Aroma characterization of red wines from cv. Bobal grape variety grown in La Mancha region

Bobal is an indigenous Spanish cultivar, principally grown in the region of Valencia. The volatile composition of young red wines made from the cv. Bobal grape variety grown in the La Mancha region of Spain has been studied over five vintages by instrumental analysis to determine the influence of grape variety on the aroma of wine. Free and glycosidically-bound aroma compounds were isolated by solid phase extraction (SPE) using dichloromethane and ethyl acetate respectively to later be analyzed using gas chromatography-mass spectrometry (GC/MS). One hundred and twelve (112) free aroma compounds and ninety-six (96) bound aroma compounds were identified and quantified in Bobal wines oven this five year period. Based on the result, Bobal wine presents a complex chemical profile with a wealth of aromas in its aromatic composition.     

Binding of oak volatile compounds by wine lees during simulation of wine ageing

The retention of wine volatile compounds by wine lees could have an influence on the quality of the product. The aim of this work was to study the binding of wine volatile compounds from oak wood by the wine lees during simulation of wine ageing. The compounds with the most affinity for the lees were eugenol, 4-propylguaiacol, 4-methylguaiacol, furfural and 5-methylfurfural. Lees also bound other compounds important for aroma in aged wine such as oak lactones, although to a lesser degree. Guaiacol and γ-nonalactone were the only compounds studied that were not bound by the lees. Because the lees bind important compounds to wine aroma, ageing red wine in oak barrel in presence of lees could diminish the impact of the aromatic compounds from oak wood on wine aroma.     

Different commercial yeast strains affecting the volatile and sensory profile of cava base wine

36 semi-industrial fermentations were carried out with 6 different yeast strains in order to assess differences in the wines' chemical and volatile profile. Two of the tested strains (Y3 and Y6) showed the fastest fermentation rates throughout 3 harvests and on 2 grape varieties. The wines fermented by three of the tested strains (Y5, Y3 and Y4) stand out for their high amounts of esters and possessed the highest fruity character. Wines from strains producing low amounts of esters and high concentrations of medium chain fatty acids, higher alcohols and six-carbon alcohols were the least appreciated at the sensory analysis. The data obtained in the present study show how the yeast strain quantitatively affects the final chemical and volatile composition of cava base wines and have repercussions on their sensory profile, independently of must variety and harvest year.     

Analysis of volatile compounds of mango wine

The volatile compounds of mango wine were isolated by continuous solvent extraction and analysed by GC-FID and GC-MS. A total of 102 volatile constituents were identified and quantified. The mango wine accounted for about 9 mg/l of volatile compounds, which included 40 esters, 15 alcohols, 12 terpenes, 8 acids, 6 aldehydes and ketones, 4 lactones, 2 phenols, 2 furans, and 13 miscellaneous compounds. Isopentanol and 2-phenylethanol were the major constituents. A tentative study to estimate the contribution of the identified compounds to the aroma of the wine, on the basis of their odour activity values, indicated that the compounds potentially most important to mango wine included ethyl butanoate and decanal.     

Development of volatile compounds of cava (Spanish sparkling wine) during long ageing time in contact with lees

In order to study the evolution of volatile compounds during long ageing times in contact with lees (more than 2 years), Headspace–solid phase microextraction (HS/SPME) method was applied to different cavas (Spanish Sparkling wine). Two different fiber coatings were used: PDMS which extracts the analytes by partitioning and DVB–CAR–PDMS which extracts either by partitioning or physically trapped the target compounds. Even though the volatile profile obtained by gas chromatography/mass spectrometry (GC/MS) was similar, the triple phase seems to be more suitable to follow the development of the volatile profile during its ageing time. Hexyl, 2-phenylethyl and isoamyl acetates significantly decrease over time, while 1,2-dihydro-1,1,6-trimethylnaphthalene (TDN), vitispirane and diethyl succinate significantly increase during ageing in contact with lees.     

Chemical compounds and mechanisms involved in the formation and stabilization of foam in sparkling wines

The visual properties of sparkling wine including foam and bubbles are an indicator of sparkling wine quality. Foam properties, particularly foam height (FH) and foam stability (TS), are significantly influenced by the chemical composition of the wine. This review investigates our current knowledge of specific chemical compounds and, the mechanisms by which they influence the foam properties of sparkling wines. Grape and yeast proteins, amino acids, polysaccharides, phenolic compounds, organic acids, fatty acids, ethanol and sugar are examined with respect to their contribution to foam characteristics in sparkling wines made with the Traditional, Transfer, and Charmat and carbonation methods. Contradictory results have been identified that appear to be due to the analytical methods used to measure and quantify compounds and foam. Biopolymer complexes are discussed and absent knowledge with regards to thaumatin-like proteins (TLPs), polysaccharides, amino acids, oak-derived phenolic compounds and organic acids are identified. Future research is also likely to concentrate on visual analysis of sparkling wines by in-depth imaging analysis and specific sensory analysis techniques.     

Concentration of volatile compounds in Chardonnay wine fermented in stainless steel tanks and oak barrels

The influence of the type of container used in alcoholic fermentation on the formation of volatile compounds in wine from Chardonnay variety was studied. To do so, must from Chardonnay variety was fermented in both stainless steel tanks and in new Nevers oak barrels. The results obtained showed that wine fermented in barrels had a greater concentration of higher alcohols and esters than wine fermented in tanks. Concentration of isoamyl acetate, ethyl hexanoate, ethyl octanoate and ethyl decanoate was four times higher in wine fermented in oak barrels than in wine fermented in stainless steel tanks. With regard to the concentration of acids, a greater concentration of medium-chain fatty acids (C6:0–C10:0) was noticeable in wine fermented in oak barrels. Given that these acids are toxic for the yeasts, they may be responsible for the slower fermentation rate of wine fermented in oak barrels.     

Volatile composition of Bobal red wines subjected to alcoholic/malolactic fermentation with oak chips

The effect of wood, in the form of oak chips, on the volatile composition of Bobal red wines caused by adding oak chips at different stages of the fermentation process has been studied. Aroma compounds were isolated by solid phase extraction (SPE) for subsequent analysis by gas chromatography–mass spectrometry (GC/MS). Bobal control wine was produced according to traditional winemaking processes, without oak chips. Oak chips were added to the rest of the wines at two dose levels (3 and 6 g/L) at different stages of the winemaking process: at one week during alcoholic fermentation (AF), during malolactic fermentation (MLF) and in young, red Bobal wine. Wines fermented with oak chips during AF showed higher concentrations of the ethyl esters of straight-chain fatty acids and ethyl, hexyl and isoamyl acetates than the control wine. A similar, trend was observed for higher alcohols. Higher concentrations of benzene compounds, oak lactones and furanic compounds were found in wines in contact with oak chips during MLF followed by young Bobal oak wines. These results reveal that the point of addition during the winemaking process and the dose level of oak chips used have a significant effect on the volatile composition of Bobal red wines.     

Changes of volatile compounds in wine vinegars during their elaboration in barrels made from different woods

Changes in the volatile components of red wine vinegars and balsamic vinegars were investigated during 1 year of aging in wood barrels and bottles. Barrels of four different woods (oak, chestnut, acacia and cherry) were used. A total of 57 volatile compounds were analysed by Gas Chromatography–Flame Ionization Detection (GC–FID) and Headspace Sorptive Extraction GC–Mass Spectrometry (HSSE-TD–GC–MS). We observed significant increases in the total content of volatile compounds only for balsamic vinegars. The concentrations of ethyl furoate, ethyl benzoate, benzaldehyde and acetophenone were highest in cherry barrels. These compounds, then, seem to be characteristic of this wood. Oak lactones presented the highest increases for vinegars aged in oak. Eugenol was only present in vinegars aged in chestnut and oak barrels. Oak and cherry seem to be the best type of wood for aging of vinegar due to their distinctive aromatic characteristics.     

Influence of the use of bentonite as a riddling agent on foam quality and protein fraction of sparkling wines (Cava)

This paper studies how the use of bentonite to facilitate the riddling process affects the foam properties and the protein fraction of sparkling wines (Cava). In all monovarietal sparkling wines (Macabeu, Xarel.lo, Parellada, Chardonnay and Pinot Noir), the addition of bentonite produced a statistically significant diminution of the Mosalux parameters (HM and HS). This depreciation of the foam quality may be attributed to the direct interaction of bentonite with wine proteins. Concretely the use of bentonite caused a diminution of more of 80% of total the soluble protein. Gel filtration by FPLC showed that bentonite particularly affected the 60 kDa and 20–30 kDa protein fraction. The high molecular fraction, on the other hand, was not affected.     

Analysis of volatile compounds of pineapple wine using solid-phase microextraction techniques

An analytical procedure based on headspace solid-phase microextraction (HS-SPME) method combined with GC–MS was developed for the extraction and quantification of volatile compounds from pineapple wine. Different sample preparation (SPME fibre type, addition of sodium chloride, extraction time and temperature) were evaluated to optimise the method. For the final method, 8 ml of pineapple wine were placed in a 15 ml headspace vial with addition of 1 g of NaCl; a polydimethylsiloxane SPME fibre was used for extraction at 30 °C for 30 min with continuous stirring. The volatile compounds have shown a good linearity in the range of concentrations studied with regression coefficients higher than 0.98, and the reproducibility expressed as relative standard deviation ranged from 4.2% (2-phenylethyl acetate) to 7.1% (ethyl benzoate). The values obtained for detection and quantification limits were low enough to permit the determination of volatiles in pineapple wine. Using this method, 18 volatiles were identified, including 13 esters, 4 alcohols and one acid. Ethyl octanoate, ethyl acetate, 3-methyl-1-butanol and ethyl decanoate were the major constituents. A tentative study to estimate the contribution of the identified compounds to the aroma of the wine, on the basis of their odour activity values (OAV), indicated that the compounds potentially most important to pineapple wine included ethyl octanoate, ethyl acetate and ethyl 2-methylpropanoate.     

Evolution of aroma compounds in sparkling ciders

This paper reports the influence of yeast strain and aging time on the volatile composition of sparkling cider made according to the traditional method. Two sparkling ciders were obtained from the same base cider using a selected cider yeast strain (Saccharomyces bayanus) and a commercial wine yeast strain (Saccharomyces cerevisiae). Analysis of volatile compounds (alcohols, esters and carbonylic compounds) were performed every 3 months, from 3 to 15 months. The analysis of variance revealed that the majority of differences between sparkling ciders are due to the aging time. Acetaldehyde and acetoin decrease with time, while higher alcohols, ethyl acetate, ethyl lactate and ethyl octanoate significantly increase during aging in contact with lees. The concentrations of methanol, 2-phenyletanhol, ethyl lactate and ethyl octanoate were higher in the cider made with the selected yeast strain (S. bayanus).     

The production and consumer perception of sparkling wines of different carbonation levels

The objective of this study was to determine the influence of carbonation level on the sensory and chemical properties of traditional sparkling wine and identify the level of carbonation that could be perceived by consumers. Sparkling wine treatments (n?=?11) were produced through the addition of different concentrations of dextrose at bottling to create sparkling wines varying in carbonation (CO₂) level. Final wines ranged in CO₂ concentration from 0 to 7.5?g?CO₂/L (p?≤?.05). A consumer sensory evaluation panel (n?=?48) evaluated the wines using a paired comparison test in which a sparkling wine at CO₂ concentrations of 1.2, 2.0, 4.0, 5.8, or 7.5?g CO₂/L was compared to the control sparkling wine (0?g CO₂/L) for mouthfeel attributes (carbonation and bite) and sour taste. Results showed significant differences (p?≤?.001) between the control and sparkling wines containing 2.0, 4.0, 5.8, and 7.5?CO₂/L for the mouthfeel attributes of carbonation and bite, suggesting that a minimum CO₂ concentration of >1.2?g?CO₂/L was required for consumers to detect mouthfeel differences compared to the control. The results of this study provide sparkling winemakers and manufacturers of other carbonated products with information regarding the level of CO₂ perceived by consumers of sparkling wines.     

Biotechnologies in sparkling wine production. Interesting approaches for quality improvement: A review

Sparkling wines are produced by a secondary fermentation of a base wine followed by a prolonged ageing in contact with lees. In the traditional method, the refermentation takes place in the same bottle used for market distribution. The autolysis of yeasts occurs during the ageing of sparkling wines, thus causing the release of many parietal and cytoplasmic compounds which have a great influence on sparkling wine’s quality. The modern technologies for the production of sparkling wine are very different from the one developed by Abbot Dom Pierre Pérignon in the 17th century. Over the years, many advances have been made, this paper aims at reviewing the recent knowledge in the application of biotechnologies for the improvement of sparkling wine’s quality, in particular the factors affecting foaming properties and sensory qualities. Future perspectives and trends are also considered.     

基于HS-GC-IMS分析樱桃酒中的挥发性风味物质

以日照产樱桃为原料酿造苹果酒，利用顶空气相色谱-离子迁移谱（HS-GC-IMS）分析樱桃酒中挥发性风味成分，并对樱桃酒中挥发性物质进行指纹图谱、离子图谱和香气特征分析。结果表明，樱桃酒中共检出23种挥发性成分，其中酯类9种，醇类5种，醛类4种，酮类3种，吡嗪类1种和有机酸1种，大部分挥发性物质由酿酒酵母（Saccharomyces cerevisiae）在樱桃酒发酵过程中产生，这些物质构成了樱桃酒的主要风味，樱桃酒的香气类型主要为水果香、柔和果香和青香。     

Phenolic compounds present in natural haze protein of Sauvignon white wine

Protein haze in white wines remains a problem for wineries. In addition to protein composition, many other factors have been identified that can participate in and even trigger the appearance of hazes. Phenolic compounds may be one of the non-protein factors involved in protein haze formation. The aim of this study was to identify and quantify the polyphenols present in the natural precipitate of a Sauvignon wine. The identification and quantification of polyphenols present in wine before and after natural precipitation and also in a natural precipitate were carried out by GC/MS and HPLC/ESI-TOF. The natural precipitate was also hydrolyzed in an acidic medium (Bate-Smith reaction). The results indicate that several phenolic compounds were present in the protein haze (tyrosol, trans-p-coumaric, trans-caffeic, vanillic, protocatechuic, syringic, gallic, ferulic, shikimic acids, (+)-catechin, ethyl coumaric acid ester and quercetin). Moreover, the detection of cyanidin after acid hydrolysis indicates the presence of procyanidins.     

Hydrolysis and formation of volatile esters in New Zealand Sauvignon blanc wine

The evolution of the varietal thiol 3-mercaptohexanol acetate (3MHA) and other key aroma compounds has been monitored in New Zealand Sauvignon blanc wines stored for 1 year at three different temperatures (5, 10 and 18 °C). The main processes that occurred in the Sauvignon blanc wines during bottle ageing were hydrolysis of 3MHA and other acetate esters, hydrolysis of ethyl esters of fatty acids, and the formation of ethyl esters of branched acids. The kinetic parameters of ester hydrolysis, including reaction rate constants and activation energies, were determined, which allow prediction of future wine composition based upon storage temperature and time. It was found that 3MHA had the highest reaction rate constant, meaning that this compound is the most unstable, particularly at higher storage temperatures, and that it disappeared very fast during wine storage.