Grenache Wines Research Articles

The Impact of Fermentation Temperature and Cap Management on Selected Volatile Compounds and Temporal Sensory Characteristics of Grenache Wines from the Central Coast of California.

Grenache wines from the Central Coast of California were subjected to different alcoholic fermentation temperature regimes (Cold, Cold/Hot, Hot) and cap management protocols, namely, punch down (PD), or no punch down (No PD), to determine the effect of these practices on the color, aroma, and the retronasal and mouthfeel sensory characteristics of the resulting wines. Descriptive analysis (n = 8, line scale rating 0-15) results indicated that the combination of a hot fermentation temperature and no punch downs led to a significantly higher intensity in perceived color saturation (7.89) and purple hue (8.62). A two-way analysis of variance (ANOVA) showed that cap management was significantly more impactful on the perception of orthonasal aromas than fermentation temperature. The reduction aroma was significantly higher in No PD wines (5.02) compared to PD wines (3.50), while rose and hot aromas had significantly higher intensity perception for PD wines (5.18, 6.80) than for No PD wines (6.80, 6.14). Conversely, analysis of selected volatile compounds indicated that fermentation temperature was more impactful than cap management regime. Cold/Hot wines had higher concentrations of important esters such as ethyl hexanoate (650 µg/L) and isoamyl acetate (992 µg/L). Cold wines had a higher concentration of β-damascenone (0.719 µg/L). TCATA evaluation (n = 8) indicated that Cold/Hot PD wines had a significantly higher citation proportion of fruit flavor (1.0) and velvet astringency perception (0.80) without significant reduction flavors. Finally, the present study represents a contribution with the main volatile compounds (e.g., β-damascenone and esters in the Cold and Cold/Hot fermented wines, respectively; hexanol in PD wines, which may be potentially responsible for a hot mouthfeel), and sensory characteristics (red fruit, tropical fruit, white pepper, and rose) of Grenache wines grown in the Mediterranean climate of the Central Coast of California.

Phenolic and colour characteristics of must and wine obtained from red grapes treated by pulsed electric fields. Efficacy of PEF to reduce maceration time in elaboration of red wines

Pulsed electric fields effect was studied on the physico-chemical and general phenolic composition as colour characteristics and stilbene content in must and wine. For this purpose, a continuous pulsed electric fields equipment was used to treat three red grape varieties of DOCa Rioja. Graciano, Tempranillo and Grenache wines from these grapes were elaborated with different maceration times, 2 days in the untreated sample (control) and the PEF-treated sample (PEF), and normal maceration time in another untreated sample (control-NM). Parameters as colour intensity, anthocyanin content, total polyphenol index and tannin content showed no differences between the PEF sample with 2 days of maceration and the control-NM sample, except in the case of Tempranillo wines. Total stilbenes, trans-resveratrol and trans-piceid of Graciano wines elaborated from PEF samples showed a higher concentration than the control wines. Alternatively, PEF wines and control-NM wines showed no differences between them. Tempranillo variety wines presented no differences between the three types of samples. In the Grenache variety, only trans-piceid levels showed differences between control and PEF wines. Moreover, relationship between must and wine characteristics was evaluated and compared between different samples. The trend lines obtained for the CI, TPI and AC parameters for samples of Graciano, Tempranillo and Garnacha indicate that the initial content of compounds extracted significantly affected the days of maceration necessary to obtain the appropriate wine. The results obtained increase the knowledge of pulsed electric fields as a technology available for use in the winery to elaborate red wines with reduced maceration time.

Isolation and Characterization of High-Ethanol-Tolerance Lactic Acid Bacteria from Australian Wine.

Lactic acid bacteria are very important in winemaking. In this study, 108 lactic acid bacteria isolates were obtained from high-ethanol-content (~17% (v/v)) Grenache wines during uninoculated malolactic fermentation (MLF). The 16S rRNA and species-specific PCR showed that 104 of these were Oenococcus oeni, three were Lactobacillus hilgardii, and one was Staphylococcus pasteuri. AFLP of HindIII and MseI digests of the genomic DNA of the O. oeni strains was developed for the first time to discriminate the strains. The results showed that the method was a suitable technique for discriminating the O. oeni strains. Based on the cluster analysis, nine O. oeni strains were chosen for inclusion in an ethanol tolerance assay involving monitoring of optical density (ABS600nm) and viable plating. Several O. oeni strains (G63, G46, G71, G39) survived and grew well in MRS-AJ with 17% (v/v) ethanol, while the commercial O. oeni reference strain did not. Strain G63 could also survive and grow for 168 h after inoculation in MRS-AJ medium with 19% (v/v) ethanol. These results suggest that O. oeni G63, G46, G71, and G39 could potentially be used as MLF starters for high-ethanol-content wines. All three L. hilgardii strains could survive and grow in MRS-AJ with 19% (v/v) ethanol, perhaps also indicating their suitability as next-generation MLF starter cultures.

Do Non-Saccharomyces Yeasts Work Equally with Three Different Red Grape Varieties?

The present study aimed to investigate the oenological changes induced by non-Saccharomyces yeasts in three red grape varieties from the Rioja Qualified Designation of Origin. Pilot plants fermentation of three different varieties, were conducted following early inoculations with Metschnikowia pulcherrima and with mixed inoculum of Lachancea thermotolerans-Torulaspora delbrueckii from La Rioja and compared to a wine inoculated with Saccharomyces cerevisiae. The microbiological and physicochemical characteristics of vinifications were analysed. Results showed that most of the variations due to inoculation strategies were observed in Tempranillo just after the alcoholic fermentation, probably because of the better adaptation of the inocula to the must’s oenological properties. Finally, after the malolactic fermentation the inoculation with the mix of Lachancea thermotolerans and Torulaspora delbrueckii caused more changes in Tempranillo and Grenache wines while the early inoculation with Metschnikowia pulcherrima had more effects on Grenache wines. Therefore, the study was aimed to identify the fermentation effects of each inoculation strategy by using different non-Saccharomyces yeasts and different grape varieties.

Volatome finger printing of red wines made from grapes grown under tropical conditions of India using thermal-desorption gas chromatography-mass spectrometry (TD-GC/MS).

The current study evaluated the key characters of aroma composition in diversified red wines (Cinsaut, Grenache, Cabernet Franc, Petit Verdot, Cabernet Sauvignon, Nielluccio, Tempranillo, Syrah, Merlot and Caladoc). Out of hundreds of volatile compounds 64 compounds were considered for study. Different groups consisting of fatty acids, volatile alcohols, aldehydes, esters, volatile phenols and terpenes were analysed using gas chromatography mass spectrometry coupled with thermal desorption (TD-GC-MS). Among all these diversified classes, alcohols were found as the most dominant group followed by esters and acids whereas aldehydes, phenols and terpenes were found to be minor compounds. Among the varieties, Nielluccio wine recorded highest concentration of total volatile compounds (191.53mg/L) while, it was least in Caladoc wines (15.45mg/L). The principal component analysis clearly differentiated Grenache wines based on their relationships between scores and their aroma composition followed by Nielluccio and Cinsuat wines. Out of sixty four compounds, only six aromatic compounds viz. butanediol, isoamyl actate, γ-Terpene, butanol, acetic acid and furfural have satisfying aroma descriptors with floral and fruity nuances and contribute to differentiate the Grenache wines from other varieties which have similar scores in PC1 analysis. The cluster analysis also suggested that the wines in the same group (Cinsaut, Tempranillo and Syrah), (Cabernet Franc, Cabernet Sauvignon, Caladoc and Merlot) and (Nielluccio and Petit Verdot) had similar aroma characterization. Grenache wines were well differentiated from the sub group formed by other red varieties.

Effects of vineyard ‘potential’ and grape maturation on the aroma-volatile profile of Grenache wines

Background and aims: Wine is a beverage characterized by its pleasant aromatic features. These sensory notes are determined by the specific concentrations of odorous chemical compounds in each wine. Many of these aroma compounds arise directly or indirectly from the grapes, and their formation is affected by both grape metabolism and the viticultural ecosystem. Two studies were done with the 2015 vintage of Vitis vinifera L. cv. Grenache in Denominación Origen Somontano, a wine region of northern Aragon, Spain. In one study, we analysed wine from vineyards with different potentials: high potential, defined by balanced yield and high exposed leaf area (surface foliaire exposée, SFE, expressed in square metres) relative to production (P, expressed as kilograms of grapes) (i.e. high SFE:P ratio); and low potential, defined by unbalanced yield and low SFE:P ratio. In the other study, we analysed wine produced from grapes harvested at different times and therefore at different stages of ripening. The aim was to determine the effects of these variables on the aromatic compound profile of the wines.
 Methods and results: Concentrations of major aroma compounds were determined by gas chromatography (GC) with flame ionization detection, those of minor and trace aroma compounds by GC–mass spectrometry (MS), and those of pyrazines by thermal desorption–GC coupled with GC–MS. In the first study, wines from high-potential vineyards had higher concentrations of some compounds, such as esters of fermentative origin (isoamyl acetate, ethyl lactate and diethyl succinate), esters of varietal origin (ethyl dihydrocinnamate, methyl vanillate and ethyl vanillate), and terpenols (linalool and geraniol). In contrast, wines from low-potential vineyards had higher concentrations of 3-isopropyl-2-methoxypyrazine, γ-nonalactone and volatile phenols. In the second study, concentrations of varietal compounds such as rotundone and linalool increased with extended maturation. Furthermore, as ripening progressed, the ester to acid ratio for linear fatty acid ethyl esters generally increased while that for branched fatty acid ethyl esters tended to decrease. Acetaldehyde concentration was decreased in wines produced from grapes harvested at the latest date, a result that may be related to increased polyphenol content.Conclusions: The results of these studies provide an approximation of how the aromatic compound profile of a Grenache wine may differ between vineyards with different characteristics.Significance and impact of the study: We suggest explanations for these differences, which may guide the choice of harvest date.

Influence of grape maturity and prefermentative cluster treatment of the Grenache cultivar on wine composition and quality

<p>This work studied how different grape maturity levels and cluster treatments affect the color and phenolic composition of Grenache wines. Specifically, five treatments were undertaken at a microvinification scale for three maturity levels : Control (destemmed and crushed grapes), Whole Berry, Whole Cluster, Crushed Cluster and Submerged Cap. The first three treatments were also reproduced with large-scale wine fermentation in oak barrels but only with well-ripened grapes. The results indicated that the total polyphenol index (TPI), anthocyanin and proanthocyanidin concentrations, as well as the mean degree of polymerization were higher in all the treatments when the grapes were riper. Submerged Cap generated maximum color and polyphenolic extraction at the three maturity levels. Whole Berry wines were the most similar to the controls. The presence of stems (Crushed Cluster and Whole Cluster treatments) produced wines with a significantly higher pH at all maturity levels and with lower color intensity when the grapes were less ripe. The presence of stems also significantly increased the TPI in almost all cases.</p>

Changes of Phenolic Acids During Aging of Organic Wines

Grapes (Vitis vinifera L. origin var: Carignane, Cabernet Sauvignon, Merlot, Grenache, Columbard, and Semillon) were cultivated and processed according to accepted organic agriculture and organic wine techniques. Aged wines (5 years) were evaluated for changes of their phenolic acids. The highest reduction of gallic acid concentrations were determined in Cabernet Sauvignon (24.36 mg/L) and Carignane (16.00 mg/L) wines. The quantities of p-hydroxybenzoic acid decreased mostly in Carignane (22.47 mg/L) and Columbard (20.84 mg/L) wines. The decreases of syringic acid were dominant in Cabernet Sauvignon (2.34 mg/L) and Carignane (1.69 mg/L) wines. In the case of ferulic acid, the highest reduction was determined in Cabernet Sauvignon (3.97 mg/L) wines. The decreases of p-coumaric acid contents were the same and mostly in Merlot (1.06 mg/L) and Grenache (1.035 mg/L) wines. The principal component analyses results demonstrated the relations among aged wines produced from different grape varieties and their phenolic acids. The distribution of data was accumulated into two groups. The first group included total phenols, gallic acid, p-hydroxybenzoic acid, syringic acid, p-coumaric acid, and Merlot/Carignane/Grenache wines. The second one included ferulic acid and Cabernet Sauvignon wine.

Impact of Using New Commercial Glutathione Enriched Inactive Dry Yeast Oenological Preparations on the Aroma and Sensory Properties of Wines

The effect of the addition of a commercial enriched glutathione inactive dry yeast oenological preparation in the volatile and sensory properties of industrially manufactured rosé Grenache wines was evaluated during their shelf-life. In addition, triangle tests were performed at different times during wine aging (among 1 and 9 months) to determine the sensory differences between wines with and without glutathione inactive dry yeast preparations. Descriptive sensory analysis with a trained panel was carried out when sensory differences in the triangle test were noticed. In addition, consumer tests were performed in order to investigate consumers’ acceptability of wines. Results revealed significant sensory differences between control and glutathione inactive dry yeast wines after 9 months of aging. At that time, glutathione inactive dry yeast wines were more intense in fruity aromas (strawberry, banana) and less intense in yeast notes than control wine. The impact of the glutathione inactive dry yeast in the aroma might be the consequence of different effects that these preparations could induce in wine composition: modification of yeast byproducts during fermentation, release of volatile compounds from inactive dry yeast, interaction of wine volatile compounds with yeast macromolecules from inactive dry yeast and a possible antioxidant effect of the glutathione released by the inactive dry yeast preparation on some specific volatile compounds.

Effect of Cluster Thinning and Prohexadione Calcium Applications on Phenolic Composition and Sensory Properties of Red Wines

The overall objective of this study was to investigate the effect of manual cluster thinning (CT) and the application of the growth regulator Prohexadione calcium (ProCa) on the phenolic composition and the sensory profile of Tempranillo and Grenache wines produced from treated vines in La Rioja (Spain). ProCa was applied at preblooming and CT was carried out at veraison in two consecutive years. Different physicochemical parameters and analyses of phenolic compounds were carried out in control, CT and ProCa grapes and wines and wine sensory was performed. Thinning treatments decreased crop yield, besides ProCa application reduced berry size, and berry weight. Color and phenolic composition of Grenache and Tempranillo wines in general were affected by thinning treatments, with an increase in anthocyanin, flavanol and flavonol concentrations. In sensory analysis, wines obtained from thinned vines presented higher values for several aromatic (e.g., white and yellow fruits, fresh flowers) and taste attributes (i.e., astringency, bitternes, persistence). CT and ProCa treatments resulted in an improvement in wine quality. In general, similar results in phenolic composition, sensory properties and quality of wines were obtained by manual and chemical cluster thinning. ProCa as a growth regulator may be an option for a quality vitiviniculture.

Effect of using glutathione-enriched inactive dry yeast preparations on the phenolic composition of rosé Grenache wines during winemaking

<p style="text-align: justify;"><strong>Aim</strong>: To know the effect of the addition of a commercial glutathioneenriched Inactive Dry Yeast (G-IDY) oenological preparation on the <strong>phenolic profile and colour parameters of rosé Grenache wines.</strong></p><p style="text-align: justify;"><strong>Methods and results</strong>: A Control wine (Cont-W) and a wine with the GIDY preparation (G-IDY-W) were industrially manufactured. The evolution of the phenolic composition (anthocyanins and non-anthocyanins) and colour of both types of wines was evaluated during winemaking and their shelf-life (after 1, 2, 3 and 9 months of bottle aging). Results revealed that wines manufactured with the G-IDY preparation showed differences in both their phenolic composition and colour characteristics with respect to the control wines, particularly after 9 months of aging. These differences were more evident in the anthocyanin than in the non-anthocyanin compounds.</p><p style="text-align: justify;"><strong>Conclusions</strong>: The G-IDY wines showed a greater decrease of the anthocyanins from grape origin, probably due to the formation of anthocyanin-polysaccharide complexes, and a higher concentration of some anthocyanin-derived pigments. These changes can be related to the slower colour evolution determined in wines produced using G-IDY preparations.</p><p style="text-align: justify;"><strong>Significance and impact of the study</strong>: The addition of the G-IDY preparation during winemaking modifies the anthocyanin composition of the resulting wines, which seems to provoke a slower colour evolution during their shelf-life.</p>

Impact of post-bottling oxygen exposure on the sensory characteristics and phenolic composition of Grenache rosé wines

The impact of moderate oxygen exposure on the post bottling evolution of two Grenache rosé wines has been investigated. Different oxygen transfer rate (OTR) conditions were ensured by using synthetic closures with controlled oxygen permeability and storage under controlled atmosphere. Phenolic composition was determined, at bottling (T0) and after 10months of ageing (T10), by reverse-phase HPLC-DAD–MS analysis, performed directly on the wines and after phloroglucinolysis for proanthocyanidins. Colour was evaluated by UV–vis spectrophotometry and tristimulus colourimetry. Descriptive sensory analysis was carried out by a trained panel. Correlations were established between sensory analysis and colour, polyphenolic and enological measurements. At bottling, major phenolic compounds, in both rosé wines, were hydroxycinnamic acids, followed by anthocyanins and lower amounts of flavanols. After 10months of ageing, a loss of sulphites, native anthocyanins and flavanyl-anthocyanin adducts, an accumulation of phenyl-pyranoanthocyanins, and an increase of the colour intensity were observed. All these changes were enhanced under higher OTR conditions, especially in the wine containing initially higher levels of phenolic compounds. The higher OTR wines were also perceived as more floral and fruity and less animal than those stored under lower oxygen exposure, in agreement with previous observations on red Grenache wines.

Role of Glycosidic Aroma Precursors on the odorant profiles of Grenache noir and Syrah Wines from the Rhone valley. Part 1: sensory study

<p style="text-align: justify;"><strong>Aims</strong>: The aim of this study was to demonstrate the impact of the volatile compounds, arising from glycosidic precursors contained in the berries of Vitis vinifera L.cv Syrah and Grenache noir varieties, on wine aromas from these varieties.</p><p style="text-align: justify;"><strong>Methods and results</strong>: The sensory analysis was used to compare Grenache noir and Syrah wines. The role played by the glycosidic precursors on the future odorant profile of the wines from both varieties was demonstrated in an experiment by increasing their natural content in glycosides. Then, odorant compounds were generated by aging treatments, heating at 45 °C for 3 weeks, preceded or not by enzyme addition, or natural aging for 18 months. The wines were then submitted to a selected and trained panel. Samples were compared using triangular test. Furthermore, a quantitative descriptive analysis was carried out to determine the aroma attributes describing and discriminating the wines from the two varieties.</p><p style="text-align: justify;"><strong>Conclusion</strong>: The glycoconjugates increased the global aromatic complexity, and enhanced the fruity aromas in Grenache wines and the leather or olive aromas in Syrah wines. The use of glycosidase enzymes led to a stewed fruit character in Grenache wines, whereas in Syrah wines, the samples enriched with glycosides differed according to the « terroir ».</p><p style="text-align: justify;"><strong>Significance and impact of study</strong>: This study showed the impact of the glycosidic fraction of the grapes on the varietal aroma of wines. Furthermore, comparisons of the results obtained by both aging techniques highlight the experimental interest of the aging model but also its limits.</p>

Sensory characteristics changes of red Grenache wines submitted to different oxygen exposures pre and post bottling

It is widely accepted that oxygen contributes to wine development by impacting its colour, aromatic bouquet, and mouth-feel properties. The wine industry can now also take advantage of engineered solutions to deliver known amounts of oxygen into bottles through the closures. This study was aimed at monitoring the influence of oxygen pick-up, before (micro-oxygenation, Mox) and after (nano-oxygenation) bottling, on wine sensory evolution. Red Grenache wines were prepared either by flash release (FR) or traditional soaking (Trad) and with or without Mox during elevage (FR + noMox, FR + Mox, Trad + noMox, Trad + Mox). The rate of nano oxygenation was controlled by combining consistent oxygen transfer rate (OTR) closures and different oxygen controlled storage conditions. Wine sensory characteristics were analyzed by sensory profile, at bottling (T0) and after 5 and 10 months of ageing, by a panel of trained judges. Effects of winemaking techniques and OTR were analyzed by multivariate analysis (principal component analysis and agglomerative hierarchical clustering) and analysis of variance. Results showed that, at bottling, Trad wines were perceived more animal and FR wines more bitter and astringent. Mox wines showed more orange shade. At 5 and 10 months, visual and olfactory differences were observed according to the OTR levels: modalities with higher oxygen ingress were darker and fruitier but also perceived significantly less animal than modalities with lower oxygen. Along the 10 months of ageing, the influence of OTR became more important as shown by increased significance levels of the observed differences. As the mouth-feel properties of the wines were mainly dictated by winemaking techniques, OTR had only little impact on “in mouth” attributes.

Effects of timing of leaf removal on yield, berry maturity, wine composition and sensory properties of cv. Grenache grown under non irrigated conditions

<p style="text-align: justify;"><strong>Aims</strong>: The objective of this study was to investigate the effects of timing of leaf removal on yield components, berry sensory characteristics, composition and sensory properties of Vitis vinifera L. Grenache wines under non-irrigated conditions.</p><p style="text-align: justify;"><strong>Methods and results</strong>: The effects of timing of defoliation (fruit set and veraison) on yield components, berry maturity, wine composition and sensory properties of head trained, non irrigated, Grenache vines grown in Rioja appellation were studied. Leaf removal did not significantly modify total leaf area per vine as well as yield components. Grenache berries from early defoliated vines achieved the highest skin and technological maturity. Wine parameters, such as alcohol content, pH, titratable acidity, tartaric acid and total polyphenol index were unaffected by defoliation. Conversely, early leaf removal carried out at fruit set, significantly reduced the malic acid content of the wine and enhanced its colour intensity. Aroma complexity, mouthfeel, tannin quality and persistence were found to be significantly higher in the wine corresponding to the early leaf removal treatment. This was also the most preferred wine in terms of overall value.</p><p style="text-align: justify;"><strong>Conclusion</strong>: This article shows that timing of leaf removal had a marked effect on berry maturity, wine composition and sensory properties of Grenache wines made from grapes grown under dry-farmed conditions.</p><p style="text-align: justify;"><strong>Significance and impact of study</strong>: The results suggest that the timing of defoliation induces significant changes in Grenache wine composition and its sensory attributes. Late leaf removal was much less effective than early leaf removal in affecting final wine composition and quality. Grenache wine from the early defoliation treatment was rated the most preferred as of global value.</p>

Formation of Hydroxyphenyl-pyranoanthocyanins in Grenache Wines: Precursor Levels and Evolution during Aging

Grenache red wines were produced following three different winemaking techniques, that is, small-scale standard experimental wines and industrial-scale wines by both double-mash fermentation and fermentation in Ganimede vats. Wines were analyzed for their color properties, as well as the anthocyanin, flavonol, hydroxycinnamic acid, and pyranoanthocyanin profiles following alcoholic and malolactic fermentation. The evolution of pyranoanthocyanins and their corresponding precursors in the experimental wines was monitored at 6 and 10 months of aging. Wines produced by double-mash fermentation exhibited superior color properties compared to Ganimede wines and the experimental red wines, due to better extraction of flavonols and anthocyanins as well as a lower degree of polymerization. Pyranoanthocyanin formation varied within the different classes of pigments. Vitisins A and B were formed only during alcoholic fermentation. Pinotin A (i.e., the reaction product from malvidin 3-glucoside and caffeic acid) formation took place only during the aging process, whereas formation of hydroxyphenyl-pyranoanthocyanins derived from p-coumaric and ferulic acid followed two different pathways, that is, an enzymatically assisted production during fermentation and a pure chemical formation during aging.

Study of polyamines and their precursor amino acids in Grenache noir and Syrah grapes and wine of the Rhone Valley

Polyamines and their amino acid precursors were determined in Grenache and Syrah grapes and in wines made from these grapes. The compounds analysed were the polyamines putrescine, spermidine, and spermine, in addition to their precursors, ornithine, agmatine and arginine. The analytes were determined by reversed-phase high performance liquid chromatography (HPLC) with fluorescence detection using FMOC (fluorenylmethylchloroformate) as a pre-column derivatising agent Grape clusters were sampled from flowering to full maturity at different developmental stages. In addition, different berry parts were analysed separately from half veraison onwards. It appears that at berryset there is a decrease in the concentration of arginine, whereas polyamine concentrations remain constant at this stage. Concentrations of polyamines increased from must to alcoholic to malolactic fermentation; putrescine was the most abundant in wine (mean concentration after malolactic fermentation, MLF was 4.93 mg/l) followed by spermidine and then spermine (mean concentrations after MLF were 1.84 and 0.17 mg/l, respectively). In three of the four fermentation sites concentrations of all three compounds were greater in Syrah than in Grenache wines. In both varieties, it appears that polyamine biosynthesis occurs preferentially from arginine via agmatine. In all cases, concentrations of polyamines found in these grapes and wines were significantly below the levels typically found in other fermented foods.

Effects of Sewage Sludge Compost on Volatile Organic Compounds of Wine fromVitis viniferacv. Red Grenache

The effect of one application of sewage sludge compost at three rates on the volatile organic compound (VOC) composition of <i>Vitis vinifera</i> cv. Red Grenache wines of two vintages (1999 and 2000) was investigated. After analyzing the 12 major VOC by gas chromatography (GC) and GC/mass spectrometry, results showed significant differences in wine VOC concentrations among the treatments. The first year, application of high rates of sewage sludge compost decreased the total VOC concentrations of wines, especially concentrations of ethyl acetate, ethyl hexanoate, 3-methylbutyl acetate, and ethyl 3-methylbutanoate, which contribute to wine quality. The second year, organoleptic qualities were only slightly distinguished in wines from the different treatments.

Determination of volatile compounds in Grenache wines in relation with different terroirs in the Rhone Valley.

This paper describes the study of 19 wines of the Grenache Noir cultivar obtained from representative soils of the Rhone Valley according to their geographical site, climatic conditions, hydrological regulation, and soil profile. Among the volatile compounds analyzed by GC/MS/FID, the concentrations of the varietal compounds (i.e., beta-damascenone, beta-ionone, and geraniol) and those of the compounds without direct influence on the wine aroma (i.e., hexenols and methanol) indicated the existence of two groups of wines. These concentrations were correlated with grape maturity due to the ecosystem and particularly the soil.

Quantitative determination of free and hydrolytically liberated β-damascenone in red grapes and wines using a stable isotope dilution assay

Quantitative analysis of free and hydrolytically liberated β-damascenone in grapes and wines was developed, using a stable isotope dilution assay. Free β-damascenone was isolated from grapes and wines by diethyl ether–hexane (1:1, v/v) extraction and the precursor(s) (glycosidic, polyols) of β-damascenone using Sep-Pak Plus C 18 RP cartridges. Hydrolytically liberated β-damascenone was generated by acid hydrolysis from the precursor(s) extract. Red wines from Bordeaux (Merlot, Cabernet Sauvignon and Cabernet Franc, 1995 and 1996 vintage), Burgundy (Pinot Noir, 1995 and 1996 vintage) regions and Grenache wines from Chateauneuf du Pape and Côtes du Rhône (1995 vintage) were analysed to quantify free β-damascenone. The wines made from Grenache and Cabernet Sauvignon (1996 vintage) grapes presented the highest mean amounts of free β-damascenone, 5.4 and 5.5 μg l −1, respectively. Merlot, Cabernet Sauvignon and Cabernet Franc grapes of Bordeaux (1996 vintage) and their corresponding wines were analysed for quantification of free and hydrolytically liberated β-damascenone. The levels of hydrolytically liberated β-damascenone in grapes could predict closely the levels of free β-damascenone in the corresponding wines after one year of ageing, i.e., almost half the levels found for the grape samples. The influence of enzyme and heat treatment of Merlot wine samples on their β-damascenone levels was studied. Heat treatment doubled the levels of this compound, but enzyme treatment generated, in the corresponding wines, half the levels of β-damascenone found in the non-enzyme treated wines.