results show a clear difference between the three stages of maturity, with an impact on different classes of metabolites including amino acids, organic acids, sugars, phenolic compounds, alcohols and esters. A clear separation between enzymes E1 and E2 was observed. Both fining agents had a significant effect on metabolite concentrations. The results demonstrate that 1H-NMR metabolomics provides a fast and robust approach to study the effect of winemaking processes on wine metabolites. These results support the interest to pursue the development of 1H-NMR metabolomics to investigate the effects of winemaking on wine quality.

The effect of grape juice dilution and complex nutrient addition on oenological fermentation and wine chemical composition

The impact of water addition and complex nutrient addition to grape juice in laboratory scale winemaking, on both alcoholic and malolactic fermentation duration and outcome has been examined using commercial wine yeasts, Lalvin EC1118™ and Lalvin R2™and malolactic bacteria Lalvin VP41™. As expected, dilution with water did not impede fermentation, instead resulted in shortened duration, or in the case of malolactic fermentation enabled completion in these conditions. Addition of complex organic nutrient further shortened alcoholic fermentation by Lalvin R2™ and in some conditions also reduced the duration of malolactic fermentation. In general, compounds contributing to wine aroma and flavour were present at lower concentrations at the end of fermentation where juices were diluted and the addition of organic complex nutrient also influenced the concentration of some compounds in wine. These findings are significant to commercial winemaking, highlighting that winemakers should consider potential impacts of juice dilution on processing efficiencies along with wine flavour and aroma.

Exploiting Flow-Based Separation Techniques for Sample Handling in Wine Analysis

Wine is a fermented product consumed in a large scale all over the world that therefore has a large impact both economic and food safety terms. The analytical control of the final product is thus of high importance; it is not a simple task given that the chemical composition of wine is very variable and complex. Consequently, there is always the need for some sample pre-treatment prior to analysis. Flow-based analyses are known for their efficiency in sample manipulation and can be easily coupled to other techniques, such as separation techniques, namely membrane-based or extraction procedures. This possibility is an important step when dealing with complex matrices, such as wine samples. This review presents the state of the art of the methodologies that were developed using flow-based systems coupled to separation devices applied to wine analysis, namely membrane-based, solid, and liquid phase extraction and low pressure chromatography separations.

Perspectives on Wines of Provenance: Sensory Typicality, Quality, and Authenticity

Wine is revered throughout the world and comes in many varieties and styles. Factors influencing wine chemical composition and sensory properties are complex but can be related to product origin. Wine provenance also invokes notions of typicality and quality that underpin the reputation of wines and their regions. This perspective outlines current aspects related to sensory typicality, quality control, and authenticity for wines from delimited regions. It covers the influence of terroir, links between typicality and quality, control of quality through sensory assessment, the relationship with authenticity, and rapid methods for classification of wines according to origin, variety, or vintage.

An assessment of voltammetry on disposable screen printed electrodes to predict wine chemical composition and oxygen consumption rates

The present work aimed at determining the applicability of linear sweep voltammetry coupled to disposable carbon paste electrodes to predict chemical composition and wine oxygen consumption rates (OCR) by PLS-modeling of the voltammetric signal. Voltammetric signals were acquired in a set of 16 red commercial wines. Samples were extensively characterized including SO2, antioxidant indexes, metals and polyphenols measured by HPLC. Wine OCRs were calculated by measuring oxygen consumption under controlled oxidation conditions. PLS-Regression models were calculated to predict chemical variables and wine OCRs from first order difference voltammogram curves.A significant number of fully validated models predicting chemical variables from voltammetric signals were obtained. Interestingly, monomeric and polymerized anthocyanins can be differently predicted from the first and second wave of the first derivative of voltammograms, respectively. This fast, cheap and easy-to-use approach presents an important potential to be used in wineries for rapid wine chemical characterization.

Modulating a wine profileModulating a wine profile via an innovative use of vine-shoots

The chemical composition of vine-shoots is characterised by oenological compounds with high added value, which could contribute to the sensory profile of wines. In this study, toasted vine-shoots from two varieties were used in two different formats, granules and chips, and added to wine at different winemaking stages. The results show that oenological additives in the form of vine-shoots can modulate the chemical composition of wines, and therefore their quality, by enhancing their varietal and woody aromas; thus connecting viticulture and oenology and creating a new concept: circular viticulture.

Influence of inclusion of grapevine leaves, rachis and peduncles during fermentation on the flavour and volatile composition ofVitis viniferacv. Shiraz wine

Background and Aims The presence of matter other than grapes (MOG) is common in the winemaking process when sorting equipment is not utilised. Experimental wines were made to examine the effect of MOG on the sensory profile and chemical composition of wine. Methods and Results A Shiraz wine made without MOG was compared to fermentations with grape leaves, grape stalks (rachis) and peduncles (the stalk connecting the bunch to the vine) added at amounts at or slightly above those found in a commercial harvest bin. Fifty-one volatile aroma compounds were quantified in the wines, and sensory descriptive analysis was applied. The wine made with leaves added was rated by the sensory panel similar to the Control and was significantly higher only in positive aromas such as ‘confectionery’ and ‘red fruit’ likely due to a higher concentration of hexanol and (Z)-3-hexen-1-ol. The addition of peduncles slightly enhanced ‘green’ aroma and flavour. The rachis treatment was high in ‘green capsicum/green stalks’ attributes, as well as astringency, and was high in methoxypyrazines. Conclusions The inclusion of different types of MOG during fermentation can alter the sensory profile and chemical composition of Shiraz wines in varying ways, including extraction of methoxypyrazines from the rachis, resulting in notable ‘green’ attributes. Significance of the Study The inclusion of MOG is unavoidable in common winemaking practices, especially with the use of mechanical harvesting. Determining the influence of MOG on the volatile composition of the finished wine is an important step in manipulating wine style.

Aeration ofVitis viniferaShiraz fermentation and its effect on wine chemical composition and sensory attributes

Background and Aims Aeration during fermentation of red wines has the potential to enhance positive red fruit attributes and suppress less desirable reductive characteristics. The implementation of aeration in commercial winemaking, however, is impeded by the lack of a clear understanding of both the major benefits of its use and the nature of the aeration regimes required to modify the finished product. This work aimed to evaluate the impact of different modes of aeration, varying in their timing, duration and intensity, on fermentation duration, chemical composition and sensory properties of Shiraz wine. Methods and Results Forty-eight pilot-scale fermentations (450 kg) were treated with different aeration modalities and compared to non-aerated fermentations across four vintages. This work demonstrated the reproducible effects of aeration, resulting in an enhancement of fruit-related attributes, decreases in colour intensity and a lowering of astringent mouthfeel and bitterness. The development of attributes describing possible oxidation or undesirable volatility were not observed in this work. These effects on wine sensory attributes were correlated with an increase in the concentration of relevant short and branched-chain esters and acetates, and a decrease in the concentration of phenolic substances. No enhancement of fermentation performance was observed in any of the trials. Overall, this work revealed the robustness of red wine fermentations to aeration. Conclusions This work provides strong evidence that aeration does not alter the duration of either alcoholic or malolactic fermentation of red musts. Although there was no impact on fermentation performance, aeration did result in the production of wines with increased red fruit characters, and decreased astringency and reductive off-odours. Significance of the Study This work demonstrates aeration to be a useful oenological tool for the production of red wine and indicates that stylistic impact, rather than fermentation performance, is likely to be more pertinent to the adoption of red wine aeration.

Defining wine typicity: sensory characterisation and consumer perspectives

Wine encapsulates the expression of multiple inputs – from the vineyard location and environment to viticultural and winemaking practices – collectively known as terroir. Each of these inputs influence a wine's chemical composition and sensory traits, which vary depending on cultivar as well as provenance. These aspects underpin the overall concept of wine typicity, an important notion that enables wine from a delimited geographical area to be differentiated and recognisable in national and international wine markets. Indeed, consumers are increasingly more aware of the significance of regionality and may use this to influence their purchasing decisions. Understanding which sensory attributes represent regional typicity and how these are best conveyed to consumers is therefore important for the prosperity and reputation of producers. As reviewed herein, the sensory typicity of wine can be identified using different types of testing methods, with the most effective being a combination of approaches, such as sorting task in combination with descriptive sensory analysis. Consumer perceptions of regionality and wine typicity are then examined to provide insight into their behaviours. This includes consideration of the importance of origin to perceptions of quality and typicity, in terms of meeting expectations and engaging consumers. Based on the literature reviewed, it is proposed that wine typicity can be defined as a juxtaposition of unique traits that define a class of wines having common aspects of terroir involving biophysical and human dimensions that make the wines recognisable, and in theory, unable to be replicated in another territory.