Wine Aroma Compounds Research Articles

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

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.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.Finally, we discuss the opportunities for vine growers and winemakers to manage the quality of their grapes and wines in this climate change context.

The Impact of Wine Style and Sugar Addition in liqueur d’expedition (dosage) Solutions on Traditional Method Sparkling Wine Composition

The purpose of this study was to investigate the effect of wine style and cane sugar addition in the liqueur d’expedition (dosage) solution on volatile aroma compounds (VOCs) in traditional method sparkling wine. There were 24 bottles of each treatment produced. Treatments were sparkling wine zero dosage (ZD); NV sparkling wine + sugar (BS); unoaked still Chardonnay wine + sugar (UC); Pinot noir 2009 sparkling wine + sugar (PN); Niagara produced Brandy + sugar (B) and Icewine (IW). The control treatment in the sensory analysis was an oaked still Chardonnay wine + sugar (OC) because the zero-dosage wine was not suitable for a difference test that compared wines with sugar to one without. Standard wine chemical parameters were analysed before disgorging and after liqueur d’expedition was added and included; pH, titratable acidity (TA g/L), alcohol (v/v %), residual sugar (RS g/L), free and total SO2 and total phenolics (A.U.). Volatile aroma compounds (VOCs) analysed by Headspace Solid- Phase Micro-Extraction Gas Chromatography-Mass Spectrometry (HS-SPME-GC-MS) included two alcohols, and six ethyl esters. ZD wines had the highest foam height and highest dissolved oxygen level. Sugar affected VOC concentrations in all treatments at five weeks post-disgorging, but by 15 weeks after liqueur d’expedition addition, the wine with added sugar had similar VOC concentrations to the ZD wines. The type of wines used in the dosage solutions had more influence on VOC concentrations than sugar addition.

The glycosidic aroma precursors in wine: occurrence, characterization and potential biological applications

Wine aroma is defined as the cumulative effect of smell, taste and mouth-feel. Free and glycosidically bound aroma compounds (GBAC) were found in wine. The glycosidic aroma precursors are non-odorous. Most advances have been made in free aroma compounds from wine in recent decades. However, the glycosidically bound aroma compounds have received much less consideration than free aroma compounds. Acids and enzymes are responsible for transferring these glycosidic aroma precursors to aromatic compounds. This review provides an overview of recent developments in isolation, hydrolysis and characterization for glycosidic aroma precursors in wines, as well as their biological applications. It looks like that the GBAC had important biological applications, such as, genetic engineering, immobilization, aroma enhancement and biosynthesis. It will help to better understand the GBAC and free aroma compounds of wines.

Effect of L-isoleucine and L-phenylalanine Addition on Aroma Compound Formation During Longan Juice Fermentation by a Co-culture of Saccharomyces cerevisiae and Williopsis saturnus

Some amino acids are known to be precursors of aroma-active compounds produced by yeast metabolism. This study examined the effect of the addition of L-isoleucine and L-phenylalanine on the volatile profiles of longan wine fermented by a co-culture of Saccharomyces cerevisiae var. bayanus EC-1118 and Williopsis saturnus var. saturnus CBS254 inoculated at a ratio of 1:1 000 cfu/mL with the aim of enhancing longan wine aroma. Significantly higher concentrations of active amyl alcohol (2-methyl-1-butanol), 2-phenylethyl alcohol and their corresponding acetate esters were found in the longan wine with added L-isoleucine and L-phenylalanine respectively, compared with the control (without added amino acids). The biosynthesis of other volatile compounds was either similar or minimally different, although the formation of some acetate esters, such as isoamyl acetate, hexyl acetate and ethyl acetate, was decreased. These results suggest that the added amino acids play an important role in enhancing the production of targeted aroma compounds in longan wine fermented with mixed yeasts, and that the addition of selected amino acids can be a valuable tool to modulate the formation of aroma compounds in longan wine.

Impact of Amino Acid Addition on Aroma Compounds in Papaya Wine Fermented with Williopsis mrakii

The impact of amino acid addition on aroma compound formation in papaya wine fermented with yeast Williopsis saturnus var. mrakii NCYC2251 was studied. Time-course papaya juice fermentations were carried out using W. saturnus var. mrakii NCYC2251, with and without the addition of selected amino acids (L-leucine, L-isoleucine, L-valine and L-phenylalanine). Yeast growth and changes in sugars, °Brix, organic acids and pH were similar, regardless of amino acid addition. L-Leucine addition increased the production of isoamyl alcohol and some esters such as isoamyl acetate, isoamyl butyrate and isoamyl propionate, while L-isoleucine addition increased the production of active amyl alcohol and active amyl acetate. L-valine addition slightly increased the production of isobutyl alcohol and isobutyl acetate. L-phenylalanine addition increased the formation of 2-phenylethanol, 2-phenylethyl acetate and 2-phenylethyl butyrate, while decreasing the production of most other esters. This study suggests that papaya juice fermentation with W. saturnus var. mrakii NCYC2251 in conjunction with the addition of selected amino acid(s) can be an effective way to modulate the aroma of papaya wine.

Effect of Grapevine Age on the Aroma Compounds in ‘Beihong’ Wine

The main aim of this study was to determine the influence of grapevine age (3, 6 and 12 years) on the aroma compounds in ‘Beihong’ wine. Aroma compounds in wine were analyzed by solid-phase microextraction gas chromatography-mass spectrometry (SPME-GC/MS). Thirty-three (33) volatile compounds were identified and quantified. The majority of aroma compounds were esters (20) and the concentration of these totaled 90.63-92.82% (w/w) of the total aroma compounds; particularly, ethyl octanoate and ethyl decanoate. Through the descriptive analysis aroma profile for ‘Beihong’ wine, the highest aroma contribution was from the fruity and floral series. As the age of the grapevine increased, the concentrations of total volatiles and total odor activity values (OAVs) of the wines significantly increased (p < 0.001). This suggests that grapevine age could affect berry composition, enhance the content of wine aroma compounds and improve wine quality.

Correlations between Aroma Profiles and Sensory Characteristics of Red Wines by Using Partial Least Squares Regression Method

The aim of this study is to examine the effectiveness of Partial Least Squares Regression (PLSR) method in determing correlations between the aroma profiles and sensory characteristics of wines. A total of 45 volatile compounds in five different Chinese grape wines were identified and quantified by HS-SPME/GC-MS and 26 of them with OAV (odour activity value) ＞1. All aroma compounds with OAV＞1 were selected for evaluating the correlations between the aroma profiles and 12 sensory descriptors using PLSR and their ROC (Relative Odour Contribution). The results showed that ethyl decanoate, ethyl hexanoate, acetaldehyde, isoamyl acetate, hexanoic acid, 4-vinylguaiacol and geraniol were the major contributors to the desirable balanced aroma of muscat wine. Ethyl hexanoate, ethyl butyrate, isoamyl acetate, acetaldehyde, hexanoic acid, 3-methyl-1-butanol and octanoic acid were mainly responsible for the aroma of black beet wine and cabernet gernischt wine whereas ethyl tetradecanoate, neryl acetate and nerol were the particular aroma compounds in black beet wine and γ-butyrolactone, nerolidol and β-ionone were special aroma compounds in cabernet gernischt wine. Both PLSR and ROC are effective methods to demonstrate the correlations between the sensory characteristics of the analyzed wines and their aroma compositions.

Meta-Analysis of the Core Aroma Components of Grape and Wine Aroma.

Wine aroma strongly influences wine quality, yet its composition and its evolution during the winemaking process are poorly understood. Volatile compounds that constitute wine aroma are traditionally divided into three classes according to their origin: grape, fermentation, and maturation aroma. We challenge this view with meta-analysis and review of grape and wine volatiles and their precursors from 82 profiling experiments. We compiled a list of 141 common grape and wine volatiles and quantitatively compared 43 of them. Our work offers insight into complex relationships between biosynthesis of aroma in grapes and the changes during the winemaking process. Monoterpenes are one of the largest and most researched wine aroma compounds. We show that their diversity in wines is mainly due to the oxidative metabolism of linalool in grapes. Furthermore, we demonstrate that most of the linalool produced in grapes is converted to these oxidized derivatives.

Chemical and Sensory Evaluation of Silicone and Polylactic Acid-Based Remedial Treatments for Elevated Methoxypyrazine Levels in Wine.

Alkylmethoxypyrazines (MPs) are a class of compounds that can elicit undesirable aroma and flavor characteristics in wine, and resist remediation using traditional wine making approaches. MPs are grape-derived constituents as well as contaminants from Coccinellidae beetles present during wine processing; the latter eliciting an off-flavor referred to as ‘ladybug taint’. In this study we investigated the capacity of two plastic polymers—one silicone-based, the other polylactic acid-based—applied with varying surface areas to reduce concentrations of isopropylmethoxypyrazine (IPMP), sec-butylmethoxypyrazine (SBMP) and isobutylmethoxypyrazine (IBMP) in a Merlot wine using multi-dimensional gas chromatography coupled with mass spectrometry and headspace solid phase microextraction (SPME-MDGCMS). The impact of treatments on the sensory characteristics of the wine (descriptive analysis) and volatile aroma compounds (VOCs) (SPME-MDGCMS) was also investigated. Results showed substantial reductions for all of the target odorants: up to 38%, 44% and 39% for IPMP, SBMP and IBMP, respectively, for the silicone polymer, and up to 75%, 78% and 77% for IPMP, SBMP and IBMP, respectively, for the polylactic acid polymer. These polymers had no or minimal effect on VOCs at applications of 200 cm2/L for silicone or for all polylactic acid treatments. Sensory impacts were less clear, but generally showed minimal effect from the treatments. Taken overall, the data confirm the utility of both polylactic acid and silicone polymers in reducing elevated levels of grape-derived MPs, as well as potentially improving wine contaminated by ladybug taint.

Aroma characterization of predicate wines from Croatia

Predicate wines are sweet natural wines that in good years and appropriate conditions of ripening grapes on the vine, their degree of overripe and time of harvest, achieve a special quality. The aroma compounds of predicate wines from Croatia have not yet been studied. The predicate commercial wines (selected harvest wines and ice wines) of four different grape cultivars (‘Welschriesling’, ‘Kerner’, ‘Gewurztraminer’, ‘Chardonnay’) more than 10 years old were examined by GC–MS. Aroma compounds were extracted by solid-phase extraction. The results show that during ageing, sotolon and furfural concentrations are increased. Generally, higher concentrations of 1-octen-3-ol were noticed in selected harvest wines what may be connected with the metabolic activity of Botrytis cinerea. Linalool, β-damascenone, α-ionone, β-ionone, γ-nonalactone, sotolon, cis-rose oxide and 1-octen-3-ol had the greatest contribution to the overall aroma composition (odour activity value OAV ˃1). These results increase the understanding of aroma composition and the influence of ageing on selected harvest white wines and ice wines.

Distribution of Rotundone and Possible Translocation of Related Compounds Amongst Grapevine Tissues in Vitis vinifera L. cv. Shiraz.

Rotundone is an attractive wine aroma compound, especially important for cool climate Shiraz. Its presence in wine is mainly from the grape skin, but can also be found in non-grape tissues, such as leaves and stems. Whether rotundone is produced independently within different grapevine tissues or transported amongst non-grape tissues and grape berries remains unclear. The current study investigated the distribution of this compound in different vine tissues during development and studied the most likely mode of rotundone translocation—via phloem—using stable isotope feeding. In addition, local production of rotundone induced by herbivore feeding was assessed. Results showed that rotundone was firstly detected in the petioles and peduncles/rachises within the development of Vitis vinifera L. cv. Shiraz. Different grapevine tissues had a similar pattern of rotundone production at different grape developmental stages. In the individual vine shoots, non-grape tissues contained higher concentrations and amounts of rotundone compared to berries, which showed that non-grape tissues were the larger pool of rotundone within the plant. This study confirmed the local production of rotundone in individual tissues and ruled out the possibility of phloem translocation of rotundone between different tissues. In addition, other terpenes, including one monoterpenoid (geraniol) and six sesquiterpenes (clovene, α-ylangene, β-copaene, α-muurolene, δ-cadinene, and cis/trans-calamenene) were, for the first time, detected in the ethylenediaminetetraacetic acid-facilitated petiole phloem exudates, with their originality unconfirmed. Unlike other herbivore-induced terpenes, herbivorous activity had limited influences on the concentration of rotundone in grapevine leaves.

Small amounts of charcoal during fermentation reduce fungicide residues without penalising white wine aroma compounds and colour

Background and Aims The safety of foods and beverages is a prerequisite for consumers. The aim of this study is to check whether a low concentration of pesticide residues can be further reduced with the addition of a low dose of charcoal during white fermentation. Methods and Results Thirteen fungicides, boscalid, cyprodinil, fludioxonil, fenhexamide, pyrimethanil, cyazofamid, dimethomorph, fluopicolide, iprovalicarb, metrafenone, penconazole, spiroxamine and trifloxystrobin, were added together to five well-clarified and stabilised juices to reach a final fungicide concentration in juice slightly higher than that observed in bottled wines. Juices were fermented with two types of charcoal, both added at 20 and 50 mg/L. The course of fermentation was monitored, and the concentration of residual fungicides and of fermentative aromas was analysed by ultra-high performance liquid chromatography-MS/MS and GC-flame ionisation detector, respectively. Conclusions Charcoal removed up to 130 µg/L of fungicides. Compared with the control wines, those fermented with charcoal had 30–80% less fungicides. Only iprovalicarb was not significantly reduced. Aroma composition was not affected. Significance of the Study Low doses of charcoal added during fermentation can positively contribute to wine safety without penalising aroma and colour.

Understanding the Constitutive and Induced Biosynthesis of Mono- and Sesquiterpenes in Grapes (Vitis vinifera): A Key to Unlocking the Biochemical Secrets of Unique Grape Aroma Profiles.

The present review integrates current knowledge on mono- and sesquiterpenes in grapes with a special focus on biochemical and physiological aspects. Recent research has impressively shown the prominence of terpenoid metabolism in grapevine (Vitis sp). The 69 putatively functional mono- and sesquiterpene synthases that were identified by the analysis of the updated 12-fold sequencing and assembly of the grapevine genome deliver the scaffolds for structural diversity and display a surprising expansion of the terpene synthase (TPS) gene family in grapevine when compared to other plants like Arabidopsis thaliana (32 TPS). While monoterpenes occur as highly functionalized compounds and are stored as their corresponding glycoconjugates in berry tissues, sesquiterpenes are mainly present as unsaturated hydrocarbons and accumulate in the epicuticular wax layer of intact berries. Interestingly, both groups of terpenes appear to be involved as volatile organic compounds in plant defense and their biosynthesis is enhanced via the jasmonic acid signaling pathway. These novel aspects will help to understand how environmental cues affect the genes and enzymes of various metabolic pathways of relevant wine aroma compounds with numerous links to enology and wine flavor chemistry.

Effects of new Torulaspora delbrueckii killer yeasts on the must fermentation kinetics and aroma compounds of white table wine

Torulaspora delbrueckii is becoming widely recommended for improving some specific characteristics of wines. However, its impact on wine quality is still far from satisfactory at the winery level, mostly because it is easily replaced by Saccharomyces cerevisiae-like yeasts during must fermentation. New T. delbrueckii killer strains were here isolated and selected for winemaking. They killed S. cerevisiae yeasts and were able to dominate and complete the fermentation of sterile grape must. Sequential yeast inoculation of non-sterile white must with T. delbrueckii followed by S. cerevisiae did not ensure T. delbrueckii dominance or wine quality improvement. Only a single initial must inoculation at high cell concentrations allowed the T. delbrueckii killer strains to dominate and complete the must fermentation to reach above 11% ethanol, but not the non-killer strains. None of the wines underwent malolactic fermentation as long as the must had low turbidity and pH. Although no statistically significant differences were found in the wine quality score, the S. cerevisiae-dominated wines were preferred over the T. delbrueckii-dominated ones because the former had high-intensity fresh fruit aromas while the latter had lower intensity, but nevertheless nice and unusual dried fruit/pastry aromas. Except for ethyl propanoate and 3-ethoxy-1-propanol, which were more abundant in the T. delbrueckii–dominated wines, most of the compounds with fresh fruit odor descriptors, including those with the greatest odor activity values (isoamyl acetate, ethyl hexanoate, and ethyl octanoate), were more abundant in the S. cerevisiae–dominated wines. The low relative concentrations of these fruity compounds made it possible to detect in the T. delbrueckii–dominated wines the low-relative-concentration compounds with dried fruit and pastry odors. An example was γ-ethoxy-butyrolactone which was significantly more abundant in these wines than in those dominated by S. cerevisiae.

Effects of Fermentation Temperature on Key Aroma Compounds and Sensory Properties of Apple Wine

Fermentation temperature strongly affects yeast metabolism during apple wine making and thus aromatic and quality profiles. In this study, the temperature effect during apple wine making on both the key aroma compounds and sensory properties of apple wine were investigated. The concentration of nine key aroma compounds (ethyl acetate, isobutyl acetate, isopentylacetate, ethyl caprylate, ethyl 4-hydroxybutanoate, isobutylalcohol, isopentylalcohol, 3-methylthio-1-propanol, and benzeneethanol) in apple wine significantly increased with the increase of fermentation temperature from 17 to 20 °C, and then eight out of the nine key aroma compounds with an exception of ethyl 4-hydroxybutanoate, decreased when the temperature goes up 20 to 26 °C. Sensory analysis showed that the apple wine fermented at 20 °C had the highest acceptance for consumers. Fermentation at the temperature of 20 °C was therefore considered to be the most suitable condition using the selected yeast strain (Saccharomyces cerevisiae AP05) for apple wine making. Changes in the fermentation temperature can considerably affect the production of key aroma compounds and sensory profiles of apple wine. These results could help apple wine producers make better quality production for consumers at the optimal fermentation temperature.

Identification and Aroma Impact of Volatile Terpenes in Moutai Liquor

Terpenes are very important impact aroma compounds in wines, and we discovered some trace volatile terpenes in Chinese liquors in this study. The volatile compounds in Kweichow Moutai liquor (Maotai) were enriched and isolated by liquid–liquid extraction and further separated by silica gel normal phase chromatography, then investigated by gas chromatography–olfactometry and gas chromatography–mass spectrometry. A total of 55 terpenes were finally identified in Moutai liquor by mass spectrum data from NIST11 a.L and wiley7n.L mass-spectral library, retention indices, and authentic standards. A majority of terpenes were reported in Chinese liquors for the first time. A headspace–solid phase microextraction coupled with gas chromatography–mass spectrometry was developed to determine terpenes in Moutai liquor and other aroma-type Chinese liquors. According to the gas chromatography–olfactometry and odor activity values analysis, terpenes were the important aroma compounds in Moutai liquor which led the liquor more elegant and delicate.

Quantitative determination of five hydroxy acids, precursors of relevant wine aroma compounds in wine and other alcoholic beverages.

A method for the quantitative determination of 2-hydroxy-2-methylbutanoic (2OH2MB), 2-hydroxy-3-methylbutanoic (2OH3MB), 3-hydroxy-3-methylbutanoic (3OH3MB), 2-hydroxy-4-methylpentanoic (2OH4MP) and 3-hydroxybutanoic (3OHB) acids has been optimized, validated and applied to a set of wines and other alcoholic beverages. The analytes were preconcentrated in a solid phase extraction cartridge and derivatized with 2,3,4,5,6-pentafluorobenzyl bromide at room temperature for 30min, followed by GC-MS analysis. Detection limits were between 0.5 and 29μgL(-1), and linearity was maintained up to 3 or 12mgL(-1), depending on the analyte. Recovery values were between 85 and 106%, and reproducibility was better than 12% RSD in most cases. The first specific study of these analytes in wine and other alcoholic beverages is herein reported. Concentrations ranged from the method detection limits to 7820, 519, 8510, 3470 and 2500μgL(-1) for 2OH2MB, 2OH3MB, 3OH3MB, 2OH4MP and 3OHB, respectively, which may have relevant sensory effects. These products were not found in distillates (except 3OHB) but were all present in beer. 2OH2MB, 3OH3MB and 3OHB were found in unfermented grape derivatives. Sherry wines had the highest levels of all except for 3OHB.

Molecular cloning and characterization of UDP-glucose: furaneol glucosyltransferase gene from grapevine cultivar Muscat Bailey A (Vitis labrusca × V. vinifera).

2,5-Dimethyl-4-hydroxy-3(2H)-furanone (furaneol) is an important aroma compound in fruits, such as pineapple and strawberry, and is reported to contribute to the strawberry-like note in some wines. Several grapevine species are used in winemaking, and furaneol is one of the characteristic aroma compounds in wines made from American grape (Vitis labrusca) and its hybrid grape. Furaneol glucoside was recently isolated as an important furaneol derivative from the hybrid grapevine cultivar, Muscat Bailey A (V. labrusca × V. vinifera), and this was followed by its isolation from some fruits such as strawberry and tomato. Furaneol glucoside is a significant 'aroma precursor of wine' because furaneol is liberated from it during alcoholic fermentation. In this study, a glucosyltransferase gene from Muscat Bailey A (UGT85K14), which is responsible for the glucosylation of furaneol was identified. UGT85K14 was expressed in the representative grape cultivars regardless of species, indicating that furaneol glucoside content is regulated by the biosynthesis of furaneol. On the other hand, furaneol glucoside content in Muscat Bailey A berry during maturation might be controlled by the expression of UGT85K14 along with the biosynthesis of furaneol. Recombinant UGT85K14 expressed in Escherichia coli is able to transfer a glucose moiety from UDP-glucose to the hydroxy group of furaneol, indicating that this gene might be UDP-glucose: furaneol glucosyltransferase in Muscat Bailey A.

Comparison between aroma compounds in wines from four Vitis vinifera grape varieties grown in different shoot positions

The aroma characteristics of wines from four Vitis vinifera grape varieties (‘Cabernet sauvignon’, ‘Merlot’, ‘Chardonnay’, and ‘Italian Riesling’) grown in three shoot positions were evaluated by HS-SPME-GC/MS. In this study, the numerous significant differences found in most of the aromatic compounds influence of different shoot positions on the quality of wine. The results showed that the middle shoot position increased significantly the aroma concentration in the majority of wines investigated. The volatile components showing the greatest differences in the wines of different cultivars were aldehydes and terpenes. 8 and 11 compounds were found and quantified (D AVs>1) in the two red wines and white wines at concentrations higher than their corresponding odor thresholds, respectively; and therefore they significantly contributed to the wine aromas. According to their DAVs, fruity, floral, cheese and fatty aroma strongly influenced the characteristics of the four monovarietal wines, while the two white wines showed the green and fresh aroma characteristics. These results are related to the different microclimate of the canopies of the different shoot positions and varieties. They suggest that proper elevating the fruiting zones could improve the accumulation of aroma compounds in wines from the different varieties. Dn the other hand, grapevines trained to systems with uniform fruiting zones could improve the quality of wine.

Determination of Wine Aroma Compounds by Head Space “In Tube Extraction” Technique and Gas Chromatography (HS-ITEX-GC/MS)

This study investigates the influence of vintage on the aroma compounds of white wine Episcopal from vineyard Ciumbrud, located in central Transylvania, by a non-destructive head space in tube extraction technique in tandem with GC-MS. The samples selected for analysis come from three consecutive years (2009, 2010 and 2011) from Episcopal assortment, a high quality wine obtained by blending three types of wine varieties: Sauvignon Blanc, Traminer and Pinot Gris. The results reflect the compositional similarities but also the influence of vintage on the composition of wine aroma compounds. Results showed significant similarities between the composition of major compounds, 2-methyl-1-butanol, butanoic acid ethyl ester, hexanoic acid ethyl ester, octanoic acid ethyl ester, which together account for over 50% of the compounds identified. Significant differences appear both on the number of identified compounds in wine harvest 2010 compared to the other two years as well as through differences in concentration of two compounds: 3-methyl-butanol and 2,4-hexadienoic acid ethyl ester.