Red Wine Aroma Research Articles

Comprehensive Analysis of Teran Red Wine Aroma and Sensory Profiles: Impacts of Maceration Duration, Pre-Fermentation Heating Treatment, and Barrel Aging

Comprehensive Analysis of Teran Red Wine Aroma and Sensory Profiles: Impacts of Maceration Duration, Pre-Fermentation Heating Treatment, and Barrel Aging

Study of the fruity aroma of red wines made from grape varieties potentially adapted to climate change using a semi-preparative HPLC method

Under climate change, the fruity aroma of Bordeaux red wines is changing, tending toward undesirable aromas like dried and cooked fruits. To adapt to these changes in aroma, a strategy could be to introduce to Bordeaux vineyards late-ripening grape varieties more suited to drier, sunnier and warmer conditions. A comparative analysis involved traditional Bordeaux red wines (Merlot, Cabernet-Sauvignon, and Cabernet franc) and those from late-ripening grape varieties originating from high-temperature climates (Yiannoudin, Syrah, Agiorgitiko, Xinomavro, Touriga Nacional, Grenache, and Tempranillo). Using a semi-preparative HPLC method, aroma extracts from these ten red wines were fractioned, isolating fruity notes for HPLC–Fruity Aromatic Reconstitutions (FAR). Through a free sorting task, three clusters emerged. Targeted GC-MS analysis highlighted nine compounds characterizing sensory clusters, including ethyl 2-methylpropanoate, ethyl hexanoate, ethyl 6-hydroxyhexanoate, linalool, α-terpineol, α- and β-ionones, hexanol and (Z)-3-hexenol. Through the realization of sensory profiles, it has been demonstrated that by incorporating these compounds into a fruity model solution, fresh red- and black-berry fruit notes are intensified.

Exploring Metschnikowia pulcherrima as a Co-Fermenter with Saccharomyces cerevisiae: Influence on Wine Aroma during Fermentation and Ageing

Non-Saccharomyces yeasts, particularly Metschnikowia pulcherrima, are considered alternatives to SO2 in winemaking, combating specific microorganisms. The sensory profile of the wine is contingent upon the type of yeast, the fermentation conditions, and the concentration and mode of application with Saccharomyces cerevisiae strains (whether pure or used in mixed/sequential co-fermentation). This study assessed the aroma in red wines produced with S. cerevisiae (Sc) and M. pulcherrima (Mp, non-Sc), incorporating variations in the method of addition and the inclusion or exclusion of SO2. The enological parameters of the wines were slightly affected. Volatile compounds were analysed in the wines through gas chromatography–mass spectrometry (GC-MS) at three moments: at the end of malolactic fermentation (MLF) and after 6 and 9 months of bottle ageing. Sequential fermentation of Sc and Mp reduced the concentration of most identified alcohols and acids, which is favourable, as these compounds can yield undesirable aromas at high concentrations. Regardless of the yeast mixture and Mp dose, a majority of the acetate esters and ethyl esters were quantified at concentrations above their perception thresholds, thus enhancing the sensory quality of the wines. Sensory analysis of wines showed generally positive evaluations. Using non-Saccharomyces as an alternative to SO2 improves the aromatic profile of wines.

Aroma Profile of Merlot Red Wine Stored in Stainless-Steel Tanks and Wooden Barrels with Different Toasting Methods.

Stainless-steel tanks and wooden barrels are the most common wine ageing and storage vessels. Wooden barrels are often toasted to improve their chemical composition and influence on wine. The aim of this study was to investigate the changes in Merlot red wine aroma from the 2020 and 2021 vintages during 12-month storage (with sampling every 3 months) in a stainless-steel tank (SST), Excellence oak barrels with medium (EMT), medium plus (EMT+) and medium long (EMLT) toasting and a Premium oak barrel with medium toasting (PMT). The results showed that even slight differences in the time and temperature of medium toasting influenced the extraction of aroma compounds from wood to wine. The changes in individual aroma compounds depended on the vessel type, toasting level, initial wine composition and storage time. An increase in the total concentration of compounds with smoky, spicy and woody notes occurred in both wine vintages stored in wooden barrels, especially during longer storage. In samples from SST, floral, fruity and herbal aromas were more pronounced, according to the gas chromatography and sensory evaluators. Sensory evaluators rated the samples according to the 100-point test, and after 12 months of storage, 2020 and 2021 vintage Merlot stored in PMT obtained the highest points.

Investigating the Role of Odorant-Polymer Interactions in the Aroma Perception of Red Wine: A Density Functional Theory-Based Approach.

The aroma of red wine results from the intricate interplay between aroma compounds (odorants) and complex polymers generated during fermentation. This study combines density functional theory (DFT), human sensory experiments, and nuclear magnetic resonance to investigate the impact of odorant-polymer interactions on wine aroma. Molecular aggregation patterns of odorants with polymer segments are identified, indicating the crucial role of intermolecular noncovalent interactions, such as hydrogen bonds and van der Waals interactions, in stabilizing odorant-polymer conformations. Certain odorants, including 3-isobutyl-2-methoxypyrazine and cis-whisky lactone, exhibit high binding affinity to specific polymer segments, such as (+)-catechin and p-coumaric acid, resulting in substantial changes in the perceived aroma. Their strong binding affinities correlate with changes in sensory experiments for binary mixtures. The results provide insights into the molecular mechanisms of odorant-polymer interactions in red wine with the potential of DFT calculations as a tool for predicting and tailoring red wine aroma.

NMR-Based Studies on Odorant Polymer Interactions and the Influence on the Aroma Perception of Red Wine.

The aroma of red wine is suggested to be influenced by interactions with nonvolatile polymers. To investigate this aroma binding effect in red wine, the key aroma compounds of a Primitivo red wine were quantified using GC-MS and an aroma recombinant with 27 odorants was prepared. In sensory experiments, an overall strong effect on the odor perception of the aroma recombinant was observed when high-molecular-weight (HMW) polymers of Primitivo red wine were added. An 1H NMR-based approach was developed to get an insight into the molecular mechanisms of this aroma binding effect in red wine. Evaluation of qualitative changes in the NMR spectra and quantitative time-dependent measurements revealed a clear distinction between different molecular interaction types: (i) no interactions for esters, alcohols, furanones, ketones, and C13-norisoprenoids, (ii, iii) noncovalent interactions for acids, aldehydes, and lactones, and (iv) π-π interactions for pyrazines and phenols. Additionally, the influence of the molecular weight of polymers was evaluated, where the HMW fraction 30-50 kDa showed the highest interaction activity, for example for π-π interactions. Based on these results, the new approach allowed the direct analysis of noncovalent interactions between odorants and HMW polymers and therefore allowed for the first time the description of the aroma binding effect on a molecular basis.

Development of a New Method for the Quantitative Analysis of Aroma Compounds Potentially Related to the Fruity Aroma of Red Wines.

To determine the concentrations of aroma compounds involved in the fruity aroma of red wines, an analytical method was developed and optimized using liquid-liquid extraction and gas chromatography coupled to mass spectrometry (GC/MS). The aim was to reduce sample preparation and analysis time, with a single sample preparation and a single injection being needed to quantify 43 compounds. 19 esters, 13 monoterpenes, 5 C13-norisoprenoids, and 6 C6-aldehyde and alcohol compounds were quantified in 14 red wines made from different grape varieties grown in the Mediterranean basin. Samples were selected based on typical varietal aroma by a panel of experts, who produced 7 olfactory descriptors linked to desirable or non-desirable wine aromas. The instrumental analysis showed variations in concentrations of the quantified compounds among the wines. The wines described using positive fruity descriptors had higher mean total concentrations of esters, C6-alcohols, monoterpenes, and C13-norisoprenoids. Some non-ester compounds were positively correlated with the fruity descriptors. Sensory profile results obtained by a panel of 16 trained judges revealed that the addition of non-ester compounds (including 2 cyclic esters) to a red wine initially described as having cooked fruit aromas had a positive contribution to some fresh fruity notes. This study opens up new avenues for research on the potential involvement of non-ester compounds in the fruity expression of red wines.

Yeast mannoproteins: Organoleptic modulating functions, mechanisms, and product development trends in winemaking

AbstractMannoproteins (MPs) originate from yeast cells and can play important roles in maintaining wine stability and modulating wine organoleptic properties. Due to their natural presence in wines, MP products are allowed to be used as enological additives in wine industry. To guarantee an appropriate application of these products during winemaking, it is necessary for both researchers and winemakers to understand the mechanisms of MPs as multifunctional organoleptic modulators. This review has introduced the current state of knowledge of the researches focus on the application of different MP products in red wines and also the interactions between MPs and wine sensory active components (polyphenols, aroma compounds) in model wine solutions. We have summarized the possible mechanisms of MPs that affect the color, astringency, and aroma of red wines and the relationship between the physicochemical characteristics and functionalities of MPs. Besides, development trends of MP products are also discussed. It seems that yeast biomass, especially those from non‐Saccharomyces yeasts show good potential in producing large quantities of MPs, an appropriate combination of yeast cultivation and preservation methods with extraction and purification techniques may obtain MPs of ideal production, purity, and functionality in an industrial scale, which should be put more efforts by both scientists and manufacturers in the future.

Ultrasound and microwave techniques as physical methods to accelerate oak wood aged aroma in red wines

The feasibility of accelerating the release of volatile compounds of oak wood chips and aged aroma in wines by ultrasounds and microwaves techniques has been assessed.Despite the influence of the oak wood origin on the extraction of volatile compounds, results showed that wines subjected to treatments of ultrasounds 400 W during 12 h with pulses on/off each hour and microwaves 700 W for 20 min reached similar concentrations of compounds released from oak chips in wines macerated for 8 days. Those wines treated with microwaves exhibited more oak wood related compounds, but ultrasounds enhanced the extraction of more relevant compounds from a sensorial point of view. Consequently, wines with an accelerated ageing assisted by ultrasounds acquired more pronounced aged aromas. Therefore, the use of ultrasound to assist ageing process resulted in an accelerated acquisition of aged aroma which may resemble or even enhance the sensorial profile of wines in contact with oak chips in shorter times.

Wine Cork Closures Impacts on Dimethyl Sulfide (DMS) and Precursors (DMSP) Equilibrium of Different Shiraz Wines during Accelerated Bottle Ageing

Dimethyl sulfide (DMS) is a flavor compound, characteristic of the truffle aroma in red wines, and is well-known to be a fruity exhauster. DMS comes from the degradation of dimethyl sulfide potential (DMSP) during winemaking. Up to now, little is known about the role of the closure on the DMSP degradation during ageing. For that purpose, the effect of four micro-agglomerated wine cork closures was studied on the DMS/DMSP equilibrium, along with six other volatile sulfur compounds (VSC), was investigated in six Shiraz wines. After three months of accelerated bottle ageing, DMS levels increased significantly in all bottles. The most permeable closures induced a lesser accumulation of DMS, suggesting that DMS could be dependent on the redox status of the wine. At the same time, the DMSP decrease was proportional to the permeability of the closures. For the first time, a possible implication of closure permeability on DMSP degradation was observed.

Effects of Frozen Materials Other Than Grapes on Red Wine Aroma Compounds. Impacts of Harvest Technologies

An undesirable sensory attribute (“floral taint”) has been detected in red wines in North America, caused by leaves and petioles (materials other than grapes [MOG]) introduced during mechanical harvest after killing frosts. From 2017 to 2019, several harvest strategies were evaluated on Ontario Cabernet franc: hand harvest (HH), conventional machine harvesting (MECH), Braud-New Holland Opti (OPTI), Gregoire GL8, MECH + optical sorting (MECH+OS), and MECH with preharvest leaf removal (MECH+BLR). Concentrations of 41 odor-active compounds were quantified by gas chromatography-mass spectrometry. Harvest treatment effects varied by season. In 2017, HH resulted in lowest ethyl isobutyrate (MECH+BLR), ethyl nonoate, cis-linalool oxide (plus MECH and OPTI), trans-linalool oxide (plus MECH+OS), β-citral, and cis- and trans-rose oxide (plus MECH and OPTI). Ethyl hexanoate was lowest in MECH, and MECH+BLR, isoamyl hexanoate was lowest in all treatments except HH, and α-ionone was lowest in MECH and MECH+BLR. In 2018, HH resulted in the lowest β-damascenone, ethyl salicylate (plus OPTI and Gregoire), citronellol (plus Gregoire), cis- and trans-rose oxide (plus Gregoire), and eugenol (plus Gregoire). Isobutyl acetate, isoamyl hexanoate, and nerol were additionally reduced by Gregoire, and isopropylmethoxypyrazine was reduced by all treatments except HH. In 2019, harvest strategy affected 27 of 41 compounds, including 11 esters and 12 terpenes. Treatments leading to lowest concentrations were HH (nine compounds), MECH (eight compounds), MECH+BLR (10 compounds), OPTI (21 compounds), Gregoire (10 compounds), and MECH+OS (22 compounds). Wines from fruit that had undergone a killing frost contained different concentrations of 14 and eight compounds (2018), and 17 and 13 compounds (2019) for Cabernet franc and Cabernet Sauvignon, respectively. Results suggest that specific harvest technologies can reduce MOG and associated increases in aroma compounds, although seasonal differences may occur.

Modulation of Volatile Thiol Release during Fermentation of Red Musts by Wine Yeast

During the alcoholic fermentation of grape sugars, wine yeast produces a range of secondary metabolites that play a critical role in the aroma profile of wines. One of the most impactful yeast-modified compound families, particularly in white wines, are the ‘fruity’ polyfunctional thiols, which include 3-mercaptohexan-1-ol (3-MH) and 4-mercapto-4-methylpentan-2-one (4-MMP). While the formation and stylistic contribution of these thiols have been extensively researched in white wines, little is known about the conditions leading to their formation in red wines. In this study, we explored the ability of yeast strains to modulate the release of these aroma compounds during the fermentation of two red musts. In laboratory-scale Pinot Noir fermentations, the formation of 3-MH strongly correlated with yeast β-lyase activity, particularly with the presence of certain genotypes of the flavour-releasing gene IRC7. Subsequent production of Grenache wine at the pilot scale, with detailed compositional and sensory analysis, was undertaken to confirm laboratory-scale observations. A commercial wine strain used for expressing ‘fruity’ thiols in Sauvignon Blanc was shown to produce wines that exhibited more intense red fruit aromas. These results reveal an opportunity for winemakers to shape red wine aroma and flavour by using yeasts that might typically be considered for white wine production.

Measurement of the Effect of Accelerated Aging on the Aromatic Compounds of Gewürztraminer and Teroldego Wines, Using a SPE-GC-MS/MS Protocol.

Knowing in detail how the white and red wine aroma compounds behave under various storage conditions and especially at high temperature is important in order to understand the changes occurring to their sensorial character during the shelf life. The initial aim of this work was to develop and validate a fast, modern, robust, and comprehensive protocol for the quantification of 64 primary, secondary, and tertiary volatile compounds by using solid-phase extraction (SPE) cartridges in sample preparation and fast GC-MS/MS (gas chromatography-tandem mass spectrometry assay) in analysis. The protocol was applied to a study of the behavior of seven Gewürztraminer and seven Teroldego wines stored in anoxia at 50 °C for 2.5 and 5 weeks. The results demonstrated a sharp decrease of the main linear terpenes linalool, geraniol, and nerol and the consequent increase of the cyclic ones, such as α-terpineol and 1,8-cineole; the increase of the C13-norisoprenoids 1,1,6,-trimethyl-1,2-dihydronapthalene (TDN), and β-damascenone and the C10 norisoprenoid safranal; the hydrolysis of acetates and linear esters; and the increase of some branched-chain esters. In red wines, a moderate increase was observed for some lactones. Some unwanted compounds, such as 2-aminoacetophenone (2-AAP), showed a notable increase in some Gewürztraminer wines, exceeding the olfactory threshold.

Investigating the Effect of Yeasts and their Derivatives on the Qualitative Indices of Red Wine

The study on the influence of yeast and yeast derivative autolyzes on the wine qualitative and quantitative characteristics has been conducted upon the first article of the series. Red grapes contain more than 1500 components, which are forming the taste and aroma of red wines, as well as the biological value of the product. One of the main technological operations in the production of red wines, which is related to the creation of favorable conditions for extracting phenolic and coloring compounds from the solid parts of the grape berry that are responsible for the color, taste, and aroma preserving them at the different stages of the wine formation and maturation, has been researched and analyzed.

Impact of two yeast strains on Tempranillo red wine aroma profiles throughout accelerated ageing

This study aimed at determining the changes induced by two S. cerevisiae strains, (IONYS wf™ and Lalvin ICV D254™) on the sensory and chemical aroma profiles of Tempranillo wine, after fermentation and after ageing. The 64 aroma molecules determined were grouped attending to sensory and chemical similarity into 17 aroma vectors. Sensory studies included a sorting task and a descriptive analysis by flash profile with a trained panel. Results revealed that, even if ageing is the dominant factor, the strain of yeast introduces significant and consistent differences, both in sensory and aroma vector profiles (11 out of 17 affected). Wines made with D254 contained higher levels of ethyl esters, acetic acid, cinnamates and ethyl acetate and lower levels of linear fatty acids, β-damascenone, acetaldehyde, higher alcohols and lactones than those made with IONYS. The first profile was related to black and fresh fruit notes, while the second to white and compote fruits.

Effects of oenological tannins on aroma release and perception of oxidized and non-oxidized red wine: A dynamic real-time in-vivo study coupling sensory evaluation and analytical chemistry

Addition of oenological tannins claims to have a positive impact on wine stability, protection from oxidation and likely sensory persistence. However, their role on red wine aroma during oxidation is controversial. The present study aims at investigating the effect of addition of oenological tannins on wine flavour (mainly aroma) before and after air exposure. Temporal Dominance of Sensations, a dynamic sensory evaluation, was coupled with a dynamic chemical measurement (nosespace analysis) using a Proton-Transfer-Reaction Mass-Spectrometer connected to the nasal cavity of 17 assessors. Results showed that the oxidation of a non-oaked Pinot Noir red wine decreases the fruity aroma dominance and increases the maderised and prune one. A contextual decrease of the fruity ethyl decanoate and increase of oxidative Strecker aldehydes are observed. Ellagitannins but not proanthocyanidins preserved perception of fruitiness and prevented increase of maderised notes. Moreover, ellagitannins increase the aroma persistence mainly in the non-oxidized wine.

Olfactometric and sensory evaluation of red wines subjected to ultrasound or microwaves during their maceration or ageing stages

In the present work, we have studied the effect that some extraction techniques, such as ultrasound or microwaves, produce on the aroma of red wines, when applied to processes of extractive nature, such as pre-fermentative maceration or ageing with oak chips (Spanish oak – Quercus pyrenaica and French oak – Quercus robur). The volatile profile has been studied by means of gas chromatography coupled with olfactometric and mass spectrometric detection. Sensory analysis of all the wines produced has also been conducted. Although no indications were found to show that the pre-fermentative treatment with microwaves or ultrasound modified the sensory profile of the wines, the application of such energies during the ageing phase showed some positive trends at sensory level, also confirmed by the olfactometric measurements. The application of ultrasound during the ageing of the wines resulted in a greater contribution of red fruits, aromatic intensity and wood than that obtained through microwaves. Regarding the type of oak chips, Spanish oak provided more volatile compounds than French oak and with a lower proportion of undesirable aromas. At the sensory level, Spanish oak also showed greater aromatic intensity and higher values for the wood descriptor, being preferred by the panel of judges.

Investigating the effects of two volatile phenols on aroma perception of four red wine cultivars using Projective Mapping

AbstractPerception of aroma compounds in wine is the result of complex phenomena, in which the compounds, their concentrations, the matrix, and their interactions play a role. In order to evaluate the impact of compounds and matrices on red wine aroma perception, a two‐part study was conducted. First, the work evaluated Projective Mapping (PM) and Descriptive Analysis (DA) in assessing olfactory interactions in a large (n = 18) set of red wine samples. Both methods generated a rich and comparable set of descriptors (21 and 28 for DA and PM, respectively), indicating that the rapid method was fit for purpose. Subsequently, PM was used to test the olfactory effects of 4‐ethyl phenol (4‐EP) and o‐cresol in four red cultivars by a trained panel of twelve judges. There were marked similarities in the impact of these compounds in all cultivars regarding aspects such as loss of fruitiness. However, important differences in the sensory profiles of similarly spiked samples were also observed, highlighting the importance of matrix effects.Practical ApplicationsThe results confirm that work related to wine matrices can be carried out with a trained panel using PM rather than DA. This finding suggests that limiting aspects of DA (e.g., the large number of samples generated through experimental design) can be addressed through careful choice of evaluation method, while taking into account the fine balance between gain and loss of relevant information. The study furthermore emphasizes the need to carefully consider the composition of the matrix when determining and comparing olfactory perceptual interactions in wine, and when evaluating the effects of treatments on wine aroma.

Influence of must yeast-assimilable nitrogen content on fruity aroma variation during malolactic fermentation in red wine

This study assessed the impact of must yeast-assimilable nitrogen (YAN) content and lactic acid bacteria (LAB) strains used for malolactic fermentation (MLF) on the formation of substituted esters, as well as the corresponding precursors (substituted acids), to investigate the modulation of fruity expression in red wines. In microvinification experiments, a Merlot must was fermented with an initial YAN content of 111 mg/L, or supplemented up to 165 and 220 mg/L. Two Oenococcus oeni LAB strains were used for MLF. Analytical methods were used to quantify substituted esters, as well as the corresponding acids, including, any enantiomeric forms. YAN supplementation of the must significantly increased concentrations of substituted esters of short- and branched-chain alkyl fatty acids produced during alcoholic fermentation (AF) (up to 67% in samples with the highest nitrogen content) and substituted esters of hydroxycarboxylic acids generated during MLF (up to 58% in samples with the highest nitrogen content). YAN supplementation in the must did not affect substituted acid formation during AF. After MLF, short- and branched-chain alkyl fatty acid levels increased in wines made from musts with the highest nitrogen content (up to 56% in samples with the highest nitrogen content), whereas concentrations of hydroxycarboxylic acids increased (up to 55%) independently of the initial YAN content, highlighting the important role of MLF. (2S)-2-hydroxy-4-methylpentanoic acid was only found in wines after malolactic fermentation, suggesting different pathways for each enantiomer and opening up new prospects for the study of bacterial metabolisms. Moreover, sensory profiles revealed a significant increase in black-berry- and jammy-fruit aromas during MLF and a strong positive correlation between these aromas and the production of substituted esters following must nitrogen supplementation and MLF. Aromatic reconstitutions revealed that variations in the concentrations of substituted esters after MLF impacted the fruity aroma of red wines.

Discrimination of Red Wines with a Gas-Sensor Array Based on a Surface-Acoustic-Wave Technique.

We applied a thermal-desorption gas-chromatograph mass-spectrometer (TD-GC–MS) system to identify the marker volatile organic compounds (VOCs) in the aroma of red wine. After obtaining the marker VOC, we utilized surface acoustic waves (SAWs) to develop a highly sensitive sensing system as ‘electronic nose’ to detect these marker VOC. The SAW chips were fabricated on a LiNbO3 substrate with a lithographic process. We coated sensing polymers on the sensing area to adsorb the marker VOC in a sample gas. The adsorption of the marker VOC altered the velocity of the SAW according to a mass-loading effect, causing a frequency decrease. This experiment was conducted with wines of three grape varieties—cabernet sauvignon, merlot and black queen. According to the results of TD-GC–MS, the King brand of red wine is likely to have unique VOC, which are 2-pentanone, dimethyl disulfide, 2-methylpropyl acetate and 2-pentanol; Blue Nun-1 probably has a special VOC such as 2,3-butanedione. We hence used a SAW sensor array to detect the aroma of red wines and to distinguish their components by their frequency shift. The results show that the use of polyvinyl butyral (PVB) as a detecting material can distinguish Blue Nun-2 from the others and the use of polyvinyl alcohol (PVA) can distinguish King from the others. We conducted random tests to prove the accuracy and the reliability of our SAW sensors.