Interactions of phenolic and volatile compounds with yeast lees,commercial yeast derivatives and non toasted chips in model solutions and young red wines

Ageing of wines on lees, the use of commercial yeast derivative products and the addition of oak chips to wine permit the release of different compounds such as mannoproteins and polysaccharides into wines during yeast autolysis. These compounds released can interact with phenolic compounds and/or aromatic compounds, also modifying wine sensory perception. For that reason, the aim of this work was to evaluate the interaction of phenolic and volatile compounds of wines with yeast lees, non-toasted oak wood chips and different commercial yeast derivative preparations in model wine solutions and in a real red wine. The results found in this study have shown that most of the phenolic and volatile compounds studied are adsorbed by wood and bound by lees in model wine solutions. However, in the model wines in general, the commercial yeast derivative products studied only interacted with the volatile compounds but not with the phenolic compounds. The adsorption of the phenolic compounds occurred in the first 15 days of treatment, remaining constant for 2 months; however, in the case of volatile compounds, these compounds initially displayed a retention effect, but after 30–60 days, the release of the previously bound compounds was instigated. The adsorption effect on the phenolic and volatile compounds in the model wine solution was not always the same as in the red wine studied, which highlights the important presence of other wine compounds in these interactions.     

Yeast derivatives (extracts and autolysates) in winemaking: Release of volatile compounds and effects on wine aroma volatility

A qualitative study of volatile compounds in three commercial yeast extracts and autolysates was performed by solid-phase microextraction-gas chromatography with mass spectrometric and olfactometric detection; their addition to white wines and their effect on wine aroma composition were investigated by analytical, olfactometric and sensory evaluations. More than 160 volatile compounds were detected in the headspace of the commercial powders (some not previously reported in literature), and their olfactory characters were described. Yeast derivatives strongly modified wine aroma composition, either affecting the volatility of wine aroma compounds or by releasing exogenous volatiles. Dosage appeared to be fundamental: low amounts increased the volatility of some esters, giving more flowery and fruity notes to the wine; higher amounts increased fatty acid content in the wine headspace, producing yeasty, herbaceous and cheese-like smells. Sensory tests demonstrated that yeast derivatives would not be suitable for wines with a typical varietal aroma.     

Volatile profile and potential of inactive dry yeast‐based winemaking additives to modify the volatile composition of wines

BACKGROUND: With the objective of determining the potential of winemaking additives based on inactive dry yeast (IDY) to modify the volatile composition of wines, gas chromatography coupled to mass spectrometry was employed to characterize the volatile profile of a widely used IDY preparation. To have the most accurate picture of the volatile compounds, pressurized liquid extraction technique (PLE) was used with different solvents and extraction temperatures. Complementary headspace solid‐phase microextraction was applied to gain insight into the volatile composition. In addition, the ability of some target volatile (pyrazines) to be released into model wines was investigated. RESULTS: The PLE technique was mainly suitable for the extraction of volatile compounds with a low to medium molecular weight and the best extraction yields were obtained by using apolar solvents (hexane) and high temperatures (150 °C). PLE in combination with solid‐phase microextraction allowed the identification of 35 volatile compounds, most of them heterocyclic‐containing nitrogen compounds formed during the processing of IDY that could be released into the wines: the signal of four target masses corresponding to 2,5‐dimethylpyrazine, trimethylpyrazine, methylbutylpyrazine and 2‐ethyl‐3,5‐dimethylpyrazine increased in the synthetic wines after 13 days when IDY was left in the model wines. CONCLUSION: The study confirmed that some volatile compounds identified in IDY which were formed during processing could be released into the wines which might modify wine aroma composition. Copyright © 2009 Society of Chemical Industry     

不同酵母发酵的赤霞珠干红葡萄酒香气成分研究

运用顶空固相微萃取和气相色谱- 质谱- 计算机联机分析,以不同酵母发酵的赤霞珠干红葡萄原酒为原料,采用计算机谱图库检索定性的方法,对三种不同酵母发酵的葡萄酒的主要香气成分进行分析,共检测出65 种化合物。结果表明：赤霞珠葡萄酒中的香气成分主要为酯类、醇类、醛类、烯类和酮类,不同酵母发酵葡萄酒中的香气成分差别微小,而含量差别明显。其中CSM、D254 和F15 酵母发酵的葡萄酒分别检测到56、57、57 种香气成分。三者主要香气含量的差异说明了香气成分的含量与比例在决定葡萄酒香气感官质量上的重要性。     

Volatile aroma and sensory analysis of black raspberry wines fermented by different yeast strains

Robus coreanus Miquel is a small berry fruit used for Korean black raspberry (KBR) wine‐making. Twelve different yeast strains were investigated by laboratory‐scale fermentation to develop a wine with a high flavour quality. Volatile aroma compounds from the wines were analysed using headspace–solid phase microextraction–gas chromatography–mass spectrometry and sensory evaluation was performed to evaluate the flavour characteristics. The volatile aroma compounds that mostly contributed to the flavour of KBR wines were those related to fruity (esters) and floral (terpenes) aromas. Fifteen out of the 67 identified volatile compounds showed higher odour activity values than other compounds in the wines, and these compounds were considered as important contributors to the final aromas of the wine. Additionally, the KBR wine fermented by the M1 yeast strain had the highest sensory preference because of higher fruity and floral aroma characters compared with other wines. In addition to the M1 strain, the other yeast strains that produced favourable sensory characteristics included Enoferm CSM, Uvaferm VRB, Lalvin ICV GRE, Lalvin ICV Opale and LevureSeche Active. Of these strains, the M1 strain produced a particularly excellent black raspberry wine, and thus could be applied for further large‐scale production of black raspberry wines. It is also expected that this work will expedite research on the production of high‐quality black raspberry wines with beneficial physicochemical properties, functionality and good sensory characteristics. Copyright © 2015 The Institute of Brewing & Distilling     

添加葡萄籽单宁对橡木桶陈酿‘赤霞珠’和‘马瑟兰’干红葡萄酒香气的影响

采用气相色谱-质谱联用法和感官分析排序法,研究橡木桶陈酿前添加葡萄籽单宁（200 mg/L）对陈酿12 个月后‘赤霞珠’和‘马瑟兰’干红葡萄酒香气组分和感官特征的影响。结果表明：添加葡萄籽单宁对2 个品种葡萄酒香气的影响各异。葡萄籽单宁添加促进了橡木桶陈酿期间‘赤霞珠’葡萄酒中香草酸、香草醛、香草酸乙酯、糠醛、乙酰呋喃和糠醇等橡木来源香气物质的浸出,而抑制‘马瑟兰’干红葡萄酒中糠醛、乙酰呋喃、糠醇、5-甲基糠醛和5-羟甲基糠醛等橡木来源香气物质的浸出。添加葡萄籽单宁后,‘赤霞珠’葡萄酒的生青味和浆果香降低,烘烤味增强,‘马瑟兰’葡萄酒的生青味和花香略有增强,对陈酿型干红葡萄酒的生产具有重要指导作用。     

Aroma compounds and sensory characteristics of Arneis Terre Alfieri DOC wines: the concentration of polyfunctional thiols and their evolution in relation to different ageing conditions

Arneis is an Italian autochthonous white grape cultivar. This study involved investigating the chemicophysical, aromatic composition and sensory evaluation of Arneis wine in relation to different oenological practices during winemaking and ageing. For the first time, polyfunctional thiols related aromas were identified above their perception threshold in Arneis wine. Moreover, citrus, grapefruit and tropical fruit notes characterized this wine during the first month of ageing, thus suggesting a strong correlation between chemical and sensory results. The concentration of thiols decreased rapidly during the first month of ageing, together with the tropical fruit notes. In particular, the perception of the grapefruit note of the wine decreased in association with the 3-mercaptohexyl acetate content in both the barrel and stainless steel (ST) aged wines. Moreover, the ageing technique clearly affected wine composition and sensory profile; barrel aged wines were characterized both by vanilla and honey notes, and a weaker perception of thiols despite containing a similar concentration to ST aged wines. Within this study, the ability of glutathione to decrease the oxidation of volatile thiols in Arneis wine was confirmed, but under experimental conditions employed, the addition of reduced glutathione did not lead to any statistically significant differences in sensory results.     

Effect of alternative techniques to ageing on lees and use of non-toasted oak chips in alcoholic fermentation on the aromatic composition of red wine

The aim of this work was to evaluate the effect of different enological treatments on the volatile composition of red wine: ageing on lees with and without adding β-glucanase enzymes; the use of a commercial yeast derivative with and without β-glucanase enzymes; and the use of non-toasted chips in fermentation. The results indicated that the presence of chips during the fermentation enhanced the formation of 2-phenylethanol, ethyl esters and fusel alcohol acetates, but affected the levels of some of the lactones and volatile phenols studied negatively. In addition, it was found that wine lees and commercial yeast derivatives can bind some of the volatile compounds studied, mainly ethyl esters and fusel alcohol acetates. After 6 months in bottle, in general, the differences found between the control wine and wines fermented with chips were maintained. However, between the control wine and the wines treated with natural or commercial yeast, the differences disappeared, although not for all the compounds studied. Finally, an important effect of the addition of β-glucanase enzymes was not observed.     

橡木片对霞多丽葡萄酒发酵的影响

该文研究在发酵过程中添加法国中度烘烤橡木制品对霞多丽干白葡萄酒的影响,增加霞多丽干白葡萄酒酿造工艺的选择性.接种酵母菌进行酒精发酵的同时在葡萄汁中添加法国中度烘烤橡木制品,未添加橡木制品发酵的样品为对照样,分别在发酵降糖50％和酒精发酵结束时测定理化指标、有机酸与挥发性化合物的含量.结果表明:添加橡木制品发酵对霞多丽葡萄酒化学物质有一定影响,其总高级醇、总橡木挥发性化合物含量较高.而对照样的葡萄酒中总酸和总酯含量较高,总高级醇含量是添加橡木制品发酵的葡萄酒中总高级醇含量的70％～85％,而酸类物质含量是添加橡木制品发酵葡萄酒的2倍.     

Effect of the Closure Type on the Evolution of the Physical‐Chemical and Sensory Characteristics of a Montepulciano d'Abruzzo Rosé Wine

The present work studied the effect of the kind of closure (a screw cap, a natural cork, and 2 synthetic closures) on the evolution of the oxygen content and on the physical‐chemical and sensory characteristics of a Montepulciano d'Abruzzo rosé wine during the 1st 12 mo of bottle aging. The chemical analyses concerned the parameters more involved in the oxidative reactions (SO₂, acetaldehyde, phenols, wine color), as well as the main fermentative volatile compounds. The kind of closure influenced the oxygen content in wines, free and total SO₂ concentration, and wine color (color intensity and hue). During bottle aging, free and total SO₂ concentration was significantly and negatively correlated with absorbance at 420 nm (A420), whereas the correlations with A520 were weak. Probably, the limited extent of the variations in red color (A520), when varying SO₂ concentration, were due to the low pH of this rosé wine. No effect of the kind of closure on phenols and the main fermentative volatile compounds was observed. The wines bottled with cork closures (N trials), after 12 mo of storage, had higher color intensity and hue, measured by spectrophotometry, and were visually distinguished from the other trials for the more intense pink reflections. On the whole, under the conditions of this work, all the used closures guaranteed a good preservability to the rosè wines during the 1st year of bottle aging, and the changes in composition did not significantly affect wine sensory characteristics. Therefore, these synthetic closures can represent an alternative to the cork closures for a medium to long term bottle aging of these wines.     

The influence of yeast on the aroma of Sauvignon Blanc wine

The main objective of this study was to investigate the effect of different Saccharomyces cerevisiae wine yeast strains on the concentration of aroma-enhancing volatile thiols and fermentation metabolites in Sauvignon Blanc wine. Seven commercial wine yeast strains were selected based on their putative ability to modulate the concentrations of the fruity volatile thiols, 4-mercapto-4-methylpentan-2-one (4MMP), 3-mercapto-hexanol (3MH) and 3-mercapto-hexylacetate (3MHA). Each of these yeasts was used to produce Sauvignon Blanc wines under controlled conditions, in triplicate, in 20-L quantities. The levels of 4MMP, 3MH and 3MHA in these wines were quantified using the p-hydroxymercuribenzoate method. In addition, a total of 24 volatile yeast-derived fermentation aroma compounds were also quantified using headspace solid-phase microextraction coupled with gas chromatography mass spectrometry (HS-SPME–GC–MS). Formal sensory analysis was conducted by 12 trained assessors and, additionally, a panel of 24 experienced wine industry professionals assessed the wines and ranked them in order of preference. The results indicated that the yeast strains varied significantly in terms of their capabilities to (i) produce volatile thiols and fermentation metabolites; and (ii) to modulate the varietal characters of Sauvignon Blanc wine. Yeast strains that produced the highest levels of volatile thiols were responsible for wines with the highest perceived intensity of fruitiness, and these wines were preferred by the tasting panels. While the ‘green’ characters in Sauvignon Blanc wines can be manipulated through vineyard management, the ‘tropical fruity’ characters appear to be largely dependent on the wine yeast strain used during fermentation. Therefore, the choice of yeast strain offers great potential to modulate wine aroma profiles to definable styles and predetermined consumer market specifications.     

橡木片陈酿对赤霞珠干红葡萄酒品质的影响

为了提高橡木片陈酿赤霞珠干红葡萄酒品质,设计橡木片添加量分别为0、4 g/L、6 g/L、8 g/L和10 g/L的5个不同处理组,未加橡木片的为对照组,陈酿期间通过定期测定各组色度、色调值以及花色苷、单宁和总酚含量等理化指标的变化,并结合干红葡萄酒感官品质评定,确定橡木片最佳添加量。结果表明,对赤霞珠干红葡萄酒橡木片陈酿时,橡木片最佳添加量为6 g/L、陈酿时间为45 d。在此种陈酿方式下,葡萄酒的理化指标和感官品质可得到明显改善和提升。     

Astringency,bitterness and color changes in dry red wines before and during oak barrel aging: An updated phenolic perspective review

To understand effects of using oak barrels on the astringency, bitterness and color of dry red wines, phenolic reactions in wines before and after barrel aging are reviewed in this paper, which has been divided into three sections. The first section includes an introduction to chemical reactivities of grape-derived phenolic compounds, a summary of the phenolic reactions that occur in dry red wines before barrel aging, and a discussion of the effects of these reactions on wine astringency, bitterness and color. The second section introduces barrel types that determine the oak barrel constituents in wines (primarily oak aldehydes and ellagitannins) and presents reactions between the oak constituents and grape-derived phenolic compounds that may modulate wine astringency, bitterness and color. The final section illustrates the chemical differences between basic oxidation and over-oxidation in wines, discusses oxygen consumption kinetics in wines during barrel aging by comparing different oxygen consumption kinetics observed previously by others, and speculates on the possible preliminary phenolic reactions that occur in dry red wines during oak barrel aging that soften tannins and stabilize pigments via basic oxidation. Additionally, sulfur dioxide (SO₂) addition during barrel aging and suitability of adopting oak barrels for aging wines are briefly discussed.     

蛇龙珠营养系干红葡萄酒中的挥发性风味物质

确定蛇龙珠不同营养系葡萄酒中挥发性风味物质的差异及对其感官品质的影响。利用顶空固相微萃取和气相色谱-质谱联用技术对8 个蛇龙珠营养系干红葡萄酒中50 种主要挥发性成分进行定性和定量检测,采用香气活性值（odor activity value,OAV）、单因素方差分析和主成分分析对测定数据进行处理分析。结果显示：在蛇龙珠干红葡萄酒中β-大马酮等24 种化合物OAV不小于1,对葡萄酒香气具有贡献。乙酸乙酯等12 种化合物可较好实现对8 个蛇龙珠营养系干红葡萄酒的判别分类,E-01、E-02、E-04、E-05营养系间存在明显差异,而E-06、E-07和E-08之间差异很小。结合感官品评结果发现,γ-壬内酯和里哪醇对提高蛇龙珠干红葡萄酒感官品质具有较大贡献,但含量需控制在一定范围内;而壬醛和4-乙基苯酚含量较高会显著降低葡萄酒感官品质,此外,β-大马酮、乙酸乙酯、癸酸乙酯等含量较高也会对葡萄酒的感官品质带来负面影响。蛇龙珠干红葡萄酒的香气特点不是由某个或某类香气成分产生的,是各种香气成分平衡作用的结果。     

Scientific evidences beyond the application of inactive dry yeast preparations in winemaking

In recent years the use of inactive dry yeast (IDY) preparations such as inactive yeast, yeast autolysates, yeast extracts and yeast hulls or walls have been widely used within the oenological industry to improve either technological processes or the sensory characteristics of wines. Some of these preparations have very specific applications and there are currently many of these products in the market under different brands that promise different ways of improving wine characteristics. Nevertheless, scientific information about the chemistry beyond their use and their action mode is still scarce.The objective of this review is to revise the different applications of specific IDY preparations in winemaking, on the basis of their action mechanisms taking into consideration the scientific information available, underlining the necessity of more scientific work in order to better characterize their chemical composition, their action mechanisms, and the establishment of better criteria for their oenological use.     

The Chardonnay wine olfactory concept revisited: A stable core of volatile compounds, and fuzzy boundaries

An earlier study by the same team showed that Chardonnay wines have common olfactory properties by which wine experts can recognize them. The specific Chardonnay olfactory space was also tentatively linked to the relative concentrations of 29 volatile compounds, regarded as possible aroma-impact compounds. The question now is whether or not those initial results hold independently of the sample under consideration, that is, whether these sensory and chemical spaces are vintage-specific. A series of investigations was conducted on a new set of 46 wines (23 Chardonnay wines and 23 non Chardonnay wines) using the same sensory (wine typicality level) and physico-chemical (Gas Chromatography-mass spectrometry-selected ion monitoring: GC-MS-SIM) approaches as in the earlier study. The sensory space of Chardonnay wines has been identified again in this new study. Compared with white wines of other grape varieties, Chardonnay wines do have distinctive and recognizable olfactory characteristics. LSD tests carried out on the chemical data and a PLS analysis predicting wine typicality level from the chemical data showed that the relative concentrations of 35 volatile compounds affected the wines' typicality scores. Of the 35 compounds, 18 were already among the 29 possible aroma-impact compounds identified by the earlier study. These 18 common volatile compounds seem to be vintage-independent and as such might represent the core of the Chardonnay wine olfactory space. The others seem to be specific to the new wines tested and may contribute to the fuzziness of the boundaries of the Chardonnay wine olfactory space. These results emphasize the complexity of the odor quality of Chardonnay wines, with some volatile compounds remaining stable across vintages, while others are specific to enological practices and to vintages.     

Effect of Short Ageing on Lees on the Mannoprotein Content,Aromatic Profile,and Sensorial Character of White Wines

In Albariño white wines, aging of wines on lees is a technique not used or only used empirically by some producers to obtain a distinctive character in the final wine. This study analyzes the influence of a short aging on lees on the chemical and sensorial parameters of this young white wine. Albariño grape must was inoculated with a locally selected yeast (Saccharomyces cerevisiae 1) and the effect of a short aging on lees was studied during different times (10, 20, 30, 40, and 50 d). Mannoprotein content and the aromatic profile were determined and a sensorial analysis of the wines was conducted. Results showed that aging time was correlated with the concentration of some key aroma compounds and mannoproteins in Albariño wines. The best sensorial character was obtained in wines aged 20 d on lees. Further aging times decreased the sensorial quality of Albariño wine and modified its volatile profile and mannoprotein concentration.     

Effects of nutrient supplementation on fermentation kinetics, H2S evolution, and aroma profile in Verdicchio DOC wine production

Different yeast nutrient additions were studied for the 2008 and 2009 vintages of Verdicchio grape juice fermentation. Addition of yeast derivatives at the beginning of fermentation and/or different amounts of diammonium phosphate at various times within the first half of fermentation were examined, with initial yeast assimilable nitrogen concentrations set at 200 and 250 mg l^?1. Supplementation with glutathione in combination with this nitrogen addition was also evaluated. Fermentation rates were monitored throughout these fermentations carried out under different nutrient conditions. H₂S production during fermentation and synthesis of volatile compounds in the finished wines were quantified; the wines also underwent sensory evaluation. The fermentation kinetics were almost exclusively influenced by the inorganic nitrogen supplementation with diammonium phosphate. H₂S evolution was more affected by assimilable nitrogen than glutathione. Diammonium phosphate significantly reduced H₂S production, with a further reduction in the presence of yeast derivative. This nitrogen supplementation yielded higher concentrations of acetate esters, and in particular of isoamyl acetate (fruity aromas), which positively influences the analytical and aroma profile of wines and results in a general reduction in 2-phenylethanol production (floral aromas). Overall results (two harvesting times and vintages) indicate that the management with diammonium phosphate and yeast derivative supplementation improves the kinetics of fermentation and provides a good tool to reduce H₂S formation and increase the analytical and sensory quality of Verdicchio wine.     

Impact of using Trepat and Monastrell red grape varieties on the volatile and nitrogen composition during the manufacture of rosé Cava sparkling wines

The impact of using Trepat and Monastrell red grape varieties during the manufacture of rosé sparkling Cava wines on the nitrogen and volatile composition compared to a white Cava manufactured with a blend of typical white grape varieties (Xarello: Macabeo: Parellada) has been investigated. The wines were industrially manufactured in a cellar, and the concentrations of outstanding nitrogen compounds and 23 target volatile compounds belonging to different chemical classes were determined in the base wines and in the corresponding Cava wines after 9, 12, 15 and 18 months of aging on lees. After the application of multivariate statistical analysis, the results showed the large effect of the variety employed in the manufacture of Cavas compared to the changes in wine composition due to the aging time. Depending on the composition, Trepat and White Cava wines were more similar than those manufactured with the variety Monastrell. However, the sensory study showed that the two rosé Cava wines had good sensory attributes and even slightly better foam characteristics than the white ones. The sensory study highlighted for the first time the adequacy of using Monastrell red grape variety to manufacture rosé sparkling wines.