Aroma series as fingerprints for biological ageing in fino sherry‐type wines

BACKGROUND: The contribution of flor yeasts and wood to the ageing of fino sherry type wines was studied by using capillary column gas chromatography to analyse 72 aroma compounds in wines subjected to biological ageing. The odour activity values (OAVs) for the different compounds were classified into eight odorant series that describe the aroma profile of these wines (fruity, chemical, balsamic, vegetable, fatty, empyreumatic, floral and spicy). RESULTS: The fruity samples made up the major series followed by the fatty and spicy at the end of the ageing period. The application of a linear regression model to the OAVs for the different series revealed that the fruity series, which is related to the flor yeasts activity, and the spicy series, which includes the compounds released by wood, are those most closely representing the changes in the aroma of these wines during their ageing. CONCLUSIONS: The comparison of the OAVs for fruity and spicy series along the ageing period can be used to establish a balance between the aroma compounds contributed by the flor yeasts and those extracted from the wood. This balance should be particularly considered in works aimed at shortening the ageing time for these wines. Copyright © 2007 Society of Chemical Industry     

Impact of phytosanitary treatments with fungicides (cyazofamid, famoxadone, mandipropamid and valifenalate) on aroma compounds of Godello white wines

Cyazofamid, famoxadone, mandipropamid and valifenalate, four new fungicides for controlling downy mildew in vine, were applied to an experimental vineyard producing Vitis vinifera white grapes of the Godello variety. Following harvest, the grapes were subjected to single vinification runs. The odour activity values (OAVs) for the Godello white wines obtained were estimated with a view to assessing potential alterations of their aroma composition by effect of the phytosanitary treatments. Several fatty acids, their esters and acetates were formed during the winemaking process in high levels and could be expected to strongly influence the aroma of the wines by introducing floral, fruity and spicy nuances. The concentrations of six compounds (2-phenylethyl acetate, ethyl butanoate, ethyl octanoate, 4-vinylguaiacol, 3-methylbutanoic acid and methionol) were found to suffice with a view to discriminating between wines from grapes treated with fungicides under Critical Agricultural Practices (CAP) and under Good Agricultural Practices (GAP).     

Headspace solid‐phase micro extraction coupled to comprehensive two‐dimensional with time‐of‐flight mass spectrometry applied to the evaluation of Nebbiolo‐based wine volatile aroma during ageing

This study presents the application of a headspace solid‐phase microextraction (HS‐SPME) method on the analysis of Nebbiolo‐based wine volatiles by comprehensive two‐dimensional gas chromatography (GC×GC) and time‐of‐flight mass spectrometry (TOF‐MS). The aroma patterns were established for different samples of Nebbiolo‐based wines, aged in oak wood barrels for 18 months at constant temperature. The methodology allowed for the simultaneous analysis of over 130 different volatile compounds detected in the headspace. The odour activity values (OAVs) were assessed to identify potentially important odorants of Nebbiolo‐based wine during ageing. The highest OAVs were obtained for several compounds such as ethyl octanoate, ethyl hexanoate, isoamyl acetate, β‐damascenone, ethyl cinnamate, ethyl 3‐methylbutanate and acetaldehyde. Ethyl butanoate, octanoic acid, ethyl dihydrocinnamate and γ‐nonalactone were also at concentrations higher than their corresponding threshold. Also vanillin, (E)‐whisky lactone, (Z)‐whisky lactone, guaiacol and 4‐ethyl guaiacol seem to be important odorants after oak wood ageing period.     

Key aroma volatile compounds of gulupa (Passiflora edulis Sims fo edulis) fruit

By application of the aroma extract dilution analysis of gulupa (Passiflora edulis Sims fo edulis), fruit pulp extract obtained by solvent-assisted flavour extraction, and also comparison of chromatographic, spectroscopic (mass spectrum), and odour properties with standards, β-ionone, γ-nonalactone, ethyl butanoate, and ethyl cinnamate were identified as volatiles exhibiting the highest flavour dilution (FD) factor. Among the nineteen odour-active compounds of gulupa, only those showing the highest FD factors were quantified by stable isotope dilution assay. After calculation of odour activity values (OAVs; ratio of concentration to odour threshold in water), ethyl butanoate, ethyl hexanoate, and β-ionone were identified as key aroma compounds in gulupa, responsible for the fruity and floral odour notes.     

Application of new fungicides under good agricultural practices and their effects on the volatile profile of white wines

Three new commercial fungicides to control downy mildew (Plasmopara viticola), which contain new generation fungicides (benalaxyl, iprovalicarb and piraclostrobin) were applied under Good Agricultural Practices (GAP) in an experimental vineyard producing white grapes (Vitis vinifera) Godello var. Once white grapes were harvested, single vinifications were performed. To evaluate possible modifications in aroma composition of wines, Odour Activity Values (OAVs) were estimated due to this parameter provides information about sensorial changes. Fungicide residual levels found in treated wines with respect to the control wine reduced the varietal aroma of wines attributed to geraniol. However, treated wines showed an increase in the fruity aroma due to several ethyl esters (ethyl hexanoate, ethyl octanoate, and ethyl decanoate) and acetates (3-methyl-1-butyl acetate and 2-phenylethyl acetate) increased their levels and OAVs in presence of fungicide residues; these secondary products of the fermentation process influence strongly the aromatic profile of young wines.     

Effect of storage temperature on the chemical composition and sensory profile of Sauvignon Blanc wines

Background and Aims: Most white wines lose fresh and fruity characteristics, associated with volatile esters, during ageing in the bottle. A higher storage temperature accelerates these changes. The aim of this study was to examine the influence of storage temperature on the chemical and sensory properties of Sauvignon Blanc wines. Methods and Results: Three commercially bottled Sauvignon Blanc wines from the 2008 and 2009 vintages were stored at 5, 10, 18°C and at room temperature for 12 months. Wines stored at warmer temperatures (18°C and room temperature) contained lower concentrations of acetate esters, including the prominent varietal thiol 3MHA, and ethyl esters of fatty acids, than the wines stored at cooler temperatures (5 and 10°C). A warmer temperature accelerated the rate of ester hydrolysis. Conversely, the concentrations of ethyl esters of branched acids were higher in wines stored at the warmer temperatures. The sensory profile of the wines was assessed after 12 months for the two 2008 wines and after 8 months for the 2009 wine. The wines stored at cooler temperatures were characterised by higher fruity and fresh vegetal aromas, whereas the wines stored at warmer temperatures exhibited the opposite sensory profile, with dominant woody/smoky/oaky, buttery, flinty and canned asparagus notes. Conclusions: These results indicate that temperature‐dependent hydrolysis processes are critical for Sauvignon Blanc aroma stability during the first year in the bottle. Significance of the Study: Cool storage temperature conditions can significantly increase the shelf‐life of Sauvignon Blanc wines by preserving their fruity and fresh green characters.     

Fortification Spirit, a Contributor to the Aroma Complexity of Port

Five 1999 varietal Douro table wines (Touriga Nacional, Touriga Francesa, Tinta Roriz, Tinto Cão, Tinta Amarela/Tinta Barroca mixed), one aguardente and five model Ports (aguardente fortified table wines) were quantified for 15 compounds by GC‐MS using selected characteristic ions. Although aguardente constitutes around one fifth of the volume of Port, it was found to be the major contributor of numerous compounds including: ethyl hexanoate (81 to 90%); ethyl octanoate (94 to 98%); ethyl decanoate (98 to 99%); benzaldehyde (87 to 94%); a‐terpineol (76 to 91%); linalool (58 to 91%); ethyl hydrocinnamate (100%). Aguardente volatiles make an essential contribution to young Port aroma, adding fruity, balsamic and spicy aroma complexity.     

Effect of cofermentation of grape varieties on aroma profiles of la mancha red wines

The effect of winemaking using blends of red grape varieties cultivated in La Mancha region (Spain) on the aroma profile of wines was researched by chemical characterization. Free and glycosidically bound aroma compounds were isolated by solid phase extraction using dichloromethane and ethyl acetate, respectively, as solvents in elution and then analyzed by gas chromatography-mass spectrometry. Free and bound volatile compounds were analyzed in Cencibel, Bobal, and Moravia Agria monovarietal wines, and in 3 wines obtained with the blending of grapes: Cencibel (50%) + Bobal (50%); Cencibel (50%) + Moravía Agria (50%); Cencibel (33%) + Bobal (33%) + Moravía Agria (33%). Aroma compounds were studied in terms of odor activity values (OAVs). Ninety free aroma compounds and sixty-five bound aroma compounds were identified and quantified. The odor activity values for the different compounds were classified into 7 odorant series. The fruity and sweet series contributed most strongly to the aroma profile of all wines, independently of the winemaking technique used. In general, co-winemaking wines present a more complex chemical profile than monovarietal wines. Practical Application: Some grape varieties could benefit from this process with the presence of other varieties that might have an excess of aroma compounds. In this study, the wines were elaborated by blending different grape varieties together; this process implies co-maceration and co-fermentation steps. The co-winemaking technique could benefit from additional molecules provided by the other varieties, which results in a more complex formation than in the case of monovarietal wines. This technique provides a viable alternative to traditional winemaking methods for improving and enhancing the sensory profile of elaborated wines.     

Effect of saliva esterase activity on ester solutions and possible consequences for the in‐mouth ester release during wine intake

The aim of this study was to investigate the role of saliva esterase activity on carboxylic esters typically associated with pleasant and fruity aromas in wine. For this, ex vivo experiments using the same fresh and inactivated (without enzymatic activity) human saliva with a mixture of carboxylic esters with different aliphatic chain length (ethyl butanoate, ethyl pentanoate, ethyl hexanoate, ethyl octanoate, ethyl decanoate, and isoamyl acetate) were prepared. Liquid–liquid extraction with dichloromethane and GC–MS analysis were applied to the saliva systems in order to determine the reduction in ester content and the formation of their corresponding metabolic products (carboxylic acids) in the saliva systems before and after incubation at 37C. In addition, to check if there was a relationship between the susceptibility of esters to saliva hydrolysis and the amount of in‐mouth ester release during wine intake, the remaining oral amount of each ester was determined by comparing the intraoral amount immediately after spitting out the wine and 4 min later. Ex vivo experiments showed ester degradation by saliva esterase enzymes mainly acted on long chain esters (ethyl octanoate and ethyl decanoate), which gave rise to the formation of their corresponding carboxylic acids. Nonetheless, in spite of their higher susceptibility to saliva enzymes, in vivo experiments showed that long chain carboxylic esters remained in the oral cavity long after swallowing. This confirmed that ester hydrophobicity is closely related to the in‐mouth temporal release of these odorants and, therefore, behind wine aroma persistence. In wines, esters represent a group of aromatic compounds of great interest since they are linked to pleasant fruity aroma nuances. Today wine consumers are demanding fresh and long persistent fruity aromatic wines. The present research contributes to better understanding the relationship between ester content in the wine and oral aroma release experienced during wine tasting, considering the changes in these compounds during oral processing. This is a necessary step when trying to unravel the factors involved in wine aroma perception and in consumer preferences, and it represents a necessary knowledge in promoting winemaking practices (e.g., the use of selected microorganisms) for improving the type and amount of these aroma compounds in the wine.     

First study of determination of aromatic compounds of red wine from Vitis vinifera cv. Castañal grown in Galicia (NW Spain)

Wines produced from Vitis vinifera cv. Castañal from Galicia (NW Spain), harvest 2002 and 2003, were submitted to gas chromatography (GC/FID). A total of 36 varietal and fermentative aroma compounds were identified and quantified. The total concentration of aroma compounds in 2002 and 2003 vintage was 872.06 and 520.70 mg/L, respectively, which include free and bound terpenes and C₁₃-norisoprenoids, alcohols, acetates and ethyl esters. To estimate the contribution of specific compound to the aroma, the odour activity value (OAV) was calculated using the concentration of each component and the corresponding odour threshold reported in the literature. From 36 compounds identified, 10 were determined as the most powerful odorants: β-ionone, 3-methyl-1-butanol, benzyl alcohol, 2-phenylethanol, ethyl acetate, isoamyl acetate, ethyl lactate, ethyl butyrate, ethyl hexanoate and ethyl octanoate. These data suggested Castañal wines as a fruity (blackberry) and floral (rose) product.     

Volatile components of Zalema white wines

The volatile composition of young white wines from Vitis vinifera cv. Zalema, an autochthonous grape variety in Huelva (southern Spain), has been studied by gas chromatography-olfactometry (GC-O) and techniques of quantitative analysis. This is the first time that an olfactometric analysis has been reported in wines made from this grape variety. The quantitative chemical study has shown 71 volatile compounds, of which 23 were in concentrations above their thresholds. On the basis of the odour activity values (OAVs), the most potent odorants were fermentative compounds, mainly fatty acids and their ethyl esters. Two norisoprenoids, β-damascenone and β-ionone, two alcohols (isoamyl alcohol and β-phenylethanol), three volatile thiols, 4-mercapto-4-methyl-2-pentanone, 3-mercaptohexyl acetate and 3-mercapto-1-hexanol, and two carbonyl compounds (acetaldehyde and phenylacetaldehyde) also exhibited OAVs > 1. The GC-O study corroborated these results, showing that five esters (isoamyl acetate, ethyl hexanoate, ethyl butyrate, ethyl isovalerate and ethyl octanoate), isoamyl alcohol and β-damascenone can be considered as the most powerful odorants of Zalema wines.     

Volatile constituents of roasted tigernut oil (Cyperus esculentus L.)

BACKGROUND: Volatile compounds play a key role in determining the sensory appreciation of vegetable oils. In this study a systematic evaluation of odorants responsible for the characteristic flavour of roasted tigernut oil was carried out. RESULTS: A total of 75 odour‐active volatiles were identified. From these, 13 aroma compounds showing high flavour dilution factors in the range of 16 to 128 were quantified by their odour activity values (OAVs). On the basis of high OAVs in oil, the following aroma compounds [vanillin (chocolate, sweet vanilla), 5‐ethylfurfural (caramel, spicy), 2,3‐dihydro‐3,5‐dihydroxy‐6‐methyl‐4H‐pyran‐4‐one (caramel), phenyl acetaldehyde (honey‐like), ethanone, 1‐(4‐hydroxy‐3‐methoxyphenyl) (faint vanilla)] were elucidated as important contributors to the overall chocolate, sweet vanilla, butterscotch aroma of the oil. CONCLUSION: Odorants with high concentrations in the roasted tigernut oil such as 5‐hydroxymethylfurfural, ethyl hexadecanoate, n‐propyl‐9,12‐octadecadienoate gave relatively low OAVs, so their contributions to the overall orthonasal aroma impression of roasted tigernut oil can be assumed to be low. © 2012 Society of Chemical Industry     

基于GC-O、OAV及Feller加和模型对酱香型习酒特征香气成分的分析

通过气相色谱-质谱联用仪、气相色谱硫磷检测器研究3种酱香型习酒(习酒蓝、习酒印象贵州、习酒银质)中的挥发性香气成分,分别鉴定出99、96、98种香气成分,其中各包含12种含硫化合物.基于气相色谱嗅闻仪和香气活性值(odor activity value,OAV)方法,表明己酸乙酯(OAV:1720～1992)、丁酸乙酯...     

香气活度值法结合PLSR用于梨酒特征香气物质筛选与鉴定

采用固相微萃取-气相色谱-质谱对市售3种梨酒香气物质进行分离鉴定,共检出43种挥发性成分,其中醇类16种、酯类15种、醛类4种、酮类2种、酚类1种、酸类3种和其他化合物2种。结合香气活度值(odor activity value,OAV)和偏最小二乘回归(partial least squares regression,PLSR)确定梨酒特征香气物质并推断其对梨酒香气的贡献程度。OAV结果表明:梨酒特征香气物质主要为异丁醇、1-辛醇、1-壬醇、苯乙醇、丁酸乙酯、3-甲基丁酸乙酯、乙酸异戊酯、己酸乙酯、辛酸乙酯、β-大马士酮、丁香酚。建立6个感官属性(发酵香、酸香、果香、花香、甜香、清香)与43种香气物质的PLSR模型表明,苯甲醇、正丁醇、丁二酸二乙酯的OAV小于1,但对梨酒的香气有贡献,经OAV确定的梨酒特征香气物质与发酵香和甜香属性具有很好的相关性,而在清香、酸香、果香和花香上的相关性不明显。