Effects of pre-fermentation enzyme maceration on extraction and colour stability in Pinot Noir wine

Effects of pre-fermentation enzyme maceration on anthocyanins, phenolics, colour and colour parameters were investigated in Pinot Noir ( Vitis vinifera L.) wines made from musts that were macerated for 12 hours at 20°C with a commercial enzyme preparation, Rohapect VR-C (Rohm, Darmstadt, Germany), with and without additions of SO₂. Anthocyanins and phenolics were determined by spectrophotometric and HPLC methods. Standard triplicate microvinifications were conducted in glass vessels. Extraction of anthocyanins was not increased by enzyme treatment. However, wines produced by enzyme maceration had increased visible colour intensity, colour density and polymeric pigment formation. By the end of fermentation, enzyme-treated wines had more polymeric pigment, and less monomeric anthocyanins than non-enzyme-treated wines. The wines were bottled, stored at 12°C and sampled at three, six, eight and 18 months after bottling. Over 18 months, differences between the treatments were maintained. The promotion of the formation of polymeric pigments in enzyme-treated wines continued after the wines were bottled, and the greater content of polymeric pigment led to greater colour density in the enzyme-treated wines. The promotion of polymeric pigment formation in wines by macerating enzyme treatment of the must may be due to the breakdown of protective polysaccharide-protein colloids by hemicellulase and protease activities in the enzyme preparation.     

The influence of wine additives on colour and colour quality of young red wine

Summary Zweigelt 1987, a typical Austrian wine treated with wine additives such as sulphur dioxide,l-ascorbic acid and sorbic acid was stored for 77 days. All characteristic wine components were analysed during the storage period. Only changes in colour could be detected. The changes in the amount of anthocyanins and anthocyanidin chlorides were analysed. The results show that Zweigelt 1987 mixed with wine additives such asl-ascorbic acid or sorbic acid resulted in a larger loss in colour than untreated wine. The changes could be measured photometrically but they were invisible to the naked eye. Appropriate use of wine additives did not appear to deterioriate the ruby colour of young red wine during the period tested.

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Der Einfluß von Wein-Zusatzstoffen auf Farbe und Farbqualität von jungem Rotwein

Zusammenfassung Österreichischer Wein Zweigelt 1987, welcher für die Versuchsreihe unter authentischen Bedingungen hergestellt worden war, wurde mit Weinbehandlungsmitteln wie Schwefeldioxid, Sorbinsäure undl-Ascorbinsäure versetzt. Die Wechselwirkungen der Farbe des Rotweines mit den zugesetzten Chemikalien wurden während einer Lagerzeit von 77 Tagen studiert. Die Anthocyane und Anthocyanidinchloridmengen wurden bestimmt. Die Ergebnisse zeigen, daß Zweigelt 1987, der mitl-Ascorbinsäure bzw. Sorbinsäure versetzt worden war, etwas größere Farbverluste zeigte als unbehandelter Wein. Abschließend wurde festgestellt, daß die Farbveränderungen zwar photometrisch meßbar sind, aber mit freiem Auge nicht erkannt werden. Eine Verwendung dieser Weinbehandlungsmittel in richtiger Dosierung führt zu keiner Verschlechterung der Farbqualität bei jungem Rotwein über den untersuchten Zeitraum.

     

Influence of the elimination and addition of seeds on the colour,phenolic composition and astringency of red wine

Several winemaking techniques have been developed to eliminate seeds to prevent the release of high amounts of very astringent proanthocyanidins, especially when the grapes are unripe. However, there is no scientific information on the effects of this practice. The aim of this paper is to study how the elimination and addition of seeds influence the colour, phenolic composition and astringency of red wine. The elimination of around 80% of the seeds led to a significant decrease of colour intensity and anthocyanin concentration. The addition of seeds originated wines with a greater concentration of total anthocyanin, but did not significantly affect the wine colour. These wines also presented significantly higher levels of proanthocyanidins, a greater proportion of epicatechin-3-gallate, a lower mean degree of polymerization, and, in particular, a drastic increase in astringency. Wines obtained with the elimination of seeds, on the other hand, had exactly the opposite characteristics.     

近红外光谱技术快速检测黄酒的前发酵过程中总酸含量

黄酒是我国最古老的独有酒种,其生产原料来源广,生产工序复杂等因素对黄酒的质量有很大的影响。目前黄酒生产过程中还存在着利用生产经验来判断某段工序是否可以结束的情况,为了探索快速检测黄酒生产过程中各段工序的各项指标的含量的方法,取代人工判别前发酵终点来更准确的控制黄酒的质量,利用近红外光谱仪对黄酒生产过程中前发酵工段所得样品进行扫描,对其光谱进行预处理和波段选择,并结合偏最小二乘法 (PLS)建立各工段快速无损检测方法。最终得到了较高的决定系数R为0.9348,RMSECV值为0.118的模型。结果表明,黄酒前发酵过程选取的总酸含量所建立的模型能很好的用来进行快速检测。运用这些模型对验证集样品进行预测并统计分析,可知预测值与真实值之间无显著差异。本研究为黄酒生产过程的控制提供了方法基础。     

Copigmentation between malvidin-3-glucoside and some wine constituents and its importance to colour expression in red wine

Thermodynamic parameters for intermolecular copigmentation interactions involving malvidin-3-glucoside were determined by UV/visible spectroscopy at wine pH (pH 3.6). These included association constants, enthalpy and entropy changes, which were measured for chlorogenic acid, caffeic acid, quercetin, quercetin-3-glucoside, (−)-epicatechin, (+)-catechin, procyanidin dimer and seed tannin. Quercetin produced the strongest copigment (K_CP = 2900 ± 1300), whilst the addition of glucose at position 3 (quercetin-3-glucoside) reduced its effect by almost 10-fold. Malvidin-3-glucoside self-association (K_D = 3300 ± 300 mol⁻¹ l) was thermodynamically favoured over intermolecular interaction with any of the copigments tested. No colour enhancement due to self-association was observed for malvidin-3-glucoside-derived pigments that cannot enter hydration reactions. In addition, malvidin-3-(6-O-p-coumaryl)glucoside did not show colour enhancement suggesting that the p-coumaryl group prevents self-association. The malvidin-3-glucoside circular dichroism (CD) spectrum was not affected by indicated changes in malvidin-3-glucoside concentration. These observations demonstrate that self-association of malvidin-3-glucoside is more important than copigmentation in young red wine.     

Prediction of red wine colour and phenolic parameters from the analysis of its grape extract

Herein, the phenolic composition and colour attributes of red grapes extracts (obtained with a fast methodology) were correlated with those of their corresponding wines to predict the final quality properties of wines. The phenolic parameters were evaluated as total phenolic compounds (TPC), total anthocyanins (TA) and total condensed tannins (TCT), whereas the chromatic parameters were evaluated as colour intensity (CI), tonality (To), and the percentages of yellow, red and blue tones. All of them were determined by usual UV–Vis spectrophotometric methods. To get robust models, grapes of five red varieties were collected at three different ripening stages throughout the 2009 vintage. Good correlations between the results from grapes and wines were obtained, showing high regression coefficients and low prediction errors for TPC (R² = 0.929, RMSE = 5.99%), TA (R² = 0.953, RMSE = 7.23%) and CI (R² = 0.954, RMSE = 7.58), concluding that these wine phenolic properties can be predicted reliably from the extracts obtained with an optimised fast extraction method from grapes on the ripening controls along the maturity process.     

红葡萄酒减少内皮素-1的合成 --红葡萄酒在预防冠心病上的特殊益处

对红葡萄酒高消费地区所作的统计表明,这些地区的冠心病发病率降低,红葡萄酒可预防冠心病的发生已得到普遍认同.尽管适度饮用任何酒精类饮品都有助于减少冠心病的发病率,但以往的研究并没有明确证明红葡萄酒具有更特殊作用.现在我们证实了红葡萄酒可强烈地抑制内皮素-1的合成,内皮素-1是一种血管活性肽,是冠状动脉硬化形成过程中的关键物质.此发现表明,红葡萄酒中的一些特殊成分有助于预防冠心病的发生.     

发酵型红曲保健酒的研制

红曲固体培养结合蚕蛾、黑蚂蚁、山茱萸、枸杞等中药材料，采用压榨提取、发酵相结合的工艺酿制出保健酒，产品色泽红颜，酒味醇厚，具有一定的保健功能。     

Enological tannins affect acetaldehyde evolution,colour stability and tannin reactivity during forced oxidation of red wine

The addition of enological tannins is a practice admitted and widely used to improve wine phenolic compositions. Although wine ageing is an oxidative process involving phenolic compounds and acetaldehyde production and consumption, the effect of enological tannins on the acetaldehyde and chromatic and phenolic changes of a red wine during oxidation is still not known. In this study, three enological tannins preparations containing gallotannins GT, ellagitannins ET and condensed tannins CT were added to a young commercial Lambrusco red wine in order to obtain wines with three different phenolic compositions. Samples were then treated with hydrogen peroxide to trigger oxidation. All added tannins have determined a production of acetaldehyde greater than control. Acetaldehyde was then consumed in 30 days. The samples treated with CT and ET showed, after oxidation, an increase in colour intensity, determined as the sum of 420, 520 and 620 nm absorbances. A simultaneously increase in polymeric pigments was detected. No significant variation of the Saliva Precipitation Index (SPI), an index useful to give an indirect measure of wine astringency, was observed after 30 days of treatment of CT and ET samples. Results highlight that the addition of CT and ET can help to stabilise colour without affecting wine reactivity towards salivary proteins. A significant role of acetaldehyde has been even detected. These are the first data showing the effect of different enological tannins on the production and consumption of acetaldehyde formation during an oxidation process.     

红葡萄酒中的多糖

1多糖的来源 1.1来自于葡萄本身的多糖 葡萄酒中的多糖部分主要包括在机械操作过程中,富含纤维素和果胶的葡萄皮所释放的多糖分子.     

半干红杨梅果酒复合酵母菌发酵工艺

含酸量较高的杨梅原汁比较适合酿造半干红型的杨梅果酒。葡萄酒酿酒活性干酵母可用作主发酵菌种,适宜接种量为0.3%,但酒色偏淡,原有天然芳香物质损失较大。以0.3%葡萄酒酿酒酵母为主发酵菌种,配合0.1%生香酵母或酿酒高活性酵母可在一定程度上改善酒质,其中生香酵母有提高酒香、酒色和缩短发酵时间的作用;而酿酒高活性酵母对缩短发酵时间和提高酒色效果明显。杨梅果酒不宜采用较高的陈酿温度,最好低于40℃。     

Enhancement of indirect sulphation of limestone by steam addition

The effect of water (H?O(g)) on in situ SO? capture using limestone injection under (FBC) conditions was studied using a thermobalance and tube furnace. The indirect sulphation reaction was found to be greatly enhanced in the presence of H?O(g). Stoichiometric conversion of samples occurred when sulphated with a synthetic flue gas containing 15% H?O(g) in under 10 h, which is equivalent to a 45% increase in conversion as compared to sulphation without H?O(g). Using gas pycnometry and nitrogen adsorption methods, it was shown that limestone samples sulphated in the presence of H?O(g) undergo increased particle densification without any significant changes to pore area or volume. The microstructural changes and observed increase in conversion were attributed to enhanced solid-state diffusion in CaO/CaSO? in the presence of H?O(g). Given steam has been shown to have such a strong influence on sulphation, whereas it had been previously regarded as inert, may prompt a revisiting of the classically accepted sulphation models and phenomena. These findings also suggest that steam injection may be used to enhance sulfur capture performance in fluidized beds firing low-moisture fuels such as petroleum coke.     

分光光度法测葡萄酒的色度

本文探讨了用分光光度计葡萄酒色度的方法及注意的问题。红葡萄酒的色度可用其在420nm，520nm,620nm下的吸光值之和表示，但是直接测其吸光值和稀释液，其结果不同，应根据吸光值的范围来决定使用方法；另外，葡萄酒色度还受pH影响，随着pH增大，色度值也增大。     

菊花红葡萄酒的研制

用酿制的红葡萄酒与菊花浸提液、蔗糖及柠檬酸进行调配试验,制得一种既具有菊花药用和香味,又具有传统葡萄酒特色,营养及口感俱佳的新型葡萄酒。其配方为红葡萄酒70%,菊花液15%,蔗糖10%,柠檬酸0.15%。     

Effect of the prefermentative addition of copigments on the polyphenolic composition of Tempranillo wines after malolactic fermentation

The influence of the prefermentative addition of copigments and different winemaking technologies on the polyphenolic composition of Tempranillo red wines after malolactic fermentation was studied. Six experiments dealing with the prefermentative addition of caffeic acid, rutin, (+) catechin, white grape skin tannin, white grape seed tannin and control wines were realised. Three different winemaking technologies (traditional vinification, prefermentative cold maceration at 6–8 °C and cold soak at 0–2 °C with dry ice) were studied. Prefermentative addition of copigments increases anthocyanin copigmentation reactions and produces wines with a greater colour, a higher anthocyanin concentration, a superior contribution of anthocyanins to the colour of the wine, a superior percentage of tannins polymerised with polysaccharides and less astringency. Cold prefermentative maceration increases the extraction of polyphenols, the anthocyanin copigmentation reactions and the polymerisation reactions between tannins and polysaccharides. The effectiveness of the combination of copigments and prefermentative maceration treatments was demonstrated by the increase of the concentration of the polyphenolic compounds.     

Effect of different pre-fermentation treatments on polyphenols,color, and volatile compounds of three wine varieties

Wines produced by three different grape varieties were treated with seven pre-fermentation techniques to analyze their variation in polyphenolic compounds, color parameters, and aromatic components. For polyphenolic compounds and color parameters, a better result was obtained after the grape pulp treatment, with the maximum impact observed after joint treatment with thermovinification and pectolytic enzymes, followed by thermovinification and cold soak, while pectolytic enzymes treatment alone was ineffective, resulting in almost no effect. On the contrary, the application of thermovinification and cold soak treatments before crushing the whole juice led to a dramatic decline in most indexes. For aromatic components, the joint treatment of thermovinification and pectolytic enzymes on grape pulp significantly affected its amount and type, in addition to giving the wine a mellow aroma.     

Effects of fining with different bentonite labels and doses on colloidal stability and colour of a Valpolicella red wine

This study addressed four different labels of activated sodium bentonite during the fining of a young Valpolicella red wine. Preliminary tests determined the bentonite dose (0.15, 0.30 or 0.50 g L^?1) that would achieve colloidal stability, and this dose was further applied during laboratory‐scale trials. The bentonites were characterised by physico‐chemical parameters, and the effects of the label and dose on the wine colloidal stability, proteins, colour indices and phenolic compounds were measured. The results demonstrated that 0.50 g L^?1 for every bentonite label provided colloidal stabilisation without harshly affecting the colour. Unlike to what happens in white wines the least charged bentonite labels were effective at stabilising the red wine colloidal state by partially reducing its protein content. Simultaneously, the most negatively charged clay samples determined the largest depletions on the total polyphenols, anthocyanins, tannins and polymeric pigments. The differentiated action of clays with different surface charge density among white and red wines may be explained by the interaction mediated by positively charged anthocyanins towards either protein or tannin depletion. Although pioneering, these results may move towards the definition of a safe, allergen‐free, and effective adjuvant for colloidal stabilisation targeted to wine type.