Effect of the Prefermentative Addition of Five Enological Tannins on Anthocyanins and Color in Red Wines

Abstract: The effects of prefermentation addition of 5 exogenous tannins with different‐origin anthocyanins and color characteristics were investigated in “Cabernet Sauvignon wines” at the end of alcoholic fermentation and the end of malolactic fermentation, and after 6 mo and 9 mo of bottle aging, respectively. The results showed that the application of GSKT2 could significantly retard the degradation of most anthocyanins in the process of alcoholic fermentation and the decrease of some pyranoanthocyanins during the subsequent 3 stages, thus causing more yellowness of wine in comparison with the control. Three other condensed tannins, GSKT1, QUET, and GSET, had a positive impact only on several anthocyanin components. Four condensed tannins all contributed to more redness, suggesting that the action mechanism might be to protect wine against oxidation or contribute to form copigmented anthocyanidins, or polymeric pigments. The application of FOLT (hydrolysable tannin) did not produce any influence on wine redness even after 9 mo of bottle aging. This work provides some reasons for the reasonable application of tannin additives. Practical Application: The prefermentative application of condensed tannins overall could protect some pigment components from degradation and enhance wine redness. Tannin additives with different origins have different effectiveness. The tannin additive obtained from grape skins, like GSKT2, could produce significant promotion on both redness and yellowness in wine. The prefermentation addition of hydroxylase tannin like FOLT seems not to have a significant effect on wine color.     

不同皮渣浸渍发酵时间对葡萄酒中缩合单宁构成及感官品质的影响

为明确不同皮渣浸渍时间对葡萄酒中缩合单宁的影响,以赤霞珠和西拉为材料,进行不同浸渍发酵时间处理,对葡萄皮和葡萄籽以及葡萄酒中缩合单宁的含量、组成、缩合单宁以及相关口感指标等进行了分析。结果表明,不同葡萄品种中缩合单宁的初始含量、聚合度及没食子酰化率都有显著差异（P<0.05）。葡萄皮中缩合单宁的平均聚合度显著高于葡萄籽（P<0.05）,而葡萄皮缩合单宁的没食子酰化率则显著低于葡萄籽缩合单宁（P<0.05）。葡萄皮和葡萄籽中缩合单宁组成的最大差异是葡萄籽缩合单宁中不含有（?）-表棓儿茶素亚单元,而且末端单元主要是由（+）-儿茶素、（?）-表儿茶素和（?）-表儿茶素没食子酸酯组成。皮渣浸渍时间对葡萄酒中缩合单宁的组成及含量都有明显影响。随着浸渍时间的延长,葡萄酒中缩合单宁的总含量呈上升趋势,而平均聚合度则呈下降趋势。不同品种的葡萄酒之间缩合单宁含量也存在显著差异（P<0.05）,这与不同葡萄品种中酚类物质的可浸提率有关。葡萄酒中葡萄皮缩合单宁的占比一直显著高于籽粒缩合单宁的占比（P<0.05）,说明葡萄皮中缩合单宁比葡萄籽缩合单宁更容易浸提到葡萄酒中。相对于苦味和酸味,不同浸渍时间处理对葡萄酒的涩味影响更为显著（P<0.05）,综合考虑酒体的丰满度和口感的平衡,皮渣浸渍时间选择14 d左右更好一些。     

Microwave Maceration of Pinot Noir Grape Must: Sanitation and Extraction Effects and Wine Phenolics Outcomes

Pinot noir grapes have a unique phenolic profile which can impinge on the extraction and stabilisation of compounds such as anthocyanins and tannins which contribute to the colour and mouthfeel of red wine. This study examined the concentration of phenolic compounds in Pinot noir grape must and wine following application of a novel microwave maceration treatment for red grape must. Microwave maceration was shown to be highly effective for extraction of phenolics from grape solids into grape juice. When juices were fermented to wine, ultraviolet–visible spectrophotometry showed microwave maceration was associated with significantly higher concentrations of total phenolics, anthocyanin, tannin and pigmented tannin in wine at 18 months bottle age, compared with control wine. Mean tannin concentration in microwave treatment wine was 0.60 gm/L at 18 months, compared with 0.14 gm/L in control wine. The microwave treatment was also associated with a substantial and rapid decrease in the grape-associated yeast population, compared with control maceration, and a shorter lag phase at the outset of alcoholic fermentation. Based on this study, microwave maceration warrants further investigation as a potential industrial-scale application in red winemaking.     

Characterization of Uva Longanesi Red Wine by Selected Parameters Related to Astringency

This research represents a first attempt to chemically characterize wines produced from the autochthonous grape variety, Uva Longanesi, based upon the phenolic compounds responsible for its high astringency as confirmed by preliminary sensory analysis. In addition, a wine produced from Sangiovese, the most popular grape variety in the Emilia-Romagna region, was analyzed for comparative purposes. Results showed that Uva Longanesi wine had a higher pH, alcohol concentration, and total dry extract than the Sangiovese wine. With regards to phenolic constituents, the Uva Longanesi wine had higher color parameters and greater concentrations of total phenolics, including monomeric anthocyanins, small polymeric pigments, and tannins. The phenolic composition of Uva Longanesi wine was found to be responsible for the high reactivity of the wine during fining trials.     

不同单宁提升赤霞珠干红葡萄酒品质的比较分析

本研究以新疆石河子产区所种植的赤霞珠葡萄为实验原料,通过在酒精发酵前分别以两种不同浓度（200 mg/L、400 mg/L）添加4种不同种类的单宁（橡木单宁、缩合单宁、葡萄单宁、鞣花单宁）,探究4种不同种类的单宁在不同添加量下对新疆产区红葡萄酒色泽及口感的影响。结果表明：当所有单宁的添加量在200 mg/L时,葡萄酒的色泽都有所提升,其中添加缩合单宁200 mg/L时,效果最为明显,色度值为21.52,该处理下葡萄酒的色度高出对照组27.25%,且随着陈酿进行到6个月时,添加缩合单宁200 mg/L的葡萄酒色度依然最高,色度值为24.38,且色泽稳定性较好,酒体呈现深宝石红色,香气较浓郁,带有甘草香。实验表明单宁的添加可以改善葡萄酒陈酿后的色泽稳定性,同时使得香气更加浓郁。该实验为新疆石河子产区的实际生产提供理论依据。     

酿酒酵母F15和CC17共接种发酵对赤霞珠葡萄酒品质及感官特性的影响

为解决使用单一商业酵母菌株发酵引起的葡萄酒“同质化”问题,本研究以河北昌黎产赤霞珠葡萄为原料,以商业酿酒酵母（Saccharomyces cerevisiae）F15和本土优良酿酒酵母CC17为发酵剂进行单菌株和双菌株共接种（F15:CC17=1:1）发酵,同时监测酒精发酵过程中比重、温度、残糖、乙醇、总酸、pH、花青素、单宁、总酚、色度和色调的变化。发酵结束（192 h）后,分别对酒的香气成分和感官特性进行了测评。结果表明:与F15单菌株发酵相比,双菌株共接种发酵能够提高赤霞珠葡萄酒中花青素、单宁和总酚含量,增加酒的色度并使色调更趋向于红色;与CC17单发酵相比,共发酵组残糖、总酸含量较低;共发酵调谐主要香气成分,并增加饱和脂肪酸乙酯的含量。此外,感官评价结果表明共发酵葡萄酒色、香、味均优于F15单独发酵。因此,在酒精发酵过程中采用商业酵母与本土菌株共发酵是改善葡萄酒品质和感官特性有效方法。     

Phenolic Content and Antioxidant Activity of Primitivo Wine: Comparison among Winemaking Technologies

ABSTRACT: The aim of this study was to assess the influence of 9 winemaking technologies (traditional, delestage, saignée, delayed punching‐down, addition of grape seed tannins, addition of ellagic‐skin‐seed tannins, heating of must‐wine, cryo‐maceration, and prolonged maceration) on the phenolic content and antioxidant activity of Primitivo musts and wines. Three methods for the determination of the antioxidant activity were compared: DPPH, β‐carotene bleaching assay, and ABTS. Oenological parameters and composition of the phenolic fraction of 1‐y‐aged wines was also determined. The addition of tannins allowed the increase of the phenolic content of musts and wines in a greater amount than the other technologies. The results concerning the antioxidant activity depended on the method applied. Concerning musts, the DPPH assay did not highlight great differences among technologies, whereas the addition of tannins allowed the obtainment of the highest antioxidant activity according to β‐carotene and ABTS assays. The wine aging determined an increase of the antioxidant activity, independently on the method applied. Wine obtained through traditional technology, saignée, and addition of tannins showed the highest antioxidant activities according to DPPH and β‐carotene. The highest correlation coefficients (0.961 and 0.932) were calculated between phenolic content and ABTS values of musts whereas the lowest values (0.413 and 0.517) were calculated between phenolic content and ABTS values of wines. Wines produced through traditional technology were the richest in anthocyanins. The addition of tannins allowed to obtain high content in monomeric anthocyanins, flavonoids, flavans reactive to vanillin, and coumaroylated malvidin and a low content in acetylated malvidin. Practical Applications: It is well known that a moderate consumption (equivalent to 2 glasses per day) of red wine is actually recommended since it appears associated with a decreased incidence of cardiovascular diseases. The mechanisms involved in this protective effect are not completely understood although they appear related to the presence of phenolic compounds. To increase the intake of these compounds without increase of the wine consumption, it is necessary to improve their extraction during maceration. This study could represent a helpful tool for wineries aimed to know the way to increase the antioxidant content of their wines, thus changing them in functional beverages and prolonging their shelf life.     

原料冷冻处理对‘黑比诺’葡萄酒品质的影响

葡萄酒品质很大程度上取决于葡萄原料的质量。为探究酿酒葡萄果实冷冻前处理对葡萄酒品质指标,尤其酚类物质含量的影响,以红色酿酒葡萄品种‘黑比诺’为试验材料,对原料进行常温处理和﹣24℃冷冻处理,在酒精发酵结束后检测葡萄酒的常规理化指标和酚类物质含量。结果表明,原料冷冻处理对‘黑比诺’葡萄果肉中的糖和酸等溶出物影响很小,对源自果皮的成分有显著影响,可提高‘黑比诺’葡萄酒中的干浸出物、单宁、总花色苷、总酚、单体酚和简单花色苷含量,从而显著提升葡萄酒质量。因此,原料冷冻处理可以作为提高葡萄酒品质的前处理措施,推荐用于小规模精品葡萄酒的生产。     

Application of high‐power ultrasounds during red wine vinification

Wine colour is one of the main organoleptic characteristics influencing its quality. It is of special interest in red vinifications due to the economic resources that wineries have to invest for the extraction of the phenolic compounds responsible for wine colour, compounds that are mainly located inside the skin cell vacuoles, where the volatile compounds are also found. The transfer of phenolic compounds from grapes to must during vinification is closely related to the type of grapes and the winemaking technique. During traditional winemaking, grapes are crushed and skin macerated for several days, with pumps overs to facilitate the colour extraction. To increase this extraction, some chemical (maceration enzymes) or physical technologies (thermovinification, cryomaceration, flash‐expansion) can be applied. In this work, a new methodology has been tested. This methodology consists in the application of high‐power ultrasounds to crushed grapes to increase the extraction of phenolic compounds. Crushed grapes were treated with this non‐thermal technology and vinified, with 3, 6 and 8 days of skin maceration time, and the results were compared with a control vinification, where crushed grapes were not subjected to any treatment and were skin macerated during 8 days. The wine chromatic characteristics (determined spectrophotometrically) and the individual phenolic compounds (anthocyanins and tannins, determined by HPLC) were followed during the maceration period, at the end of alcoholic fermentation and after two months in bottle. Also, the wine volatile compounds were determined by GC‐MS. The wines made with ultrasound‐treated grapes showed differences with the control wine, especially regarding total phenol content and tannin content. The wines elaborated with sonicated grapes and with only three days of skin maceration time presented similar concentration of anthocyanins and twice the concentration of tannins than control wines elaborated with 8 days of skin maceration.     

Comparison of fining red wines with purified grape pomace versus commercial fining agents: effect on wine chromatic characteristics and phenolic content

The large quantity of grape pomace (seeds, skin, and peduncle) produced during the winemaking process can be a problem and the search for procedures which could permit their valorisation is considered an important issue. This study investigates the use of purified grape pomace as a fining agent for reducing the level of some wine phenolic compounds, especially tannins. For this, purified grape pomace was applied to three young red wines of different phenolic composition and the results were compared with the effect of some common commercial fining agents. The results demonstrated that grape pomace can be used to decrease the wine tannin content with similar results to those obtained with casein, while also reducing anthocyanin content although to a similar extent to when bentonite is used. The effect of purified Monastrell grapes pomace is similar in the three different studied wines although it affected the most to wines with high monomeric anthocyanin content.     

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.     

Quantification of condensed tannins by precipitation with methyl cellulose: development and validation of an optimised tool for grape and wine analysis

A precipitation assay is presented that enables tannin measurement in matrices of red wine, 50% ethanol grape extract and aqueous tannin solutions. By exploiting the polysaccharide polymer methyl cellulose to precipitate tannins, the absorbance of phenolics at 280 nm before and after tannin precipitation (subtractive approach) can be obtained, thus enabling selective measurement of tannin only. This methyl cellulose precipitable (MCP) tannin assay allows complete precipitation of tannin from red wine and from grape homogenate extracts. The subtractive assay is both simple and robust, selective for condensed tannins and does not suffer interference from other 280 nm-absorbing phenolics such as anthocyanins or catechins. Matrix effects have only minimal impact on the assay performance and validation parameters indicate a robust performance. There was good correlation between tannin measured by reverse-phase HPLC and the MCP tannin assay for 121 Australian red wines ( r = 0.74) and also 54 grape extracts ( r = 0.79). We envisage that the technical simplicity of this tannin assay will enable widespread research and field applications. In addition, an alternative format that requires re-solubilisation of the tannin-polymer pellet in acetonitrile is reported, which is particularly suitable for measurement of smaller tannin concentrations. Notwithstanding that option, technical requirements of the re-solubilisation step lead us to suggest that the subtractive format would be simple for adoption by wine industry practitioners.     

Determination of phenolic compounds in wines: Influence of bottle storage of young red wines on their evolution

Various analytical methods based on the HPLC-DAD technique were used to determine 38 phenolic compounds in red wines. While anthocyanins and hydroxycinnamic acids were determined by direct injection of wine samples, hydroxybenzoic acids, catechins, procyanidins and flavonols required an analytical pretreatment involving liquid–liquid partitioning with ethyl ether followed by solid-phase extraction on C₁₈ mini-columns. The proposed analytical methods were used to establish the phenol composition of Mencía and Brancellao, two varietal young red wines, and its influence on colour stability during storage in bottles for one year. At the end of malolactic fermentation, Mencía wine was found to contain much greater amounts of anthocyan pigments than was Brancellao wine. This resulted in a higher colour density but a weaker hue in Mencía wine than in Brancellao wine. Phenolic compounds evolved similarly in both wines during storage; changes in such compounds involved a decrease in the levels of monomeric anthocyanins, phenolic acids, epicatechin and flavonols, and an increase in those of procyanidins. The absence of a relationship between the changes in colour density and monomeric anthocyanins in both wines suggests that copigmentation and polymerization with other phenolic compounds (viz. phenolic acids, catechins and/or flavonols) prevail over degradation of the pigments.     

适宜‘法国野’葡萄的葡萄酒生产类型探究

为挖掘云南地方酿酒葡萄品种‘法国野’的酿酒潜力,筛选适合该品种的葡萄酒生产类型和基本工艺。采用4种工艺酿制2个类型葡萄酒:浸渍发酵法(maceration-fermentation,MF)酿制干红葡萄酒、冷浸渍+放血法(cold pre-fermentation maceration&saignée,CMS)酿制桃红葡萄酒、冷浸渍+放血+浸渍发酵法(cold pre-fermentation maceration,saignée and maceration-fermentation,CMS-MF)酿制干红葡萄酒,直接压榨法(direct press,DP)酿制桃红葡萄酒,其中2款干红葡萄酒均进行苹果酸-乳酸发酵(malolactic fermentation,MLF)。陈酿3个月后,对4款葡萄酒进行理化指标分析和感官评价。结果表明:与DP和MF相比,CMS和CMS-MF可分别显著提高桃红和干红葡萄酒的单宁、花色苷、总浸出物含量及色度;且CMS和DP桃红葡萄酒的香气、口感和总评得分均显著高于MF和CMS-MF干红葡萄酒,但同类型葡萄酒间的感官质量并无显著差异(P<0.05)。相关性分析表明,感官评价总评得分与酒精度和可滴定酸含量呈显著正相关,与花色苷、单宁和总浸出物含量呈显著或极显著负相关,这证明了MF和MLF工艺均不利于改善‘法国野’葡萄酒的感官质量。此外,与CMS相比,DP可显著提高葡萄汁的还原糖含量和最终葡萄酒的酒精度,并显著降低对单宁的浸提,且保持相当的感官质量。因此,酿酒葡萄‘法国野’更适合于酿造桃红葡萄酒,可将DP作为首选工艺,因其在确保葡萄酒感官质量的同时,又可减少工序、节约成本。     

Phenolic profile of blackberry wine produced using Korean winemaking techniques in earthenware jars

This research evaluated the winemaking potential of ‘Natchez’ and ‘Triple Crown’ blackberries grown in Oklahoma and examined the phenolic composition of blackberry wines made using modified Korean traditional winemaking techniques. The winemaking variables were fermentation temperature (21.6 vs 26.6°C), and fermentation type (yeast inoculation vs wild fermentation). High‐performance liquid chromatography was used to examine the phenolic compounds in blackberry juice and wine. The phenolic compounds consisted of anthocyanins (kuromanin, keracyanidin, delphinidin) and phenolic acids (gallic acid, catechin, caffeic acid, epicatechin, p‐coumaric acid). The ‘Natchez’ berries had higher concentrations of anthocyanins (kuromanin) while ‘Triple Crown’ berries had higher levels of phenolic acids (p‐coumaric acid). For many compounds, a higher fermentation temperature generally corresponded to higher concentrations of the phenolic compound in the wine after three months aging, but this was not universally observed. Accordingly, fermentation temperature may best be matched with individual cultivars via experimentation in order to maximise extraction and retention of phenolic compounds in the finished wines. Overall, the Korean traditional winemaking technique may be a good technique to add value to wines made from blackberries suited for production in a mid‐continental climate such as the central USA. © 2018 The Institute of Brewing & Distilling     

闪蒸对昌黎产区‘马瑟兰’葡萄酒单体酚类物质的影响

以欧亚种酿酒葡萄‘马瑟兰’为试材,研究闪蒸处理对葡萄酒发酵及陈酿过程中单体酚类物质和CIELab色泽参数的影响。结果表明,与传统浸渍发酵（对照组）相比,闪蒸有利于提高发酵过程中多数单体花色苷的质量浓度,但不利于保持陈酿过程中各单体花色苷质量浓度。闪蒸增加了葡萄酒发酵及陈酿过程中槲皮素-3-O-葡萄糖苷、儿茶素、反式白藜芦醇及白藜芦醇葡萄糖苷等非花色苷单体酚类物质的质量浓度,但降低了槲皮素、杨梅酮、酚酸类单体酚、顺式白藜芦醇及白皮杉醇等酚类物质的质量浓度。闪蒸处理可降低葡萄酒亮度L*、黄蓝度b*值和色调角hab,显著增加红绿度a*、色度Cab*值,使葡萄酒颜色更红、更深、更耐陈酿,两组葡萄酒间颜色差异明显。结论：闪蒸有利于增加‘马瑟兰’葡萄酒单体酚总质量浓度及葡萄酒颜色的稳定性。     

Analysis of grape and wine tannins: Methods, applications and challenges

Tannins are polyphenolic secondary metabolites, which can be found in many higher plants and are identified by their ability to complex with and precipitate proteins. This key property is believed to be responsible for the mouth‐feel and astringency caused by wine tannins. The analysis of tannins is of interest to practitioners in a diverse range of fields, including chemistry, pharmacology, food science, animal nutrition, ecology and plant physiology. There is a desire within the Australian wine industry to exploit objective tannin measures to complement human sensory assessment for style and quality specifications. This review, therefore, concentrates on grape‐derived condensed tannins, also known as proanthocyanidins, and wine tannins formed from grape tannins. We summarise recent advances with the development of analytical methods for the quantification of tannins, review techniques for the structural characterisation of tannin molecules and emphasise the need to refine these techniques.     

中国东亚种红葡萄酒的颜色特征及酚类组成研究

为探究东亚种红葡萄酒的颜色特征以及酚类物质轮廓,采用分光光度法、酶标仪和高效液相色谱-串联质谱（HPLC-MS/MS）技术分别对3款东亚种、3款欧亚种及2款杂交种（山葡萄×欧亚种）红葡萄酒的颜色和酚类物质组成进行分析,并对其花色苷衍生物进行鉴定。结果表明,与欧亚种红葡萄酒相比,东亚种红葡萄酒的辅色花色苷含量较高（55.63%～55.66%）,而聚合花色苷含量较低（19.63%～27.01%）,并且花色苷含量较为丰富（399.30～829.95 mg/L）,以花色素-3,5-O-双葡萄糖苷为主（＞97.50%）,酰化花色苷较低（＜21.78%）。花色苷衍生物检测结果表明,东亚种红葡萄酒中的花色苷与（表）儿茶素聚合产物和吡喃花色苷的含量极低（痕量水平）。东亚种红葡萄酒在非花色苷酚组成上的突出特点为单体和二聚体黄烷醇的含量极低,因此其对酒体颜色的潜在影响可能较小。     

冷浸渍及单宁处理提升赤霞珠葡萄酒的品质

为研究冷浸渍及单宁处理对赤霞珠葡萄酒颜色稳定性的影响,以和硕产区赤霞珠葡萄酒为对象,通过发酵前赤霞珠葡萄冷浸渍(8℃下,4 d、8 d、12 d)及发酵过程中添加不同浓度的VR单宁(TANIN VR COLOR,0.10、0.20、0.30 g/L)处理,对赤霞珠葡萄酒的基础理化指标、酚类物质以及CIELab颜色参数进行分析。研究发现,冷浸渍处理(4 d、8 d、12 d)与对照组相比总酸含量分别提升了17.63%、15.70%、26.96%,经过不同浓度(0.10、0.20、0.30 g/L)VR单宁处理的葡萄酒总酸含量分别增加了1.33%、16.74%、13.04%;随着冷浸渍时间的延长,葡萄酒中的单宁和总酚的含量有所增加,而花色苷含量在冷浸渍8 d时达到了最大值111.04 mg/L,添加0.20 g/L VR单宁的酒样单宁、总酚及总花色苷含量分别高于对照组28.40%、26.78%、25.42%;冷浸渍8 d的葡萄酒a^*值和Cab值最高,分别为38.85和42.29,而添加了0.20 g/L VR单宁的葡萄酒b^*值和Hab值与对照组相比分别降低了1.61%、1.84%。综合比较表明,冷浸渍8 d和添加0.20 g/L VR单宁的工艺处理可以有效地提升赤霞珠干红葡萄酒的颜色稳定性。