Influence of locally-selected yeast on the chemical and sensorial properties of Albariño white wines

The use of selected yeast strains with improved or novel properties may promote wines with special and original quality attributes. In this paper, changes in the chemical composition (aroma compounds and polyphenols) and sensorial properties of Albariño white wines elaborated with the same must and selected yeast (named as 1, 2 and 3) have been studied in comparison with wines subjected to non-inoculated fermentation (control wine). The results indicated that yeast strain can significantly influence the aroma and polyphenol composition of the wines. Wines elaborated with strain 1 had a higher concentration of terpenes and norisoprenoids, which are compounds closely associated with the fruity and fresh character of Albariño white wines. These same wines had a lower concentration of flavan-3-ols, closely associated with the astringency and bitterness of the wine and the lowest browning potential. The formal sensory analysis conducted by 8 trained judges showed that wines elaborated with strain 1 were preferred by the tasting panel. Therefore, the selection of yeast strains could offer the possibility to modulate sensorial attributes related with the aroma and phenol composition in Albariño white wines.     

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.     

Effect of Maceration Time on Free and Bound Volatiles of Red Wines from cv. Karaoğlan (Vitis vinifera L.) Grapes Grown in Arapgir,Turkey

Skin maceration is an essential winemaking technique that affects sensory properties and aroma of red wines. The aim of this study was to investigate aroma profiles of red wines made from cv. Karao?lan, a grape variety grown in Arapgir (Malatya, Turkey) and the effect of maceration time (5, 10, and 15 d) on free and bound aroma compounds and sensory properties. Three maceration times were applied in durations of 5, 10, and 15 d. Free and glycosidically bound aroma compounds were analyzed using gas chromatography‐mass spectrometry (GC‐MS) in Karao?lan wines, and the effect of different maceration times on aroma composition were evaluated. Results indicate that extended maceration time significantly influenced the aroma composition of wines both qualitatively and quantitatively. A total of 59 free and 22 bound aroma compounds were identified in the final wines. The maximum of free aroma content was achieved with 5 d of maceration, while 15 d of maceration gave the highest amount of glycosidically bound aroma compounds. From sensorial point of view, the wine produced with 10 d of maceration had the best panel score compared to wines with 5 and 15 d of maceration. This is the first study referring to the composition of aroma compounds of red wines made from cv. Karao?lan. It was concluded that this cultivar resulted in a good quality wine in terms of bound and free aroma compounds. This information of vinification practices that influence the chemical properties of wine is useful for grape growers and winemakers.     

Effect of terroir on the volatiles of Vitis vinifera cv. Albariño

The effect of terroir on volatiles of Vitis vinifera cv Albariño was studied. Twelve commercial Albariño wines from Galicia, Spain, were analysed. The content of varietals and fermentative volatile compounds was determined by gas chromatography. The numerous significant differences found for most of the aromatic compounds studied show the influence of the terroir. The Albariño wines from northern Galicia showed the highest total concentration of volatiles analysed. The volatile components showing the greatest differences in Albariño wines from different areas were terpenes and higher alcohols. Among the terpenes found, geraniol was markedly abundant in the north, while nerol and linalool were most abundant in the south. Among the alcohols, 2‐phenyl ethanol and benzyl alcohol showed the highest concentrations in the south and in the north, respectively. Cluster analysis and principal component analysis revealed two clearly defined main groups of Albariño wines from different terroirs. Albariño wines from the south were more heterogenic than those of the north. Copyright © 2007 Society of Chemical Industry     

Repercussion of the clarification treatment agents before the alcoholic fermentation on volatile composition of white wines

Albariño must was clarified with two fining agents, as bentonite and silica gel. Alcoholic fermentation was carried out at semi-industrial scale, and the concentration of free monoterpenes, norisoprenoids, C₆-alcohols, higher alcohols, fatty acids, ethyl esters, and acetates was then investigated. The use of bentonite allows loss of several volatile compounds compared to wine control. In a second step, the effect of clarification–stabilization treatments with silica gel on aromatic substances was compared in order to study this influence in white wines elaborated from different aromatic varieties (Albariño and Loureira). The results showed that the use of these fining agent plays a significant role in the wine volatile composition.     

Effects of Different β‐D‐Glycosidases on Bound Aroma Compounds in Muscat Grape Determined by HS‐SPME and GC‐MS

Important “floral” aromas naturally occur in grapes predominantly as flavourless glycoconjugate precursors. Since these aroma compounds can be released by hydrolysis, different glycosidase enzymes can potentially contribute different aromas to wines. In this paper, we first established a procedure for profiling the free and bound volatile compounds in grape using GC‐MS combined with headspace solid‐phase microextraction (HS‐SPME). Comparison of the free and bound aroma compounds revealed that non‐volatile glycosides, known as aroma precursors, occur in high concentrations in musts. Among all compounds identified, 11 were fully quantified according to established standard calibration curves, while others were semi‐quantified. Using three different glycosidase enzymes, a total of 38 bound volatile compounds were identified in Muscat grape, including terpenes, higher alcohols, C‐6 compounds, and phenols, among others. The different enzymes had significant effects on the varietal aroma. Principal component analysis indicated that the characteristic aroma hydrolyzed by the commercial enzyme AR2000 was clearly different from that produced by other enzymes.     

Influence of yeast mannoproteins in the aroma improvement of white wines

Abstract: In the present work, 3 different yeast strains (1, 2, and 3) were used to elaborate white wines using Albariño must. The concentration of polymeric mannose was determined using a method based on the mannoprotein precipitation, hydrolysis and analysis of sylylated mannose derivatives by gas chromatography. Wines elaborated with the strain 1 (W1) presented a higher mannoprotein concentration than the other wines. The analysis of the volatile composition of wines showed significant differences (P < 0.05) among them, being W1 which presented the highest concentration of aroma compounds, mainly terpens and norisoprenoids. The sensorial analysis of wines also showed that W1 had the best quality. The results obtained from this work demonstrate that mannoproteins could be involved in the behavior observed. Some evidences were obtained using a model wine, where 2 major terpens in W1 were preferentially retained by the colloids rich in mannoproteins released by strain 1. Practical Application: White wines elaborated with yeast strains overproducing mannoproteins could have better quality than others. Mannoproteins could contribute to aroma enhancement of Albariño white wines     

Enhancement of volatile aromatic compounds in black raspberry wines via enzymatic treatment

Robus coreanus Miquel is widely used in the production of Korean black raspberry (KBR) wine owing to its health benefits and commercial value. The effects of three different commercially available glycosidase enzymes on the volatile compounds in KBR wines were investigated with large‐scale fermentation to develop a high‐flavour‐quality wine. Volatile aroma compounds from the wines were analysed using headspace‐solid phase micro‐extraction‐gas chromatography–mass spectrometry (HS‐SPME‐GC–MS) and sensory evaluations were performed to evaluate the flavour characteristics. KBR wines treated with commercial enzymes yielded high concentrations of terpenes and esters compared with the control wine because the odourless non‐volatile glycosides in KBR wines were converted to their corresponding free forms by the enzymes. HS‐SPME‐GC–MS‐SIM analysis showed that the primary monoterpene compounds in KBR wines treated by the enzymes were myrtenol, linalool, citronellol and a significant quantity of compounds such as 2‐phenyl ethanol and ethyl benzoate, which contributed to the flavour of KBR wine, as determined by GC‐FID. KBR wines treated with the enzymes exhibited different sensory characteristics from the control wine owing to higher intensity of floral and fruity aromas. KBR wine treated with CYTOLASE PCL5 on a large scale exhibited the highest sensory preference. Copyright © 2017 The Institute of Brewing & Distilling     

Improving colour extraction and stability in red wines: the use of maceration enzymes and enological tannins

Two commercially available maceration enzymes and two enological tannins were tested in Monastrell wines to determine their suitability for improving the chromatic characteristics, colour stability and sensory properties of the resulting wines. The greatest differences for all the wines, when comparing with the control wine, were observed at the beginning of the winemaking process, any differences diminishing in the finished wines. One of the enzyme‐treated wines was used showed hardly any difference from the control wine, whereas the other enzyme‐treated wine showed an improvement in their chromatic and sensory characteristics. The use of two different enological tannins did not provide any improvement in the chromatic and sensory characteristics of the wines, imparting a higher yellow colour and resulting in lower scores in the colour and aroma sensory characteristics, accompanied by a higher astringency, dryness and bitter sensory sensations.     

Inhibition and inactivation evaluation of exogenous glycosidases in wines using p‐nitrophenylglycosides

BACKGROUND: Glycosidases are often used to improve the aroma of wines via hydrolysis of glycosidic precursors. The aim of this work was to develop a method to test activity and stability of these enzymes in wine environments using p‐nitrophenylglycosides, avoiding interference by colored substances. RESULTS: The proposed procedure for determination of glycosidase activity in wines involves quantification of the hydrolysis product p‐nitrophenol by HPLC. The method was applied to compare the inhibition of some commercial glycosidases by red and white wines. It was found that inhibition of a β‐D ‐glucosidase by ethanol, glucose and gluconolactone was smaller than that produced by wine. This enzyme was also inhibited by wine fractions rich in phenolic compounds and glycosides. When glycoside fractions were first hydrolyzed, their inhibition was strongly reduced. The stability of glycosidases in red wines was tested, showing a destabilizing effect of β‐glucosidases that was stronger than in white wine. CONCLUSION: The method developed allows measurement of glycosidase activity on p‐nitrophenylglycosides in the presence of colored wine compounds. Comparison of relative glycosidase activity in wines to that in buffer solution under the same conditions can assist in the selection of appropriate aroma‐enhancing enzymes. Copyright © 2009 Society of Chemical Industry     

Enhancement of Aroma in White Wines Using a β-Glucosidase Preparation From Debaryomyces pseudopolymorphus (A-77)

The liberation of aromas in young wines is presently one of the most interesting subjects in enology. The hydrolysis of the glycosidic compounds (aroma precursors) of grape varieties from Castilla-La Mancha (Spain) has been studied, using an enzymatic preparation from Debaryomyces pseudopolymorphus (A-77) with high β-glucosidase activity. This preparation was added to the wines and its effect was observed at 6 and 12 days of incubation. Enzymatic activity was studied quantifying both the precursors that were not hydrolysed and those that liberated volatile compounds by gas chromatography/mass spectrometry.

The results were compared with a control wine (without enzyme) and also with a wine treated with a commercial fungal enzyme preparation specifically recommended for the liberation of aromas in wines. It was observed that the enzymatic extracts from D. pseudopolymorphus were adequate and that they could compete with the commercial preparations since the volatiles liberated were more controlled and it took less time to get the same results. To complete the study, the results obtained in regards to the liberation of volatiles were corroborated by sensory analysis.     

CO2浸渍毛葡萄酒香气成分的GC/MS分析

为研究CO2浸渍工艺对干红毛葡萄酒香气成分的影响,采用仪器辅助液液萃取方式提取传统工艺和CO2浸渍工艺酿造的干红毛葡萄酒中的香气成分,并进行气相色谱/质谱(GC/MS)联机分析.结果表明:2种葡萄酒中共鉴定出48种香气化合物,主要为醇类、酯类、酸类和酚类物质等,其中传统葡萄酒中鉴定出32种,而CO2浸渍葡萄酒中鉴定出41种.和传统葡萄酒相比,CO2浸渍酒中仅有酸类物质的含量发生轻微下降,其他物质(如醇类、酯类和酚类等)的含量以及香气物质的总含量都表现出不同程度的上升.综合来看,CO2浸渍工艺酿造的干红毛葡萄酒的香气质量比传统工艺酿造的葡萄酒要好.     

沙棘原汁澄清处理对沙棘酒香气成分的影响

为研究沙棘原汁澄清处理对沙棘酒发酵速度和香气成分形成的影响,利用果胶酶对沙棘原汁进行澄清处理。分别对沙棘澄清汁和未处理的沙棘原汁调整到糖度23%、pH3.7,然后接入0.18%的活性干酵母于28.5℃下发酵,陈酿后采用气-质联用仪(GC-MS)对各发酵酒进行香气成分检测。结果表明:以澄清汁为原料发酵的沙棘酒中检测出58种香气化合物;原汁发酵的沙棘酒中检测出52种香气成分,其中有28种非两者共有,产生了非常明显的香气差异。主要香气成分为3-甲基-1-丁醇和辛酸乙酯,用澄清汁发酵的沙棘酒其相对含量分别为31.24%和10.40%,较原汁发酵的沙棘酒分别提高了16.45%和5.32%。因此表明对沙棘汁澄清处理更有利于沙棘酒香气的形成。     

Influence of low temperature prefermentative techniques on chromatic and phenolic characteristics of Syrah and Cabernet Sauvignon wines

Low temperature prefermentative techniques (cold maceration, superficially frozen grapes and dry-ice frozen must) were studied as an enological alternative for obtaining highly colored wines and compared with other more common practices, such as the use of maceration enzymes during the maceration step. The experiments were conducted with two grape varieties (Syrah and Cabernet Sauvignon) during the 2007 season. Significant differences were found between the treatments at the three moments analyzed (at the end of alcoholic and malolactic fermentation, and at the moment of bottling). The cold maceration technique produced the highest concentration of anthocyanins in Cabernet Sauvignon wines. As regards chromatic parameters, the prefermentative low temperature techniques led to wines with a better color than the control wine although similar to the color obtained when a commercial maceration enzyme was used. Taking into account the results in both Cabernet Sauvignon and Syrah wines, freezing the must with dry-ice and the use of maceration enzyme were the most interesting techniques.     

Enhancement of Aroma in White Wines Using a β-Glucosidase Preparation From Debaryomyces pseudopolymorphus (A-77)

The liberation of aromas in young wines is presently one of the most interesting subjects in enology. The hydrolysis of the glycosidic compounds (aroma precursors) of grape varieties from Castilla-La Mancha (Spain) has been studied, using an enzymatic preparation from Debaryomyces pseudopolymorphus (A-77) with high β-glucosidase activity. This preparation was added to the wines and its effect was observed at 6 and 12 days of incubation. Enzymatic activity was studied quantifying both the precursors that were not hydrolysed and those that liberated volatile compounds by gas chromatography/mass spectrometry.

The results were compared with a control wine (without enzyme) and also with a wine treated with a commercial fungal enzyme preparation specifically recommended for the liberation of aromas in wines. It was observed that the enzymatic extracts from D. pseudopolymorphus were adequate and that they could compete with the commercial preparations since the volatiles liberated were more controlled and it took less time to get the same results. To complete the study, the results obtained in regards to the liberation of volatiles were corroborated by sensory analysis.     

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.     

EFFECTS OF DIFFERENT MACERATION TIMES AND PECTOLYTIC ENZYME ADDITION ON THE ANTHOCYANIN COMPOSITION OF VITIS VINIFERA CV. KALECIK KARASI WINES

Kalecik karasi is an important red grape cultivar for winemaking in Turkey. The effect of three different maceration times (3, 6 and 12 days) and addition of pectolytic enzyme (2 and 4 g/hL) on the anthocyanin and chemical composition of Kalecik karasi wines were studied. High performance liquid chromatography-mass spectrometry coupled with diode array detection was used for analysis. Fourteen anthocyanin compounds were detected in wines. Major anthocyanins in all wines are malvidin-3-glucoside and its acylated esters. The results showed that increasing maceration time, especially with addition of enzymes, gives significant increases in anthocyanin contents. Moreover, the wines treated with enzymes had higher values in total phenolics, tannins, and color intensity than the control wines.

PRACTICAL APPLICATIONS

Anthocyanins are the most important polyphenols in red grapes and red wines with potential health benefits. Therefore, the first analysis of the anthocyanins contents of wine obtained from important turkish cv. Kalecik karasi using liquid-chromatography-mass spectrometry and the influence of different maceration times and addition of pectolytic enzyme on these important phenolic compounds are of interest for scientific literature, the wine industry as well as for the wine consumer.     

Polyphenolic Composition and Antioxidant Activity of Galician Monovarietal Wines from Native and Experimental Non-Native White Grape Varieties

Galicia region (Northwestern Spain) wine production is mainly focused to high-quality white wines. The polyphenolic composition and the antioxidant activity have been determined to characterize the wines obtained from white grape varieties (Albariño, Branco Lexitimo, Caiño blanco, Godello, Loureiro, Torrontes, and Treixadura) grown in Galician protected production areas, and the wines elaborated with non-native varieties experimentally grown in Galicia (Chardonnay, Gewürztraminer, Pinot blanc, Pinot gris, Riesling, and Sauvignon blanc). Since Albariños are the varietal wines with the highest production and commercialization extension, we have studied their polyphenolic composition as a function of the production subarea. Three vintage years (2010, 2011, and 2012) have been considered to account for climate variability. Liquid chromatography with diode array and mass spectrometry detection was used to obtain the phenolic profiles. Wines from native grapes could be fully discriminated by their phenolic composition, with only Albariño being partially confused with other varietal wines. Albariño wines produced in O Rosal and Ribera do Ulla could be clearly differentiated, whereas Condado do Tea and Val do Salnés wines were partially confused. The polyphenolic profile was enough to differentiate the wines obtained from non-native grapes. The total polyphenols content and the antioxidant activity of white wines elaborated in Galicia were comparable, although significant differences were found among varieties.