Wine Composition Research Articles

Soil Microbial Communities and Wine Terroir: Research Gaps and Data Needs.

Microbes found in soil can have a significant impact on the taste and quality of wine, also referred to as wine terroir. To date, wine terroir has been thought to be associated with the physical and chemical characteristics of the soil. However, there is a fragmented understanding of the contribution of vineyard soil microbes to wine terroir. Additionally, vineyards can play an important role in carbon sequestration since the promotion of healthy soil and microbial communities directly impacts greenhouse gas emissions in the atmosphere. We review 24 studies that explore the role of soil microbial communities in vineyards and their influence on grapevine health, grape composition, and wine quality. Studies spanning 2015 to 2018 laid a foundation by exploring soil microbial biogeography in vineyards, vineyard management effects, and the reservoir function of soil microbes for grape-associated microbiota. On the other hand, studies spanning 2019 to 2023 appear to have a more specific and targeted approach, delving into the relationships between soil microbes and grape metabolites, the microbial distribution at different soil depths, and microbial influences on wine flavor and composition. Next, we identify research gaps and make recommendations for future work. Specifically, most of the studies utilize targeted sequencing (16S, 26S, ITS), which only reveals community composition. Utilizing high-throughput omics approaches such as shotgun sequencing (to infer function) and transcriptomics (for actual function) is vital to determining the specific mechanisms by which soil microbes influence grape chemistry. Going forward, understanding the long-term effects of vineyard management practices and climate change on soil microbiology, grapevine trunk diseases, and the role of bacteriophages in vineyard soil and wine-making would be a fruitful investigation. Overall, the studies presented shed light on the importance of soil microbiomes and their interactions with grapevines in shaping wine production. However, there are still many aspects of this complex ecosystem that require further exploration and understanding to support sustainable viticulture and enhance wine quality.

Comparison of pre-fermentation and post-fermentations alcohol adjustments on aromatic chemistry and sensory composition of Sauvignon blanc wine

Harvest and alcohol adjustment effects were evaluated for Sauvignon blanc grapes harvested at three potential alcohols (11, 13 and 15% (v/v)) by gas chromatography–mass spectrometry and descriptive analysis. Alcohol concentration was controlled for pre-fermentation by dilution or chaptalization and post-fermentation by dealcoholization. The initial experimental alcohol was treated as the control and the dealcoholized wine the treatment. Wine treatments sharing the same alcohol target and harvest date as the dealcoholized wine were designated as the negative control. All aroma compounds measured increased because of higher ethanol or declined because of dealcoholization. Similar aroma concentrations were observed to be a factor of alcohol concentration, apart from volatile thiols which were influenced by harvest. Statistical analysis of sensory and aroma compounds showed a corresponding relationship between low versus high alcohol wines. Dealcoholization appears to be an effective tool for altering wine aroma and winemaking style with comparable aroma loss to pre-fermentation adjustment.

Exploring Corbières red wine typicity: evaluation of the impact of winemaking processes on the chemical composition and organoleptic properties of wines from different terroirs

Aromatic and polyphenolic compounds play an important role in the quality of red wines, contributing not only to flavour, but also to colour, astringency and bitterness. To explore the influence of climate and oenological practices on the chemical and sensory profile of wines, red blends from five terroirs of the Corbières appellation were analysed, taking into account two production years (2018 and 2019). The wines were a blend of at least two of four main grape varieties: Syrah, Grenache, Carignan and Mourvèdre. Volatile compounds were evaluated by HS-SPME-GC-MS, while wine pigments and derived pigments were evaluated by spectrophotometric measurements. In addition, the wines were compared using a quantitative descriptive analysis sensory profile method. The percentage of the blend significantly influenced the polyphenolic and aromatic characteristics of the wines, showing distinct 'typicity' characteristics between sub-regions. Maceration techniques, on the other hand, did not did not allow us to discriminate between sub-regions, but enabled a better understanding of chemical and sensory differences between samples.

Effect of sequential fermentation with indigenous non-Saccharomyces cerevisiae combinations and Saccharomyces cerevisiae on the chemical composition and aroma compounds evolution of kiwifruit wine

To unlock the potential of indigenous non-Saccharomyces cerevisiae and develop novel starters to enhance the aromatic complexity of kiwifruit wine, Zygosaccharomyces rouxii, Pichia kudriavzevii and Meyerozyma guilliermondii were pairwise combined and then used in sequential fermentation with Saccharomyces cerevisiae. The impact of different starter cultures on the chemical composition and flavor profile of the kiwifruit wines was comprehensively analyzed, and the aroma evolution during alcoholic fermentation was investigated by examining the changes in key volatiles and their loss rates. Compared with Saccharomyces cerevisiae, mixed starter cultures not only improve antioxidant capacity but also increase esters and alcohols yields, presenting intense floral and fruity aromas with high sensory acceptability. The results indicated that sequential inoculation of non-Saccharomyces cerevisiae combination and Saccharomyces cerevisiae promoted the development of volatiles while maintaining the stability of key aroma compounds in the winemaking environment and reducing the aroma loss rates during alcoholic fermentation.

From tyrosine to hydroxytyrosol: a pathway involving biologically active compounds and their determination in wines by ultra performance liquid chromatography with mass spectrometry.

Hydroxytyrosol (HT) is a bioactive compound present in a limited number of foods such as wines, olives, and olive oils. During alcoholic fermentation, yeast converts aromatic amino acids into higher alcohols such as tyrosol, which can undergo hydroxylation into HT. The aim of this study was to validate an analytical method using ultra performance liquid chromatography coupled with mass spectrometry (UPLC/MS-MS) to quantify HT and its precursors (tyrosine, hydroxyphenylpyruvic acid, hydroxyphenylacetaldehyde, 4-hydroxyphenylacetic acid, and tyrosol) in wines. Their occurrence was evaluated in a total of 108 commercial Spanish wine samples. The validated method simultaneously determined both HT and its precursors, with adequatelimits of detection between 0.065 and 21.86 ng mL-1 and quantification limits between 0.199 and 66.27 ng mL-1 in a 5 min run. The concentration of HT in red wines was significantly higher (0.12-2.24 mg L-1) than in white wines (0.01-1.27 mg L-1). The higher the alcoholic degree, the higher was the content of HT. The bioactive 4-hydroxyphenylacetic acid was identified in Spanish wines for the first time at 3.90-127.47 mg L-1, being present in all the samples. The highest HT concentrations were found in red wines and in wines with higher ethanol content. These data are useful for a further estimation of the intake of these bioactive compounds and to enlarge knowledge on chemical composition of wines. © 2024 The Author(s). Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Correlation of chemical composition and sensory scores in Spanish Monastrell red wines: Insights from a blind wine competition

Red wine is a complex beverage, both chemically and sensorially, making it a very interesting beverage from a sensory perspective. Additionally, wine offers consumers a multitude of choices and brands. Considering this diversity, wine competitions and scoring could provide a way of helping consumers in their choices. In this study, sixty-seven commercial Spanish Monastrell red wines, which participated in an official blind contest, were grouped into different winemaking categories based on aging and wood contact. These wines were chemically analyzed to explore relationships between their allocated groups and their chemical composition. Additionally, the study aimed to find correlations between the total scores given in the contest and the wines' volatile compounds, chromatic parameters, and physicochemical properties. The goal was also to identify the chemical parameters that most strongly correlated with the obtained scores. Considering all 67 wines, the results showed a significant linear regression between the wine scores and their physicochemical and volatile compounds, with a coefficient of determination of 48.4 %. However, when the wines were analyzed considering the different categories, the coefficient of determination for those wines competing in the category of aged wines increased up to 84.8 %. In addition, some wine chromatic characteristics such as color intensity, total phenol index and polymeric anthocyanin seemed to be highly related to the score received for the wines in a contest. Therefore, the results obtained in this work can be useful to define a certain style of wine that most probably could get a higher score in a wine contest.

Automatic Chemical Profiling of Wine by Proton Nuclear Magnetic Resonance Spectroscopy.

We report the development of MagMet-W (magnetic resonance for metabolomics of wine), a software program that can automatically determine the chemical composition of wine via 1H nuclear magnetic resonance (NMR) spectroscopy. MagMet-W is an extension of MagMet developed for the automated metabolomic analysis of human serum by 1H NMR. We identified 70 compounds suitable for inclusion into MagMet-W. We then obtained 1D 1H NMR reference spectra of the pure compounds at 700 MHz and incorporated these spectra into the MagMet-W compound library. The processing of the wine NMR spectra and profiling of the 70 wine compounds were then optimized based on manual 1H NMR analysis. MagMet-W can automatically identify 70 wine compounds in most wine samples and can quantify them to 10-15% of the manually determined concentrations, and it can analyze multiple spectra simultaneously, at 10 min per spectrum. The MagMet-W Web server is available at https://www.magmet.ca.

Maceration duration and grape variety: key factors in phenolic compound enrichment of Montenegrin red wine

The present study focuses on the effect of increasing maceration times (0, 2, 4, 6, and 10 days) on the extraction of phenolic compounds into two Montenegrin wines made with the autochthonous varieties Vranac and Kratošija. Significant differences were found in the total acidity, pH and alcohol content of these two varietal wines, which showed different responses to the maceration time. The total content of phenolic compounds (phenols, tannins and anthocyanins) increased significantly with longer maceration time, which is consistent with the existing literature. Specifically, the longest maceration time (10 days) consistently resulted in the highest levels of all parameters analysed. In addition, the anthocyanin profile determined by HPLC showed the interaction between maceration time and variety on the concentrations of the individual anthocyanins. Compared to Kratošija, Vranac wines consistently showed higher anthocyanin contents. In addition, the structural analysis of the tannins revealed that the mean degree of polymerisation (mDP), the percentage of prodelphinidins (%PD) and the percentage of galloylation (%Gall) changed with increasing maceration time. Significant correlations were found between the antioxidant activity values and the analytical parameters, including the structural characteristics of the tannins. This study provides important information on the interaction between maceration time and various varietal characteristics that influence the phenolic composition of Montenegrin wines and contributes to a deeper understanding of winemaking practices and wine quality.

A comprehensive study on the effect of foliar mineral treatments on grapevine epiphytic microorganisms, flavonoid gene expression, and berry composition

Foliar treatments with mineral-based compounds have aroused interest as a sustainable approach to cope with high-temperature stress in vineyards, improving the colour of grapes and wines without altering the sugar concentration. Since berry-associated microorganisms are crucial for wine production, composition and stability, the present study aims to unravel the effects of kaolin and zeolite treatments on berry quality, flavonoid gene expression and epiphytic microorganisms (total fungi, Hanseniospora uvarum, Metschnikowia pulcherrima, plant-associated bacteria and lactic acid bacteria). Experiments were performed on 'Sangiovese' during ripening in two growing seasons (2019 and 2020). Both mineral treatments were able to cause the elicitation of several flavonoid-related genes and to increase the anthocyanin concentration in berries without an alteration of the final technological maturity (TSS, TA, pH) of the grapes. Interestingly, neither kaolin nor zeolites negatively affected the analysed microbial population at harvest despite transient alterations observed in the more stressful year (2019). These results support the use of foliar mineral treatments to increase anthocyanin concentration in grape berries and protect them from excessive heat without altering their native microorganisms.

Assessing chemical composition variations on vintage, vineyard location and grape ripeness: A regional study of red wines produced in the colorado river middle basin, La Pampa (Argentina)

This work aimed to characterize chemical composition of Malbec and Cabernet Franc red wines from two different regions of La Pampa’s province, which stands out as one of the youngest wine-producing regions in Argentina and has remained unexplored until now. These wines were produced from grapes of two consecutive vintages (2021 and 2022), and were harvested at two different ripeness levels. Global phenolic parameters, colour characterization and multi-elemental profile were evaluated. Multivariate statistical approaches were successfully implemented to investigate the vintage and ripeness effects on chemical profile of red wines and characterize them based on regional variations. Our results showed that vintage and ripeness affected both phenolic and multi-elemental profiles, and such chemical variables allowed the wines differentiation according to region. The results of this first study could form the basis for future research into optimizing the region’s winemaking potential.

Chemical Characterization of Sauvignon Blanc Wines from Three Cold-Climate-Growing Areas of Chile.

The influence of the geographical location on the chemical composition of commercial Sauvignon Blanc wines was investigated. The assay was carried out on Sauvignon Blanc wines from three cold-climate valleys in Central Chile, Casablanca, Leyda, and San Antonio. The analyses revealed clear variations in some chemical parameters, especially in titratable acidity, which was higher in the geographical areas closest to the Pacific Ocean, such as the Leyda and San Antonio valleys. Regarding the composition of low-molecular-weight phenolic compounds, 17 compounds were found, and the results show that the Casablanca valley exhibits a greater abundance of monomeric flavanols, such as (+)-catechin, whereas the Leyda valley shows a higher abundance in flavonols and phenolic acids esterified with tartaric acid. Concerning the aromatic compound profile, the wines from the Casablanca valley showed a greater abundance of esters, C13 norisoprenoids, and some terpenes. The PLS-DA analysis revealed some differences, especially between wines from Casablanca and Leyda, demonstrating that the difference in the chemical composition of the wines was influenced by the geographical area.

Copper (II) Level in Musts Affects Acetaldehyde Concentration, Phenolic Composition, and Chromatic Characteristics of Red and White Wines.

Copper (II), a vital fungicide in organic viticulture, also acts as a wine oxidation catalyst. However, limited data are currently available on the impact that maximum allowed copper (II) ion doses in wine grapes at harvest can have on aged wine quality. This was the focus of the present study. We investigated the copper (II) effects by producing both white and red wines from musts containing three initial metal concentrations according to the limits set for organic farming. In detail, the influence of copper (II) on fermentation evolution, chromatic characteristics, and phenolic compounds was evaluated. Interestingly, the white wine obtained with the highest permitted copper (II) dose initially exceeded the concentration of 1.0 mg/L at fermentation completion. However, after one year of storage, the copper (II) content fell below 0.2 ± 0.01 mg/L. Conversely, red wines showed copper (II) levels below 1.0 mg/L at the end of fermentation, but the initial copper (II) level in musts significantly affected total native anthocyanins, color intensity, hue, and acetaldehyde concentration. After 12-month aging, significant differences were observed in polymeric pigments, thus suggesting a potential long-term effect of copper (II) on red wine color stability.

Untargeted Metabolomics Analysis Based on LC-QTOF-MS to Investigate the Phenolic Composition of Red and White Wines Elaborated from Sonicated Grapes.

Ultrasounds are considered an emerging technology in the wine industry. Concretely, in 2019, the International Organization of Vine and Wine (OIV) officially approved their use for the treatment of crushed grapes to increase the level of phenolic compound extraction. The main objective of this study was to validate an untargeted metabolomics approach as an analytical tool for identifying novel markers associated with sonication. To do so, the influence of a sonication treatment on the metabolic profile was studied in four typically commercial varietal wines, i.e., two red wines from 'Syrah' and 'Cabernet Sauvignon' grapes and two white wines from 'Macabeo' and 'Airén' grapes. A robust classification and prediction model was created employing supervised techniques such as partial least-squares discriminant analysis (PLS-DA). The findings indicated that the grapes subjected to high-power ultrasound conditions experienced cell wall disruption due to the cavitation phenomenon, resulting in significant changes in various phenolic compounds (including hydroxycinnamic acids and flavonoids) present in these wines compared to wines from non-sonicated grapes. Additionally, new metabolites were tentatively identified through untargeted metabolomics techniques. This study represents the successful application of the untargeted metabolomics approach employing a UHPLC-QTOF system to discern how grape sonication affects bioactive secondary metabolites in wines.

Chemical and sensory profile of nonconventional white wines from two different grape clones

AbstractThe present study aimed to characterize chemical and sensorial composition of Goethe wines from Goethe Grape's Valley Geographical Indication, Brazil. The wine samples were made from Goethe Clássica grape and its spontaneous clone, Goethe Primo, grown in two different micro‐regions located in the GI territory (2022 and 2023 vintages). Samples were produced by microvinification process and evaluated for classic oenological parameters, antioxidant activity, total polyphenol, organic acids, and sensory descriptive analysis. The results demonstrated that Goethe Clássica wines presented highest browning index, total acidity, antioxidant activity, and total phenolic content in both consecutive vintages. Moreover, in both vintages, the major organic acid in all Goethe wines was malic acid. The wine sensory analysis allowed the accomplishment of the sensorial attributes and its intensities previously unknown in the literature. The overall data afford new insights related to the impact of grape's genetic differences on wine sensorial and chemical characteristics.Practical ApplicationsThis research supports evidence for the relationship between chemical and sensory properties of wine and the sensorial differences in wines due to grape clonal variation. Moreover, the present study detailed the chemical and sensory profiles of wines derived from two different Goethe grape clones, a variety considered nonconventional for winemakers. Overall, the results of this research might be beneficial not only for the producers who are exploring novel or less prevalent wine grape varieties but also to the beverage industry more comprehension through genetic differences influencing wine quality and sensory perceptions.

Volatile composition and aromatic descriptors of red wines from different regions of Bulgaria aged with oak chips

http://nuft.edu.ua/doi/doc/ufj/2024/2/5.pdf

Impact of Various Prefermentation Treatments on the Pigment, Polyphenol, and Volatile Composition of Industrial Red Wines Made from Vitis vinifera cv Maratheftiko

Impact of Various Prefermentation Treatments on the Pigment, Polyphenol, and Volatile Composition of Industrial Red Wines Made from Vitis vinifera cv Maratheftiko

Use of high hydrostatic pressure and non-Saccharomyces yeasts for improving aging on lees of white wine

This study aimed to assess the impact of different fermentation lees on enhancing the chemical composition, volatile profile, and sensory characteristics of wine during aging, specifically in relation to autolysis induction treatments. Lees processed by high hydrostatic pressure, especially those obtained from sequential fermentation (Hanseniaspora spp. followed by Saccharomyces spp.) determined the best color evolution, the highest protection against oxidation together with an overall improvement of volatile profile; these aged wines also obtained the highest scores in floral and fruity notes, resulting the most preferred by the panel. An improvement of the overall wine quality might be reached, by modulating lees composition (i.e., non-Saccharomyces spp. as fermentation co-starters), then by applying high hydrostatic pressure as alternative to enzyme addition for managing the subsequent aging on lees. This might possibly implement and improve the current winemaking process with an innovative, sustainable approach.

Pectin forms polymeric pigments by complexing anthocyanins during red winemaking and ageing

The long-term stability of red wine color depends on the formation of polymeric pigments from anthocyanins. Although there is still a lot of uncertainty about the specific structure of this diverse group of pigments, there is consensus that they are reaction products of anthocyanins and other polyphenols. Interactions between anthocyanins and pectic polysaccharides have been suggested to stabilize anthocyanins. This study explores the impact of such interactions by adding pectin during red winemaking.The results demonstrate that these interactions induce the formation of additional polymeric pigments which enhance the pigment stability during fermentation and aging. While initial pigment formation is higher in wines with added pectin, a notable proportion of the complexes degrades in the later stages of fermentation. Presumably, tannins form insoluble complexes with pectin, reducing tannin concentration by more than 300 mg/L. Anthocyanin concentrations decrease by over 400 mg/L, and polymeric pigments double.Anthocyanins that form polymeric pigments with pectic polysaccharides expand the range of pigments in red wines with possible consequences for the sensory properties of the wine. These findings highlight the complex interactions between pectin, anthocyanins, and tannins, and their influence on pigment formation and wine composition during fermentation and aging.

Comprehensive Analysis of Physicochemical Properties and Volatile Compounds in Different Strawberry Wines under Various Pre-Treatments.

Pre-fermentation treatment has an important impact on the color, aroma, taste, and other characteristics of fruit wine. To discover suitable pre-treatment techniques and conditions that yield strawberry wine of excellent quality, the influences of juice fermentation, pulp maceration, thermovinification, and enzymatic hydrolysis pre-treatments on the basic chemical composition, color, antioxidant capacity, and volatile organic compounds in strawberry wines were investigated. The results showed that the color, antioxidant properties, and volatile aroma of strawberry wines fermented with juice were different from those with pulp. Strawberry wines fermented from juice after 50 °C maceration had more desirable qualities, such as less methanol content (72.43 ± 2.14 mg/L) compared with pulp-fermented wines (88.16 ± 7.52 mg/L) and enzymatic maceration wines (136.72 ± 11.5 mg/L); higher total phenolic content (21.78%) and total flavonoid content (13.02%); enhanced DPPH (17.36%) and ABTS (27.55%) free radical scavenging activities; richer essential terpenoids and fatty acid ethyl esters, such as linalool (11.28%), ethyl hexanoate (14.41%), ethyl octanoate (17.12%), ethyl decanoate (32.49%), and ethyl 9-decenoate (60.64%); pleasant floral and fruity notes compared with juice-fermented wines macerated at normal temperatures; and a lighter color. Overall, juice thermovinification at 50 °C is a potential pre-treatment technique to enhance the nutrition and aroma of strawberry wine.

Machine Learning Model Stability for Sub-Regional Classification of Barossa Valley Shiraz Wine Using A-TEEM Spectroscopy.

With a view to maintaining the reputation of wine-producing regions among consumers, minimising economic losses caused by wine fraud, and achieving the purpose of data-driven terroir classification, the use of an absorbance-transmission and fluorescence excitation-emission matrix (A-TEEM) technique has shown great potential based on the molecular fingerprinting of a sample. The effects of changes in wine composition due to ageing and the stability of A-TEEM models over time had not been addressed, however, and the classification of wine blends required investigation. Thus, A-TEEM data were combined with an extreme gradient boosting discriminant analysis (XGBDA) algorithm to build classification models based on a range of Shiraz research wines (n = 217) from five Barossa Valley sub-regions over four vintages that had aged in bottle for several years. This spectral fingerprinting and machine learning approach revealed a 100% class prediction accuracy based on cross-validation (CV) model results for vintage year and 98.8% for unknown sample prediction accuracy when splitting the wine samples into training and test sets to obtain the classification models. The modelling and prediction of sub-regional production area showed a class CV prediction accuracy of 99.5% and an unknown sample prediction accuracy of 93.8% when modelling with the split dataset. Inputting a sub-set of the current A-TEEM data into the models generated previously for these Barossa sub-region wines yielded a 100% accurate prediction of vintage year for 2018-2020 wines, 92% accuracy for sub-region for 2018 wines, and 91% accuracy for sub-region using 2021 wine spectral data that were not included in the original modelling. Satisfactory results were also obtained from the modelling and prediction of blended samples for the vintages and sub-regions, which is of significance when considering the practice of wine blending.