Volatile composition of Mencı́a wines

Monovarietal Mencı́a wines from two different Appellation of Origin Controlled (AOC) of Galicia (NW Spain) were analyzed. The content of some varietal and fermentative volatile compounds was determined by gas-chromatography and GC–mass spectrometry. These red wines, independently of their origin, showed terpene profiles, that were typical of their varietal characteristics with an important contribution of linalool, citronellol, α-pinene and β-pinene. Other important varietal compounds were: norisoprenoids (α- and β-ionone, and theaspirane), phenyl-ethanol and benzyl alcohol. The 67 analytical variables were submitted to analysis of variance, and the results showed that only nine volatile compounds were significantly different (p<0.05) among the two AOC (trans-3-hexenol, 1-butanol, isobutanol, ethyl acetate, hexyl acetate, butyric acid, γ-butyrolactone, methionol, and N-(2-hydroxy-ethyl)-acetamide). Principal component analysis showed the differentiation of wines according to geographical areas.     

Influence of deficit irrigation and kaolin particle film on grape composition and volatile compounds in Merlot grape (Vitis vinifera L.)

The effect of deficit irrigation and a kaolin-based, foliar reflectant particle film (PF) on grape composition and volatile compounds in Merlot grapes was investigated over two growing seasons in semi-arid, south-western Idaho. Vines were provided with differential amounts of water based on their estimated crop evapotranspiration (ET_c) throughout berry development, and particle film was applied to half of the vines in each irrigation main plot. Free and bound volatile compounds in grapes were analyzed using stir bar sorptive extraction–gas chromatography–mass spectrometry (SBSE–GC–MS). The concentrations of free C₆ compounds (hexanal, trans-2-hexenal, and 1-hexanol) decreased, and bound terpene alcohols (nerol and geraniol) and C₁₃-norisoprenoids (β-damascenone, 3-hydroxy-β-damascenone, 1,1,6-trimethyl-1,2-dihydronaphthalene, and 3-oxo-α-ionol) increased in berries each year in response to severity of vine water stress. Concentrations of C₁₃-norisoprenoids and bound forms of nerol and geraniol were positively correlated with their concentrations in the corresponding wines. Particle film application had minimum effect on free and bound volatile composition in the grapes, and there was no interactive effect between particle film and deficit irrigation. However, particle film application enhanced the total amount of berry anthocyanins.     

Comparison of major volatile compounds from Riesling and Cabernet Sauvignon grapes (Vitis vinifera L.) from fruitset to harvest

Background and Aims: Research on concentration changes of volatile compounds during grape physiological development has focused on the period from veraison to harvest. This study compared the developmental changes in the major volatile compounds released after the crushing of Riesling and Cabernet Sauvignon grapes sampled from fruitset to harvest during the 2007–2008 season. Methods and Results: Volatile compounds were extracted from the headspace of crushed Riesling and Cabernet Sauvignon grapes sampled throughout berry development using solid-phase microextraction and analysed by gas chromatography–mass spectrometry. A multivariate statistical approach coupled with analysis of variance was applied to compare the developmental changes in volatile compounds for the two cultivars. In both cultivars, E-2-hexenal was the most abundant volatile compound, and it showed a significant increase in concentration after veraison. Benzene derivatives discriminated ripe Cabernet Sauvignon grapes, whereas monoterpenes and sesquiterpenes discriminated both cultivars pre-veraison with a broader range of terpenes observed in the Cabernet Sauvignon samples compared with the Riesling samples. At veraison, terpene production in both varieties was low, but Riesling grapes produced some terpenes (geraniol and α-muurolene) post-veraison. Generally, esters and aldehydes were the major class of compounds from Riesling grapes, while Cabernet Sauvignon showed a greater tendency to form alcohols. Conclusions: Both Riesling and Cabernet Sauvignon grapes had a more complex volatile compound composition pre-veraison than post-veraison. This study suggests that some compounds that contribute to grape aroma may be produced pre-veraison, and not simply accumulate after veraison. Significance of the Study: Understanding the timing of volatile compound production and cultivar differences will guide viticulture researchers and growers in the optimisation of vineyard strategies to enhance grape aroma attributes that may, in turn, contribute to wine aroma.     

Effect of ammonium nitrogen supplementation of grape juice on wine volatiles and non-volatiles composition of the aromatic grape variety Albariño

Vitis vinifera cv. Albariño is an aromatic variety characterised by terpenes present largely as glycosidic flavour precursor compounds, which depends on fermentation to reveal its aromatic varietal potential. Clarified Albariño must containing 250 mg N/L (control) was supplemented with diammonium phosphate to 350 and 450 mg N/L before fermentation with a high-nitrogen-demand wine strain of Saccharomyces cerevisiae (M05). Ammonium supplementation had a significant effect on the chemical composition (titratable acidity and ethanol) and volatile profile of Albariño wines. Varietal compounds in the free fraction (limonene, linalool, α-terpineol, α-ionone and β-damascenone) and bound (limonene, linalool and α-terpineol), as well as most yeast-derived fermentation products (including esters, higher alcohols and volatile acids) were associated with moderate nitrogen concentrations. Free β-ionone, bound geraniol, bound α-ionone, bound β-damascenone and 1-hexanol were associated with high nitrogen concentrations. OAV wines made with moderate nitrogen exhibited a higher total odorant activity, driven by ethyl esters, terpenes and C₁₃-norisoprenoids, resulting in fruity and floral aroma attributes.     

Aromatic composition of the Vitis vinifera grape Albariño

The Vitis vinifera Albariño is a considerably acid white Galician variety, with an important aromatic potential. The composition of the grape at the harvest date during four consecutive years is reflected in this paper. The normal parameters of total acidity, pH, and sugar and malic acid contents, were determined according to the official methods of the OIV. Aromatic compounds extracted from the grape sample using C18 cartridges were identified and quantified by gas chromatography/mass spectrometry. The results obtained demonstrate a high content of bound form aromatic compounds and that, of the responsible compounds for the varietal aroma, linalool, geraniol, benzyl alcohol and 2-phenylethanol predominate. This supports the observation of the floral character of the variety.     

安吉白茶挥发性成分及关键呈香成分分析

采用搅拌棒吸附萃取结合气相色谱-质谱联用技术研究安吉白茶的挥发性成分组成特点,并利用气相色谱-嗅闻-质谱技术结合相对气味活性值分析了安吉白茶的关键呈香成分。结果表明,在20 个安吉白茶样品中共检测到109 种挥发性成分,其中含量最高的成分有香叶醇、邻苯二甲酸二异丁酯、植醇、水杨酸甲酯、顺式茉莉酮、亚麻酸、芳樟醇等;不同等级安吉白茶的挥发性成分含量存在较大差异;此外,基于34 个共有特征峰,建立安吉白茶挥发性成分指纹图谱;16 种化合物被鉴定为安吉白茶的关键呈香成分,包括反式-β-紫罗兰酮、香叶醇、芳樟醇、己醛、庚醛、(E)-2-庚烯醛、α-紫罗兰酮和(Z)-己酸-3-己烯酯等。     

Comparison of black tea aromas of orthodox and CTC tea and of black teas made from different varieties

Volatile compounds obtained from orthodox black tea and CTC tea were analysed by a g.c.-m.s. method. A difference in the contents of cis-3-hexenol, linalool, linalool oxides, methylsalcylate and geraniol was found between the two types of tea. It was thought that the difference in the contents of volatile compounds might be produced by the individual manufacturing processes. A typical difference in the contents of linalool and geraniol was observed in volatile oils of black teas made from cultivars of v. assamica and hybrids of assamica and sinensis. The difference in the volatile compounds in black teas may be related to the genetic variation.     

Contribution of free and glycosidically-bound volatile compounds to the aroma of muscat “a petit grains” wines and effect of skin contact

Free and glycosidically-bound volatile compounds of must, skin and wine from Muscat “a petit grains” cultivated in Spain were determined, and the effect of different skin contact times on the aroma composition and sensory characteristics of wines was investigated. Must and wine had a large quantity of mono-terpenes, mainly linalool, geraniol, and nerol. The most abundant glycosylated fraction was the mono and poly-oxygenated terpenes, followed by benzene compounds and norisoprenoids. Must skin contact at 18 °C during 15 and 23 h produced an important increase in the free and bound varietal compounds, which suggests the use of glycosidic enzymes, together with skin maceration, to increase wine aroma. From a sensory standpoint, must skin contact was very positive, since it brought about an increase in the fresh and fruity characteristic of the wines, and they also had more body.     

Bound aroma compounds of Gual and Listán blanco grape varieties and their influence in the elaborated wines

Listán blanco and Gual are two white grape varieties grown in Spain (Canary Islands) and Gual is also grown in Portugal (Madeira Island). Wine quality could be improved by exploiting the varietal characteristics present in grapes as aroma precursors. At the present time, the enologic potential of these varieties has not yet been studied. Aroma precursors in musts and skins, and free volatiles in wines were determined in samples of both varieties. Aroma precursors of must and skins were isolated by absorption on XAD-2 resin and the aglycone liberated by means of acid hydrolysis. Free volatiles from wines and from aroma precursors were extracted with dichloromethane and then analysed by gas chromatography-mass spectrometry (GC–MS). Among the aroma precursors analysed, only α-terpineol, linalool and linalool oxides, 4-allyl-2,6-dimethoxyphenol, 2-methoxy-4-vinylphenol, 4-hydroxybenzaldehyde, vanillin and benzyl alcohol showed contents in grapes comparable to the levels observed in wine volatile compounds.     

Phenolic Substances,Flavor Compounds,and Textural Properties of Three Native Romanian Wine Grape Varieties

In this work, the chemical compositions and texture characteristics of three native Romanian wine grape varieties (Feteasc? regal?, Feteasc? alba, and Feteasc? neagr?) were studied. We assessed the distinct characteristics directly linked to their phenolic compositions, volatile profiles, and mechanical properties and compared these characteristics with those of Pinot noir grapes. The effect of the growing zone was also evaluated. Various spectrophotometric indices directly related to the phenolic compositions of berry skins and seeds were determined. The detailed phenolic compositions (anthocyanins, hydroxycinnamoyl tartaric acids, and stilbenes) of the skins were determined using high-performance liquid chromatography methods. Free and bound volatile compounds in the berries were quantified by gas chromatography/mass spectrometry. The textural properties of the skins and seeds were measured by instrumental texture analysis. The results showed high diversity among the varieties and zones that affected the enological potential. Among the white varieties, Feteasc? alb? grapes could be less susceptible to browning as a consequence of their lower trans-caffeoyltartaric acid concentration, whereas Feteasc? regal? grapes from Cluj had the highest concentrations of total free and bound volatile compounds, particularly terpenes and norisoprenoids. Among the red varieties, Feteasc? neagr? was identified as a promising variety to be exploited in the future for its particular phenolic characteristics, particularly those grapes grown in Mica. Nevertheless, Feteasc? neagr? grapes grown in Cluj had the highest total glycosidically bound terpene concentrations. Finally, differences in the mechanical and/or acoustic properties of the skins and seeds could strongly influence the kinetics and completeness of phenolic compound extractions.     

Biotransformation of monoterpene alcohols by Saccharomyces cerevisiae, Torulaspora delbrueckii and Kluyveromyces lactis

Monoterpenoids are important flavour compounds produced by many plant species, including grapes (Vitis vinifera) and hops (Humulus lupulus). Biotransformation reactions involving monoterpenoids have been characterized in filamentous fungi, but few examples have been observed in yeasts. As monoterpenoids are in contact with yeasts during beer and wine production, biotransformation reactions may occur during the fermentation of these beverages. This paper describes the biotransformation of monoterpene alcohols, of significance in the alcoholic beverage industries, by three yeast species. All three species analysed had the ability to convert monoterpenoids. Saccharomyces cerevisiae and Kluyveromyces lactis reduced geraniol into citronellol, whilst all three yeasts produced linalool from both geraniol and nerol. Monocyclic alpha-terpineol was formed from both linalool and nerol, by all three yeasts. alpha-Terpineol was then converted into the diol cis-terpin hydrate. K. lactis and Torulaspora delbrueckii also had the ability to form geraniol from nerol. Finally, the stereospecificity of terpenoid formation was analysed. Both (+) and (-) enantiomers of linalool and alpha-terpineol were formed in roughly equal quantities, from either geraniol or nerol.     

超临界CO_2萃取柚子叶、花精油的GC-MS分析

采用超临界CO2萃取技术提取柚子叶、花中的精油,运用气相色谱-质谱(GC-MS)联用技术对其化学成分进行分离和鉴定,并用峰面积归一化法确定各组分的相对含量。结果表明:从柚子叶精油中分离出61个色谱峰,鉴定出39个化合物,占总离子峰相对含量的90.05%。其主要化学成分有匙叶桉油烯醇(21.36%),石竹烯氧化物(17.16%),β-石竹烯(8.40%),α-石竹烯(2.07%),异芳萜烯氧化物(2.01%)等。从柚子花精油中分离出42个色谱峰,鉴定出27个化合物,占总离子峰相对含量的89.31%。其主要化学成分有金合欢醇(19.02%)、橙花叔醇(18.24%),龙脑(6.60%),芳樟醇(4.03%),橙花醇(2.57%)等。柚子叶与柚子花精油共同鉴定出的化合物有橙花醇、香叶醇、香叶酸、β-石竹烯等12种,其相对含量存在不同程度差异。     

Determination of volatile compounds in apple pomace by stir bar sorptive extraction and gas chromatography-mass spectrometry (SBSE-GC-MS)

A method based on stir bar sorptive extraction combined with gas chromatography-mass spectrometry detection (SBSE-GC-MS) has been optimized with the aim of applying it to the analysis of apple pomace. The method allowed the identification of 124 volatile compounds after 3 h of extraction with a precision (RSDs) ranging between 2% (linalool) and 11% (ethyl hexanoate). Its use in analyzing varietal apple pomace revealed the interest of this substrate as regards its content in aromas. From a semi-quantitative point of view, the higher content in aldehydes and esters of the Blanquina variety is worth highlighting, as are the greater concentration of acids in the Clara variety and the higher content of terpenes and norisoprenoides in the Coloradona variety. In contrast, the Ernestina and Perico varieties presented the lowest levels of aromas. PRACTICAL APPLICATION: The analysis of varietal apple pomaces showed the importance of this type of waste in the food industry, both for its content in aromas such as for its use as substrate in biotechnological processes.     

HS-SPME-GC-MS法分析栽培架式对威代尔葡萄果实香气的影响

采用顶空固相微萃取结合气相色谱-质谱联用技术对棚架与篱架架式下栽培的威代尔葡萄香气成分进行鉴定分析。应用热图、偏最小二乘判别分析、香气雷达图分析方法探究不同栽培架式对葡萄果实香气的影响。研究表明,葡萄果实定性确定87 种香气物质。对于2 种架式,高级醇类、C6类香气化合物在葡萄果实香气化合物总含量的贡献率很高,而萜烯类化合物在棚架贡献率很少,在篱架贡献率高居首位;果实香气活性值贡献方面则主要由高级醇类、萜烯类、C6、C9类香气化合物组成,棚架侧重于C9类香气化合物,而篱架侧重于萜烯类香气化合物。对葡萄果实香气有整体贡献（香气活性值＞1）的香气化合物共计24 种,其中绝大多数香气物质均呈现后熟期含量逐渐升高的规律,并且架式对比得出有18 种物质在篱架含量更高。香气雷达图显示威代尔葡萄果实最突出的香气特征是青草香、花香、果香,且篱架均优于棚架。综上所述,在东北桓仁地区,相比于棚架栽培,篱架栽培方式是更适合进行威代尔葡萄栽培的架式选择。     

Predication of Japanese green tea (Sen-cha) ranking by volatile profiling using gas chromatography mass spectrometry and multivariate analysis

The sensory quality ranking of Japanese green tea (Sen-cha) was evaluated and predicted using volatile profiling and multivariate data analyses. The volatile constituents were extracted from tea infusion using vacuum hydrodistillation and analyzed using GC/MS. A quality of green tea could be discriminated to a high or low grade regarding the volatile profile by partial least squares discriminant analysis (PLS–DA). A quality ranking predictive model was developed from the relationship between subjective attributes (sensory quality ranking) and objective attributes (volatile profile) using partial least squares projections to latent structures together with the preprocessing filtering technique, orthogonal signal correction (OSC). Several volatile compounds highly contributed to model prediction were identified as various odor-active compounds, including geraniol, indole, linalool, cis-jasmone, dihydroactinidiolide, 6-chloroindole, methyl jasmonate, coumarin, trans-geranylacetone, linalool oxides, 5,6-epoxy-β-ionone, phytol, and phenylethyl alcohol. The whole fingerprints of these volatile compounds could be possible markers for the overall quality evaluation of green tea beverage.     

Thienyl analogues of acyclic monoterpene alcohols and their biological activity

BACKGROUND: Thienyl analogues of linalool, geraniol, nerol and citronellol were synthesised and their sensory and anti‐ microbial activities were investigated. RESULTS: The thienyl analogues of linalool, geraniol, nerol and citronellol, in which the isobutenyl moiety was replaced by a thiophene substituent, were synthesised from commercially available 2‐ and 3‐methylthiophenes and 2‐ and 3‐thiophenecarboxaldehydes. The olfactory properties of the new compounds were generally of the corresponding parent terpene type; however, their relative volatility determined by the headspace gas chromatography method was lower by a factor of 34–42 compared with the parent alcohols. Antimicrobial activity against Aspergillus niger and Penicillium expansum of some thienyl analogues of linalool was 1.5–3 times higher than that of linalool, with a minimum inhibitory concentration of 0.2–0.1 µL mL^?1. CONCLUSION: Replacement of the isobutenyl moiety in acyclic monoterpene alcohols by a thienyl substituent results in the formation of new terpene analogues, some of which are interesting for perfumery and cosmetology because of their odour quality, tenacity and antimicrobial action. Copyright © 2009 Society of Chemical Industry     

酿酒葡萄新品系‘黑珍珠’果实品质分析

为了研究‘黑珍珠’葡萄果实的酿酒特性,探究其亲本信息,分别利用高效液相色谱-质谱（high performance liquid chromatography-mass spectrometry,HPLC-MS）和气相色谱-质谱（gas chromatography-mass spectrometer,GC-MS）技术分析了‘黑珍珠’葡萄果实的花色苷和香气化合物的组成及含量。HPLC-MS分析结果表明,‘黑珍珠’葡萄果皮中花色苷总量为2 774.76 mg/kg mf,以花色素双葡萄糖苷为主（71.2%）,推测其含有非欧亚种葡萄的血缘。GC-MS分析结果表明,‘黑珍珠’葡萄果实香气化合物以游离态与糖苷结合态形式存在,共检测到123 种化合物。简单序列重复分析结果表明,在供试品种（‘贝达’、‘烟73’和‘Kolor’）中未发现‘黑珍珠’的亲本。由于‘黑珍珠’果皮花色苷的种类与含量丰富,且其单品种葡萄酒颜色深,未来可以作为酿造具有地区特色红葡萄酒的新品种或调色新品种。     

Glycosidic aroma compounds of some Portuguese grape cultivars

In order to evaluate the potential aroma of some Portuguese grapes, several glycosidically bound aroma compounds of ten grape varieties grown in Évora, Alentejo, Portugal, were released, identified and quantified using gas chromatography–mass spectrophotometry. White varieties were Arinto, Perrum, Rabo‐de‐Ovelha, Roupeiro and Antão Vaz. Red varieties were Trincadeira, Aragonez, Tinta Caiada, Moreto and Castelão. Grapes of Roupeiro and Trincadeira from five other vines in the Alentejo region were also studied. For each variety pulp and skin were analyzed separately. The compounds produced by enzymatic hydrolysis of glycoside precursors extracted from pulps and skins of these grapes were similar to the ones appearing in the so‐called ‘aromatic’ varieties; however, the amounts found were significantly lower. These results seem to show the neutral characteristic of these grapes to indicate that each variety has a distinctive profile regarding compounds from the linalool class. The ratios of trans : cis forms of some linalool compounds remain the same in all samples of Roupeiro and Trincadeira, regardless their origin. In Trincadeira grapes no linalool was detected. Skins are always richer than pulps. The acid hydrolysis of norisoprenoid aglycons produced highly odorant compounds previously described in grape varieties. Although some differences between varieties could be detected, the red grapes Aragonez and Castelão are richer in vitispiranes while Moreto, Trincadeira and Tinta Caiada are richer in actinidols; in white grapes, only Roupeiro and Perrum show detectable amounts of vitispiranes. These results need further investigation and analysis to be considered as a statement and should be confirmed in an extended study. Copyright © 2006 Society of Chemical Industry