不同产地和烘烤程度橡木片对葡萄酒陈酿香气的影响

采用顶空固相微萃取和气相色谱-质谱联用技术,测定不同产地和烘烤程度橡木片陈酿的葡萄酒中主要陈酿香气成分,并进行主成分分析和判别分析。结果表明,橡木产地和烘烤程度2 种因素对葡萄酒中的陈酿香气成分大多具有显著或极显著影响,糠醛、5-甲基糠醛、顺式橡木内酯、香草醛、愈创木酚、4-甲基愈创木酚、丁子香酚、4-乙基苯酚和4-乙基愈创木酚,9 种化合物均是受烘烤程度的影响更大,而反式橡木内酯、反式异丁子香酚,2 种化合物则受产地因素的影响更大。主成分分析结果表明,提取的3 个主成分的方差累计贡献率达到83.8%,能够反映不同橡木对葡萄酒陈酿香气的影响。通过判别分析,确定不同橡木陈酿的葡萄酒,香气成分产生差异的主要化合物,并建立了区分橡木产地和烘烤程度的分类模型,可根据各种陈酿香气成分的含量,判别不同产地和烘烤程度橡木陈酿的葡萄酒。     

The effect of successive uses of oak barrels on the extraction of oak-related volatile compounds from wine

Changes in the concentration of furfuryl compounds, guaiacol and 4‐methylguaiacol, cis‐ and trans‐oak lactone, and vanillin were studied during the maturation of wines in oak barrels of different origins (French oak and American oak). The rate at which these volatile compounds accumulated in the wines followed a curve that fits to mathematical models. The changes in concentration were usually consistent with diffusion kinetics. When the barrels are new, the concentration gradient between the wood surface and the wine is high, so diffusion occurs quickly, especially in the case of lactones, the extraction rate of which could be fitted to a power curve. After some time of maturation, the concentration gradient is not so large and furthermore, the wood surface may be exhausted of some compounds so the rate of extraction decreases. During the second fill, the rate of accumulation of these compounds in the wine was almost linear, especially during the first 6 months of storage, and the quantities measured in wine were much lower. The concentration of some compounds, increased during the final 3 months (between days 180 and 270), exhibiting a quadratic curve when plotted. Furfuryl aldehydes behaved differently as they are extracted very rapidly from the first millimetres of wood surface and transformed into furfuryl alcohol, a compound with no organoleptic significance.     

Use of microfungi in the treatment of oak chips: possible effects on wine

BACKGROUND: Oak barrels are commonly used in the aging of wines and spirits because of their positive effects on the product. In recent years the addition of oak chips has been used to introduce desirable wood aromas and flavours into wines. In this study, oak chips in saline solution or laboratory medium were inoculated with Penicillium purpurogenum, Aureobasidium pullulans, Phialemonium obovatum, Phanerochaete chrysosporium and a combination of Ph. chrysosporium and A. pullulans. After 12 weeks of incubation, oak chips (2 g L^?1) were macerated in a red wine for 17 days. Gas chromatography/mass spectrometry and high‐performance liquid chromatography were used to evaluate 14 compounds, namely furfural, furfuryl alcohol, guaiacol, syringol, cis‐β‐methyl‐γ‐octalactone, 2‐phenylethanol, 4‐vinylguaiacol, benzyl alcohol, 2,3‐butanediol, γ‐butyrolactone, benzaldehyde, 4‐ethylguaiacol, gallic acid and ellagic acid. RESULTS: The microfungal treatments increased the concentration of some components. In particular, P. purpurogenum resulted in a significant improvement in the levels of guaiacol, furfural, syringol, furfuryl alcohol and 2‐phenylethanol. CONCLUSION: Penicillium purpurogenum and Ph. chrysosporium showed a constant trend (enrichment of furfural and benzaldehyde) independent to some extent of the medium used for chip treatment. Copyright © 2010 Society of Chemical Industry     

Consideration of the influence of aging process,type of wine and oenological classic parameters on the levels of wood volatile compounds present in red wines

The contents of the volatile compounds extracted from wood: cis- and trans-whiskylactones, vanillin, syringaldehyde, furfural, 5-methylfurfural, eugenol, guaiacol, p-ethyl-phenol and p-ethylguaicol have been studied in 12 single-variety wines aged in new American oak barrels. The concentration of these compounds were determined after the following combinations of time in wood and time in bottle: 0 months in wood plus 18 months in bottle, 4 months in wood  + 14 months in bottle, 9 months in wood + 9 moths in bottle and 12 months in wood + 6 months in bottle. According to the composition of the wines, it is possible to conclude in general, that, the extraction of these compounds was faster during the first four or 9 months of aging in wood, depending on the wines. After 12 months of oak maturation, the extraction of these compounds slowed down. Furthermore, the final concentrations of these volatile compounds were different among studied wines. These differences could be related to some of the values of some of their oenological parameters, such as the contents of tartaric acid and sulphur dioxide of each wine.     

不同类型国产橡木制品对葡萄酒陈酿香气的影响

采用顶空固相微萃取与气相色谱-质谱联用技术,检测蒙古栎制成的橡木片和橡木板陈酿的葡萄酒中主要陈酿香气成分的变化。结果表明:在90 d的陈酿过程中,糠醛和5-甲基糠醛含量在陈酿10至20 d即可达到最高值,此后其含量快速减少;愈创木酚和甲基愈创木酚含量则在陈酿20 d达到最高值以后,基本保持不变;顺式和反式橡木内酯含量在整个陈酿过程中一直呈增加趋势;而香草醛含量在采用橡木片和橡木板陈酿的葡萄酒中,具有不同的变化趋势:橡木片陈酿的葡萄酒,香草醛含量在30d时即达到最高值,此后逐渐减少,而橡木板陈酿的葡萄酒,香草醛含量在90 d的陈酿过程中一直增加;乙基愈创木酚和乙基苯酚含量仅在陈酿30和60 d后才显著增加。橡木片和橡木板陈酿的葡萄酒之间,除乙基苯酚和乙基愈创木酚含量无显著差异外,糠醛、香草醛、愈创木酚和橡木内酯的含量均具有显著差异,表明橡木制品的类型对葡萄酒的陈酿香气具有重要影响。      

Differences in the phenolic composition and sensory profile between red wines aged in oak barrels and wines aged with oak chips

The aim of this study was to evaluate the similarities or differences in the phenolic composition and the sensory characteristics between wines traditionally aged in new French and American barrels for different periods of time, and wines aged for 30 days with different kinds (different geographical origin al toasting degree) of oak chips. This study was carried out with two grape varieties, Mencía and Tinta del País, and in two consecutive vintages. The results obtained indicated that it was not possible to obtain wines aged with chips with sensory characteristics similar to those aged for a long time in new barrels, independently. However, the results showed that the use of oak chips could be a good alternative for elaborating young wines with slight olfactory and gustative wood notes quite similar to wines aged in new barrels for short periods of time (about three months).     

烘烤强度和木纹理对橡木（Quercus petraea）心材多酚和香气的影响

考察不同烘烤程度对不同纹理橡木心材试样中低分子质量酚酸和挥发性物质含量的影响,结果表明烘烤过程将会改变橡木心材的物质组成,并通过相应的化学反应增加挥发性物质的含量。同时,在不考虑烘烤强度条件下,供试的细纹理橡木心材试样含有较高的挥发性物质含量,例如顺/反橡木内脂、顺/反异丁子香酚、呋喃醛、紫丁香醇,以及芥子醛、松柏醛、香草醛和丁香醛等低分子质量酚类化合物,而中纹理和粗纹理的样品则表现出较高的总酚、总单宁水平,以及较高的鞣花酸和没食子酸含量。此外,主成分分析显示,中纹理和细纹理样品的中度和重度烘烤处理与橡木心材试样的挥发性物质含量有较大的正相关性,而粗纹理的未烘烤和轻度烘烤样品则与试样中总单宁和阿魏酸含量呈正相关。     

Criteria to discriminate between wines aged in oak barrels and macerated with oak fragments

Wine aging in barrels is carried out to increase stability and achieve more complex aromas. In the last few years, however, the practice of macerating wine with small fragments of toasted oak (chips) has become increasingly common. This conveys similar tastes, aromas, and wooden notes to the wine as those obtained with traditional barrel aging, but much faster and at a fraction of the cost. Without proper regulation, this could lead to fraud if wine macerated with chips is offered as barrel aged wine.In the present study, 75 volatile compounds have been determined by applying gas chromatography–mass spectrometry (MS) and flame ionization detection (FID). It has been found that compounds directly related to the wood have greater discriminative power for telling apart wines aged in barrels from those macerated with oak fragments, but no single compound permits flawless classification. Therefore, we have studied the effect of the addition of oak fragments of different origins, different oak types, different formats and subjected to different toasting processes on a set of 231 samples from 6 Spanish Denominations of Origin wines (DOs), and compared them to those same wines aged in oak barrels. In light of the results, we have developed a set of criteria which allows distinguishing with high degree of accuracy between wines which have been aged in barrels and those macerated with oak fragments. The application of these criteria to different wines allows correct classification in over 90% of cases.     

Influence of Oak Chips Geographical Origin,Toast Level,Dosage and Aging Time on Volatile Compounds of Apple Cider

The effects of different geographical origin, levels of toasting, dosage and the aging time of oak chips on volatile compounds released into ciders were studied. The oak chips tested were the same size and with three different toast levels (light, medium and heavy) from French, American and Chinese oak. The oak wood chips were immersed in identical ciders. Higher alcohols, acids and esters were determined by headspace (HS)–solid phase microextraction (SPME) and gas chromatography (GC)–mass spectrometry (MS), while oak‐related aroma compounds including trans‐and cis‐oak lactones, guaiacol, 4‐methylguaiacol, furfural, 5‐methylfurfural, vanillin, eugenol and isoeugenol, were determined by liquid‐liquid extraction by means of ultrasound and GC/MS selective ion monitoring (SIM). The results showed that there was little difference between the oak‐related volatile compositions of ciders aged with French oak chips and those aged with American oak chips, but that there were obvious differences with Chinese oak chips. It was observed that oak chips, at medium toasting levels, released the highest concentrations of volatile components into the ciders. Most of the oak‐related volatile aroma compounds extracted had an increase that depended on the oak chip dosage with the exception of guaiacol and furfural.     

Statistical differentiation of wines of different geographic origin and aged in barrel according to some volatile components and ethylphenols

The purpose of this paper was to study the effect of wine composition and geographical origin on the accumulation of volatile compounds in barrel-aged wines. Therefore, 267 wines belonging to different origin appellations were analysed. In order to analyse the data, a multivariate statistical technique was applied, that can be quite useful in creating an overall view of the problem in which multiple variables are analysed. Statistical analysis gave four significant factors, accounting for 84.12% of the variance. These factors summarise the information of a group of variables closely correlated to each other. Factor 1 grouped together oak lactones and eugenol, so it was associated with oak barrel type and with toasting of barrels. Factor 2 was associated with ethylphenols, related to wine quality diminution. Factor 3 grouped together guaiacol, furfural, and 5-methylfurfural, and was thus associated with wood thermal degradation; factor 4 was associated with the cis/trans ratio, related to oak origin. Whereas geographical origin of wines affected the accumulation of volatile compounds, the cis/trans ratio was only affected by oak barrel type. Among the tested parameters, alcoholic degree was the enological parameter that had the greatest effect on the accumulation of volatile compounds in wines. Oak lactones were the compounds that were present in all wines, so they could be used as oak ageing indicators.     

Enological potential of chestnut wood for aging Tempranillo wines Part II: Phenolic compounds and chromatic characteristics

The behavior of different aging chestnut treatments (chips, barrels, toasting process, and aging time) on the phenolic profile and color characteristics of Tempranillo red wines has been evaluated. Chestnut treatment produced a considerable decrease of anthocyanic phenolic compounds and an increase of benzoic acids in aged wines. In contrast, the effect of toasting process was not very significant on the phenolic composition of aged wines. Meanwhile the effect of time was a crucial parameter regarding the pyranoanthocyanin and flavonol content, attributable not only to the slow evolution and transformation of wine phenolic compounds, but also to the micro oxygenation process suffered through the pores of barrels over the aging time. Results also strongly suggested that with the use of chestnut chips a considerable sorption effect of free flavanols was observed. All these modifications were reflected on the chromatic characteristics of aged wines.     

The effects of size, temperature and air contact on the outcome of heating oak fragments

The concentrations of the important oak aroma volatiles guaiacol, 4-methylguaiacol cis - and trans -oak lactone and vanillin in extracts of French and American oak heated under various conditions were measured using stable isotope dilution analyses coupled with gas chromatography-mass spectrometry. Heating resulted in marked increases in the concentrations of guaiacol, 4-methylguaiacol and vanillin, with more formed at higher temperature. Approximately twice as much guaiacol and 4-methylguaiacol and two to five times as much vanillin were formed by heating in the presence of air compared to heating under argon. Oak lactone concentration was less affected by heating. The effects of heating different sized oak pieces were investigated for French and American oak samples. Compared to heating larger oak pieces, heating smaller fragments of oak generated up to twice as much guaiacol and 4-methylguaiacol and two to four times as much vanillin at 235^oC for both French and American oak. This effect is ascribed to the exposure of a greater surface area of oak to air when smaller fragments are heated. Variable effects were observed for cis - and trans -oak lactone. Variation in chip size, as well as heating time and temperature, is clearly one way of obtaining different aroma profiles from oak products.     

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.     

Antioxidant capacity, scavenger activity, and ellagitannins content from commercial oak pieces used in winemaking

In 2005, the European Union authorized the use of oak wood pieces in winemaking, and consequently, the addition of oak chips has been generalized. Thus, the antioxidant capacity, scavenger activity, and ellagitannins content from fourteen different commercial oak wood pieces (Quercus spp.) that can be found on the Portuguese market as alternatives to barrels for aging wines were studied. Commercial oak wood pieces samples from Quercus petraea had significantly higher antioxidant activity values than the pieces from Quercus alba species. In general, antioxidant capacity and scavenging activity decrease with the toasting level of the oak wood pieces samples analyzed. A similar effect was detected in the individual ellagitannin content studied. On the other hand, with the toasting process, the total phenolic content and the ellagic acid concentration increased. Finally, a correlation analysis revealed that ellagitannins contribute to the antioxidant capacity of oak wood pieces studied. From the data presented in this paper, antioxidant capacity and ellagitannin content of the oak wood pieces studied have been clearly related either to the oak wood species used, particle size, or to toasting levels.     

Changes in the concentration of volatile oak compounds and esters in red wine stored for 18 months in re-used French oak barrels

Studies were made of changes in concentration of oak-wood-derived volatiles and the evolution of esters in red wine during storage in twice-used French oak barrels. Wine samples were taken after 8, 10, 12, 15, and 18 months maturation in the barrels. Results showed that most of the volatile compounds extracted from the wood (furanic compounds, volatile phenols, lactones) reached maximum concentration between 10 and 12 months of barrel storage. After 18 months of maturation many of the compounds showed concentrations similar to those found after 10 to 12 months. However, the concentrations of furfural, 5-methyl furfural, furfuryl alcohol, coniferaldehyde, acetovanillone and phenol in wines aged for 18 months were lower than those reached after 10 to 12 months. The concentration of the ethylphenols increased right up to 18 months of ageing, which can only have a negative impact on the quality of the wine. There were few modifications in the concentration of esters, except for ethyl lactate which reached peak concentration after 12 months maturation and decreased thereafter.     

The effect of oak wood source, location of seasoning and coopering on the composition of volatile compounds in oak-matured wines

The effect of geographical origin and place of seasoning and coopering of oakwood on the concentration of 20 compounds extracted into, or formed in, Chardonnay, Cabernet Sauvignon and model wines during barrel maturation is described. The oak from which the barrels were fabricated was sourced from the Vosges and Limousin regions and the Tronçais forest in France, and from Ohio in the USA, and was seasoned in either Australia, France or the USA. Wines matured in Vosges oak barrels contained the highest concentrations of cis and trans- oak lactone and eugenol. The Limousin oak barrels imparted lower levels of cis- oak lactone and eugenol to the wines than did the other French oaks. However, the Limousin-oaked wines were richer in these compounds than the American-oaked wines. These results reflected the previously reported composition profiles of the oak-wood from which the barrels were fabricated. Oak seasoned and coopered in Australia generally imparted more cis- oak lactone, eugenol and the coopering products vanillin and furfural into the wines than did the oak seasoned in France or the USA. Although medium toast had been specified for all barrels, there was considerable variability in the concentration of compounds formed by coopering in the wines. Apparent random microbiological activity in the wines also contributed substantially to variation in wine composition. As a likely result of coopering and microbiological variability, few consistent origin or seasoning effects on the compounds resulting from coopering or microbiological action during oak maturation were observed.     

Volatile composition and sensory characteristics of Chardonnay wines treated with American and Hungarian oak chips

Toasted or non-toasted chips of oak woods of different geographical provenances were macerated in Chardonnay wines (4 g/l) during a period of 25 days. Oak lactones were detected in significant quantities in wines treated with American oak. Only trace amounts of oak lactones were detected in the wines treated with Hungarian oak. Toasting of the oaks increased the quantities of the compounds derived from the thermal degradation of lignin: vanillin, eugenol, guaiacol and its derivatives and the pyrolysis of cellulose and hemicellulose: furfural and 5-methyl furfural, and decreased the concentrations of the two isomers of oak lactones. The concentrations of the majority of the volatile compounds did not present statistically significant differences between 15 and 25 days. However, the wines preferred by the tasters and with maximum intensity of the sensory attributes acquired were those treated with oak chips for 25 days. Chemical and sensorial analyses of wines revealed that the effect of the toasting of oak chips on wine characteristics was greater than the type of oak used. All wines studied were positively evaluated by the panellists.     

Changes in contents of phenolic compounds during maturing of barrique red wines

Concentrations of derivatives of benzoic and cinnamic acids and furaldehyde were studied during maturing of a red wine (a mixture of Cabernet Sauvignon and Merlot) in barrique barrels (Quercus robur). Samples were taken at three-week intervals over 6 months. The influence of degree of toasting of the wood on the amount of phenolic compounds in barrique wine was also investigated. The samples were pre-separated using a solid-phase extraction on an RP 105 polymeric sorbent and analysed by high-performance liquid chromatography with UV-DAD detection. Gallic, protocatechuic, p-hydroxybenzoic, vanillic, caffeic, syringic, p-coumaric, ferulic, benzoic and ellagic acids and p-hydroxybenzaldehyde, vanillin, 2-furaldehyde, 5-methoxy-2-furaldehyde and 5-methyl-2-furaldehyde were identified in the extracts of natural and toasted wood chips and in the extracts of the wine. Syringaldehyde was identified only in the extracts of the toasted wood chips. Ellagic acid can be regarded as a characteristic compound of barrique wine ageing and its constant level during some periods could become a marker of maturity of barrique wines. Due to the absence of furaldehydes in natural wines, these compounds can be considered as typical components of barrique wines and so they can serve as a marker of authenticity of barrique wines.     

Influence of the botanical origin and toasting level on the ellagitannin content of wines aged in new and used oak barrels

The influence of the botanical origin (French oak: Quercus petraea and American oak: Quercus alba) and different toasting levels (light, medium and heavy) on the ellagitannin content of wines aged in oak barrels has been studied. This took place in two consecutive vintages in order to study what happens after the barrels have been already used for one year with another wine. This study was carried out with two red wines (Cabernet Sauvignon) and with two decolored white wines (Macabeo) from vintages 2012 and 2013 in order to work with a simpler matrix which facilitates chemical analysis. The results show that the botanical origin, toasting level and the number of times that the barrels have been used exert a major influence on the final ellagitannin concentration. In general, the behavior of all the individual ellagitannins was very similar to that described for the total ellagitannins. Briefly, the levels of total ellagitannins concentration in the decolored white wine aged for 12 months in new French barrels ranged between 31.2 mg/L in the lightly toasted and 4.7 mg/L in the heavy toasted. In contrast, these levels were quite lower in American new barrels ranging between 3.6 mg/L and 0.9 mg/L. Finally, the total ellagitannin concentration decreased an average of 63% in the wines aged in the one year used barrels.