Wine Aroma Compounds Research Articles

Pulsed electric field processing of white grapes (cv. Garganega): Effects on wine composition and volatile compounds

Pulsed electric field (PEF) processing of white grapes (cv. Garganega) after crushing was studied on pilot-plant scale, to investigate the effects of the treatment on must and wine composition, wine color and predisposition to browning, wine aroma compounds and extraction of aroma precursors from grapes. PEF pre-treatment of grapes did not change the must or wine basic composition, nor was it able to modify the evolution of alcoholic fermentation. By contrast, PEF produced an increase in total dry extract, wine color and total phenolics. Treatment corresponding to a total specific energy of 22 kJ kg−1 allowed more intense extraction of varietal aroma precursors without provoking excessive color evolution and extraction of phenolic compounds, apparently increasing the stability of wine towards oxidation. Due to the few papers available on this subject, PEF applications on white grapes should be optimized in further experiments.

Determination of Selected Aromas in Marquette and Frontenac Wine Using Headspace-SPME Coupled with GC-MS and Simultaneous Olfactometry

Understanding the aroma profile of wines made from cold climate grapes is needed to help winemakers produce quality aromatic wines. The current study aimed to add to the very limited knowledge of aroma-imparting compounds in wines made from the lesser-known Frontenac and Marquette cultivars. Headspace solid-phase microextraction (SPME) and gas chromatography-mass spectrometry (GC-MS) with simultaneous olfactometry was used to identify and quantify selected, aroma-imparting volatile organic compounds (VOC) in wines made from grapes harvested at two sugar levels (22° Brix and 24° Brix). Aroma-imparting compounds were determined by aroma dilution analysis (ADA). Odor activity values (OAV) were also used to aid the selection of aroma-imparting compounds. Principal component analysis and hierarchical clustering analysis indicated that VOCs in wines produced from both sugar levels of Marquette grapes are similar to each other, and more similar to wines produced from Frontenac grapes harvested at 24° Brix. Selected key aroma compounds in Frontenac and Marquette wines were ethyl hexanoate, ethyl isobutyrate, ethyl octanoate, and ethyl butyrate. OAVs >1000 were reported for three aroma compounds that impart fruity aromas to the wines. This study provides evidence that aroma profiles in Frontenac wines can be influenced by timing of harvesting the berries at different Brix. Future research should focus on whether this is because of berry development or accumulation of aroma precursors and sugar due to late summer dehydration. Simultaneous chemical and sensory analyses can be useful for the understanding development of aroma profile perceptions for wines produced from cold-climate grapes.

The Chemical Reaction of Glutathione and trans-2-Hexenal in Grape Juice Media To Form Wine Aroma Precursors: The Impact of pH, Temperature, and Sulfur Dioxide.

The aldehyde 3-S-glutathionylhexanal is an intermediate which is produced during the formation of the wine aroma precursor 3-S-glutathionylhexanol, after the reaction of glutathione with trans-2-hexenal. This study was conducted to assess whether the chemical, as opposed to the enzymatic, production of 3-S-glutathionylhexanal could occur at a significant rate in grape juice. LC-MS/MS was used in low- and high-resolution modes, in combination with functional group derivatization, to identify and quantitate products. In comparison to cysteine, glutathione was found to induce less cyclized products on reaction with trans-2-alkanals and the glutathione-derived products were more reactive to hydrogen sulfite. The zero-order rates for 3-S-glutathionylhexanal formation in model grape juice were 1.08 ± 0.08 and 0.45 ± 0.05 mg/(L·day) glutathione equivalents at 25 and 13 °C, respectively, and the reaction rate increased 3-fold by increasing the pH from 3.2 to 3.8. 3-S-Glutathionylhexanal was detected in all five white grape juices examined. The concentration of the aldehyde could be increased by up to 10-fold after being released from hydrogen sulfite, demonstrating a potentially novel source for the production of varietal thiol aroma compounds in wine.

The effect of high power ultrasound on phenolic composition, chromatic characteristics, and aroma compounds of red wines

The effect of high power ultrasound on phenolic composition, chromatic characteristics, and aroma compounds of red wines

Dual solid-phase and stir bar sorptive extraction combined with gas chromatography-mass spectrometry analysis provides a suitable tool for assaying limonene-derived mint aroma compounds in red wine

A novel analytical method was developed for quantitative determination of eight limonene-derived monoterpenes responsible for the mint aroma in red wine. As these aromatic compounds are present at trace levels, a new dual extraction approach was proposed, combining solid-phase extraction (SPE) and stir bar sorptive extraction (SBSE), followed by gas chromatography-mass spectrometry analysis. The various parameters affecting the efficiency of extracting the analytes from wine samples in both the SPE and SBSE steps were first investigated, to determine the best compromise for the simultaneous analysis of the compounds studied. Following preliminary optimization of the dilution factor, phase ratio, and methanol content in the SBSE sample, cartridge sorbent mass, type of solvent, elution volume, and wine sample volume in the pre-concentration SPE step were studied. Highest response values were obtained when a 90 mL wine sample was extracted on a 500 mg SPE C18 cartridge and eluted with 1.5 mL methanol. The wine extract was then diluted in 10 mL water to obtain a final methanol content of 15% before the SBSE step. Good linearity, repeatability, reproducibility, accuracy and the required low detection and quantification limits were obtained under the conditions described, making this SPE-SBSE combination a suitable, powerful tool for routine analysis of the selected limonene-derived mint aroma compounds in large series of wine samples. Finally, the validated method was applied to 15 commercial red Bordeaux wines, aged from 3 to 23 years. Most of the compounds studied, present within the ng.L−1 range, were easily quantified for the first time in wine.

Analysis of aroma compounds of pitaya fruit wine

In order to analyze the volatile components in red pitaya fruit wine, the study using headspace solid phase microextractionand gas chromatography-mass spectrometry technology of pitaya fruit juice and wine aroma composition analysis comparison. Results showed that 55 volatile components were detected in red pitaya fruit wine, including 12 kinds of alcohol (18.16%), 18 kinds of esters (66.17%), 7 kinds of acids (5.94%), 11 kinds of alkanes (4.32%), one kind of aldehyde (0.09%), 2 kinds of olefins (0.09%) and 3 kinds of other volatile substances (0.23%). Relative contents among them bigger have 11 species, such as decanoic acid, ethyl ester (22.92%), respectively, diisoamylene (20.75%), octanoic acid, ethyl ester (17.73%), etc. The red pitaya fruit wine contained a lot of aroma components, which offer the products special aroma like brandy, rose and fruit.

Aroma modulation of Cabernet Gernischt dry red wine by optimal enzyme treatment strategy in winemaking

Cabernet Gernischt (CG) is a famous Chinese wine grape cultivar, the red wine of which is known for its green trait, especially when produced from grapes cultivated in regions with monsoon climate. To modify CG wine aroma, three enzyme preparations (H. uvarum extracellular enzyme, AR2000, and pectinase) were introduced in different winemaking stages with Saccharomyces cerevisiae. Free and bound aroma compounds in young wines were detected using headspace solid-phase micro-extraction and gas chromatography-mass spectrometry, and aroma characteristics were quantified by trained panelists. Results showed that simultaneous inoculation of enzymes and yeasts improved wine aroma. Partial least-squares regression revealed that the green trait was due mainly to varietal compounds, especially C6 compounds, and could be partly weakened by fermentative compounds. Moreover, H. uvarum enzyme treatments enriched the acid fruit note of CG wine by enhancing the synergistic effect of varietal volatiles and certain fermentative compounds, such as esters and phenylethyls.

Effect of the addition of branched-chain amino acids to non-limited nitrogen synthetic grape must on volatile compounds and global gene expression during alcoholic fermentation

Background and Aims The concentration and composition of nitrogen (N) in must is critical to yeast fermentation and aroma profiles in wine. We investigated the effect of adding branched-chain amino acids (BCAAs, including l-valine, l-leucine and l-isoleucine) to a non-limited N medium on the formation of aromatic compounds and on gene expression patterns of the wine yeast Saccharomyces cerevisiae. Methods and Results A synthetic N-sufficient must was supplemented with BCAAs and fermented with S. cerevisiae. The fermentation kinetics, aroma characteristics and yeast global gene expression in wine with addition of BCAAs were compared with that of the Control. Addition of BCAAs improved yeast growth and fermentation activity, increased the production of higher alcohols, medium-chain fatty acids and their corresponding esters (82, 34 and 49% increment compared to that of the Control, respectively). The comparative transcriptomic analysis revealed that 25 genes varied in their expression during fermentation with added BCAAs relative to that of the Control, which are mainly involved in yeast growth and proliferation (GIP1, DIT2, RCK1, SPO1 and MEK1) and transport of amino acids (GAP1). Conclusions An increase in BCAA transport ability and in yeast population is the main reason for achieving an increased concentration of volatile aroma compounds in wine with addition of BCAAs. Significance of the Study Our results suggest that adding BCAAs into N-sufficient must is still an efficient way to adjust wine's aromatic composition and improve aroma complexity.

Comparative Characterization of Aroma Compounds in Merlot Wine by LiChrolut-EN-Based Aroma Extract Dilution Analysis and Odor Activity Value

It has been challenging to select the best method to extract and analyze aroma-active compounds in wine due to high concentration of alcohols in the sample. The objectives of this study were to investigate the applicability of a LiChrolut-EN-based solid-phase extraction (SPE) for wine aroma extraction and to characterize the aroma-active compounds in Merlot wine. Volatile compounds in a Merlot wine were extracted with Lichrolut-EN SPE or liquid-liquid extraction (LLE) followed by solvent-assisted flavor evaporation (SAFE). Both extracts were used for aroma extract dilution analysis (AEDA). Selected aroma-active compounds were further quantitated and their odor activity values (OAV) were calculated. Both SPE and LLE extracts can be used for aroma extract dilution analysis. The odorants with high flavor dilution (FD ≥ 64) values in Merlot wine were ethyl 2-methylpropanoate, ethyl butanoate, ethyl 2-methylbutanoate, ethyl 3-methylbutanoate, ethyl hexanoate, ethyl octanoate, 3-methylbutyl acetate, 2/3-methyl-1-butanol, 2-phenylethanol, acetic acid, 2-methylpropanoic acid, butanoic acid, 3-methylbutanoic acid, hexanoic acid, β-damascenone, E-whiskeylactone, γ-nonalactone, 3-(methylthio) propanol, 4-hydroxy-2,5-dimethyl-3(2H)-furanone, 2-ethyl-4-hydroxy-5-methyl-3(2H)-furanone, sotolon, vanillin, guaiacol, and eugenol. Quantitative analysis and calculated odor activity value (OAV) suggested that ethyl butanoate, ethyl 2-methylbutanoate, ethyl hexanoate, 3-methylbutyl acetate, ethyl octanoate, ethyl acetate, 2/3-methyl-1-butanol, butanoic acid, 3-methylbutanoic acid, hexanoic acid, β-damascenone, and acetaldehyde could be the major contributors (OAV ≥ 5) to Merlot wine aroma. Lichrolut-EN SPE was generally comparable with LLE to obtain wine aroma compounds. SPE extract had higher flavor dilution values for esters, and lower for acids and some alcohols than LLE, which is advantageous to study aroma-active compounds in alcoholic beverages due to less interferences from alcohol and acid and improved chromatography. This study confirmed the applicability of LiChrolut-EN SPE as an alternative extraction method for wine aroma characterization to improve laboratory efficiency and minimize the usage of organic solvent.

Application of Volatile Compounds Analysis for Distinguishing between Red Wines from Poland and from Other European Countries

Authenticity and the geographical origin of wines are terms of great importance for consumers and producers. This work is focused on distinguishing between red wines from Poland and from other European countries, notably France, Italy and Spain. To achieve this goal, we determined aroma compounds in wines from different countries by headspace solid-phase microextraction/gas chromatography-mass spectrometry. The content of hexan-1-ol in Polish wines was significantly higher (about twice as high) than in French, Italian and Spanish wines. Linear discriminant analysis (LDA) showed that 3-(methylsulfanyl) propane-1-ol, hexan-1-ol, ethyl phenylacetate and ethyl 2-hydroxy-4-methylpentanoate were the most discriminant variables for distinguishing between wines from Poland and from other European countries. Hierarchical cluster analysis (HCA) revealed that Polish wines were separated thoroughly from the other wines based on ethyl phenylacetate, hexan-1-ol, ethyl 2-hydroxy-4-methylpentanoate, (E)-3-hexen-1-ol, 2-phenylethanol and 3-(methylsulfanyl)propan-1-ol, which is important for preventing possible frauds.

Indigenous yeasts perform alcoholic fermentation and produce aroma compounds in wine

The spontaneous alcoholic fermentations of Moscato Bianco and Welschriesling must were carried out to retrieve indigenous yeasts. We confirmed that those fermentations, conducted with non-Saccharomyces and indigenous Saccharomyces cerevisiae yeasts, can generate high amounts of aroma compounds in wines. Consequently, two of the S. cerevisiae isolates were randomly chosen and further examined in Welschriesling and Sauvignon Blanc must for their ability and efficiency in performing alcoholic fermentation. Alcoholic fermentation with a commercial yeast strain was carried out for comparison. Indigenous isolates showed acceptable fermentation ability and efficiency. Moreover, Sauvignon Blanc produced with indigenous isolates contained significantly higher amounts of 3-mercaptohexyl acetate, linalool, geraniol and 2-phenylethanol and a significantly lower amount of 3-mercaptohexan-1-ol. Differences in Welschriesling wine were less striking but in this case indigenous isolates produced lower amounts of 3-mercaptohexan-1-ol and α-terpineol. Taken together, our results confirm that a suitable aromatic profile of wine can be produced with indigenous S. cerevisiae strains.

The effect of watering frequency on the welfare quality of dairy cow

Wine aroma is an important index for wine quality evaluation. There are also many flavor substances, including esters, alcohols, acids, aldehydes, ketones, glycerin, sugars, amino acids, organic acids, phenolic compounds, and so on. They play important roles in wine sensory quality and flavor, characteristics such as acidity, color, bitter taste, convergence, clarifying degree, and so on. The existence of complex aroma compounds in wines, together with their concentration, their proportion, and the balance among them, leads to unique styles and characteristics of wines. In these compounds, each kind of aroma compound contributes to the wine flavor at a different grade, and additive effects, synergistic interaction, and separation and inhibition effects among them endow wine with complex and unique flavors. In this chapter, the types, extraction, isolation, and identification of flavor compounds in wine are introduced. Regarding beer, as a kind of food, flavor is a significant attribute. Beer flavor is studied to figure out consumption tendency and launch products catering to consumers' demands and desires. In the meantime, because of the complex mechanism of the fermentation process, flavor is used as an indicator to monitor beer fermentation and ensure the stability and quality of products. Among the various flavor components that exist in beer, more than 600 kinds are known and the thresholds of over 200 kinds have been determined. Furthermore, new flavor compounds will be generated during processing and subsequent storing, which have impacts on beer flavor. To some extent, the beer brewing process is the process of the synthesis, decomposition, and transformation of these flavor compounds. From the perspective of flavor, the properties, sources, and metabolic processes of alcohols, esters, carbonyl compounds, sulfides, diketones, and acids are introduced in this section.

The influence of hemodialysis on hemoglobin in dogs with acute renal injury

Wine aroma is an important index for wine quality evaluation. There are also many flavor substances, including esters, alcohols, acids, aldehydes, ketones, glycerin, sugars, amino acids, organic acids, phenolic compounds, and so on. They play important roles in wine sensory quality and flavor, characteristics such as acidity, color, bitter taste, convergence, clarifying degree, and so on. The existence of complex aroma compounds in wines, together with their concentration, their proportion, and the balance among them, leads to unique styles and characteristics of wines. In these compounds, each kind of aroma compound contributes to the wine flavor at a different grade, and additive effects, synergistic interaction, and separation and inhibition effects among them endow wine with complex and unique flavors. In this chapter, the types, extraction, isolation, and identification of flavor compounds in wine are introduced. Regarding beer, as a kind of food, flavor is a significant attribute. Beer flavor is studied to figure out consumption tendency and launch products catering to consumers' demands and desires. In the meantime, because of the complex mechanism of the fermentation process, flavor is used as an indicator to monitor beer fermentation and ensure the stability and quality of products. Among the various flavor components that exist in beer, more than 600 kinds are known and the thresholds of over 200 kinds have been determined. Furthermore, new flavor compounds will be generated during processing and subsequent storing, which have impacts on beer flavor. To some extent, the beer brewing process is the process of the synthesis, decomposition, and transformation of these flavor compounds. From the perspective of flavor, the properties, sources, and metabolic processes of alcohols, esters, carbonyl compounds, sulfides, diketones, and acids are introduced in this section.

The role of potent thiols in Chardonnay wine aroma

Background and Aims Polyfunctional thiols are key aroma compounds in many Sauvignon Blanc wines, but their role in other white cultivars is not clear. Methods and Results A survey of 106 commercial Australian Chardonnay wines found a high concentration of 3-mercaptohexan-1-ol, 3-mercaptohexyl acetate, benzyl mercaptan and 4-mercapto-4-methylpentan-2-one, with nearly all wines having a concentration of all compounds well above their reported sensory detection threshold, and some having a concentration comparable to that found in highly fruity Sauvignon Blanc wines. Wines were made on a research scale from a set of Chardonnay juices sourced from 16 vineyards across Australia. Sensory descriptive analysis combined with quantitative aroma volatile data revealed that several aroma and flavour attributes were related to the concentration of the thiols. Conclusions This study provided evidence that substantial flavour in Chardonnay can be contributed by these thiols. Additionally, consumer acceptance data showed that wines with a higher thiol concentration were liked by most consumers. Significance of the Study This study revealed the importance of polyfunctional thiols in Chardonnay wine.

Characterization of the Key Aroma Compounds in Chinese Syrah Wine by Gas Chromatography-Olfactometry-Mass Spectrometry and Aroma Reconstitution Studies.

The key aroma compounds and the organoleptic quality of two Chinese Syrah wines from the Yunnan Shangri-La region and Ningxia Helan mountain region were characterized. The most important eighty aroma-active compounds were identified by Gas Chromatography-Olfactometry. In both Syrah samples, ethyl 2-methylpropanoate, ethyl 3-methylbutanoate, 3-methylbutyl acetate, 2- and 3-methyl-1-butanol, ethyl hexanoate, ethyl octanoate, 2-phenethyl acetate, methional, 3-methylbutanoic acid, hexanoic acid, octanoic acid, β-damascenone, guaiacol, 2-phenylethanol, trans-whiskylactone, 4-ethylguaiacol, eugenol, 4-ethylphenol, and sotolon were detected to have the highest odor intensities. In the chemical analysis, 72 compounds were quantitated by Stir Bar Sorptive Extraction combined with Gas Chromatography Mass Spectrometry. Based on the Odor Activity Value (OAV), the aromas were reconstituted by combining aroma compounds in the synthetic wine, and sensory descriptive analysis was used to verify the chemical data. Fatty acid ethyl esters, acetate esters, and β-damascenone were found with higher OAVs in the more fruity-smelling sample of Helan Mountain rather than Shangri-La.

First identification and quantification of S-3-(hexan-1-ol)-γ-glutamyl-cysteine in grape must as a potential thiol precursor, using UPLC-MS/MS analysis and stable isotope dilution assay

Varietal thiols are key aroma compounds in wine issued from multiple and complex origins. Several precursor families have been identified in grapes and must and have been widely studied. But a large part of thiol origin still remains unknown. Thus, we only have an incomplete picture of thiol precursors and there is a lack of knowledge on pre-fermentative mechanisms that can impact their levels. Our study focused on the formal identification and the quantification of new varietal thiol precursors in must. First of all, we synthesized natural and labeled standards using an original multi-step strategy, then we developed and validated a UPLC-MS/MS method that allowed us to identify and quantify for the first time a dipeptide S-conjugate to 3MH, the γGluCys-3MH, in Sauvignon B. We observed the S-4-mercapto-4-methylpentan-2-one-l-cysteinyl-glycine (CysGly-4MMP) and S-4-mercapto-4-methylpentan-2-one-N-(l-γ-glutamyl)-l-cysteine (γGluCys-4MMP) but at too low concentration to be quantified.

Effects of sunlight exclusion on the profiles of monoterpene biosynthesis and accumulation in grape exocarp and mesocarp

Terpenes are important aroma compounds in table Muscat grape and wine, and their content in the berry can be affected by sunlight. The effects of sunlight exclusion on monoterpene profiles and relevant gene expression profiles in the exocarp and mesocarp of table Muscat grape ‘Jingxiangyu’ at different development stages were thoroughly surveyed by bagging pre-veraison clusters in special opaque boxes. The responses of monoterpenes to sunlight treatments varied in three types, representatively linalool, ocimene and geraniol. Linalool was the most sensitive compound to sunlight, whose biosynthesis was severely inhibited by sunlight exclusion and then was elevated by re-exposure. Ocimene and glycosylated geraniol showed a certain suppressive and stimulative responses to sunlight exclusion respectively. Further transcription analysis revealed that VvPNLinNer1, VvCSbOci, VvGT7 and VvGT14 genes were mainly responsible for monoterpene accumulation and sensitivity to sunlight. VvDXS2 and VvDXR genes were partially related to the differential accumulation of total terpenes under different sunlight treatments.

Comparative study of sodium bentonite and sodium-activated bentonite fining during white wine fermentation: its effect on protein content, protein stability, lees volume, and volatile compounds

In this work, we compare the effect of the addition during fermentation of both sodium bentonite and sodium-activated bentonite on the protein content, protein stability, lees volume, and aroma compounds of a Sauvignon blanc wine. Protein unstable Sauvignon blanc juices were vinified with or without bentonite added at three different stages: before fermentation, early during fermentation, and towards the end of fermentation. Different addition doses of bentonite were used (X, X − 0.1, X − 0.2 g/L) according to protein instability of the grape juice (X = 1.7 and 2.7 g/L to sodium bentonite and sodium-activated bentonite, respectively). The wines stabilized with sodium-activated bentonite presented a higher content of volatile compounds and a lower volume of lees were produced than those treated with sodium bentonite, an effect that was greater when the fining treatment was done before the start of the fermentation.

Volatile compounds in wild strawberry and their odorants of wild strawberry wines: Effects of different stages of fermentation

ABSTRACTWild strawberries are grown widely in southern Shaanxi (China), but information about their sensory and chemical characteristics is scant. In this work, exploratory research was conducted to correlate the results of instrumental analyses of the aroma compounds in wild strawberry wine and their sensory perception. Headspace solid-phase micro extraction (HS-SPME) was used for the pretreatment, and gas chromatography-mass spectrometry (GC-MS) was to analyze the aroma compounds. A total of 78 volatile compounds were identified, including 25 alcohols, 25 esters, four acids, five ketones, four aldehydes, nine terpenes, five phenols, and one styrene, but only 74 could be quantified. Odor activity values (OAVs) were determined for 21 odor-active compounds. Six were identified as the characteristic aroma substances for the wild strawberries from a principal component analysis (PCA) of the composition, in particular methyl 2-methylbutyrate, ethyl 2-methylbutyrate, ethyl 3-methylbutyrate, (E)-3-hexen-1-ol, 1-octen-3-ol, and phenylacetaldehyde. Sensory evaluation by a trained panel using descriptive analysis also revealed that sweetness was the main attribute in wild strawberry and its wines, and differences in varietal flavors were also observed. Wild strawberry wine is proved to exhibit a high quality of its fruit flavor, and thus winemaking is a performable practice for wild strawberry.

What is the expected impact of climate change on wine aroma compounds and their precursors in grape?

<p>The intrinsic quality of a wine is strongly linked with its volatile compound composition involved in the complexity of wine’s subtle flavor nuances. Those reminiscent of green pepper, herbaceous, blackcurrant, blackberry, figs or prunes are strongly linked with the maturity of the grapes. Nowadays it is well accepted that macroscopic effects of climate change modify the environmental conditions of grape growing at local scale in all the vineyards across the world. The expected effects on grape and wine production can be positive when they increase the maturity of the grapes, but when the conditions are too warm and too dry they induce opposite effects producing grapes and wines with a lower intrinsic quality. These effects were perceived in young wines but also in older wines kept several years in bottle.</p><p>In this article, we provide some examples of effects of climate change and growing conditions on grapevine and wine quality expressed as flavors and antioxidant composition. We also report some results associated with the incidence of grape growing conditions on white and red wine aging potential and on the composition of old wines.</p><p>Finally, we discuss the opportunities for vine growers and winemakers to manage the quality of their grapes and wines in this climate change context.<strong></strong></p>