Impact of Processing Parameters on the Phenolic Profile of Wines Produced from Hybrid Red Grapes Maréchal Foch,Corot noir,and Marquette

Phenolic extraction in hybrid and interspecific wine grape cultivars is poorly understood, especially in terms of the impact of fermentation and enological conditions on condensed tannins and anthocyanins. Following fractionation via solid‐phase extraction and high‐performance liquid chromatography, phenolic profiles of must and wine from red hybrid grape cultivars Maréchal Foch, Corot noir, and Marquette were examined to assess the impact of enzyme and tannin addition, cold soak, and hot press during vinification. Across cultivars, hot press treatments resulted in the greatest extraction of condensed tannin, anthocyanin, and other monomeric phenolic compounds in musts, and treatments that increased skin contact time or cellular degradation during fermentation produced higher concentrations of tannins, anthocyanins, and flavonols. However, these increases were transient, evincing incomplete carryover into finished wines. Depending on initial must extraction, diglucoside forms of anthocyanins were either selectively extracted or selectively retained throughout fermentation when compared to their monoglucoside counterparts. Typical of hybrid grapes, tannin concentrations across cultivars were low, even under hot press conditions. For condensed tannins and anthocyanins, a cultivar‐specific, stable‐state concentration and phenolic profile emerged regardless of fermentation conditions. Due to the high levels of diglucoside anthocyanins and low levels of condensed tannins, it is expected that the color development and profile in these wines produced from hybrid grape cultivars will be dictated by the monomeric anthocyanins and their potential role in copigmentation processes involving other monomeric phenolic species, as opposed to the formation of polymeric color pigments.     

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。     

Changes in the color components and phenolic content of red wines from Vitis vinifera L. Cv. “Tempranillo” during vinification and aging

Changes in phenolics and color components during vinification and aging of Tempranillo wines were studied. Different phenolics display different diffusion into the must, and with the exception of proanthocyanidins and acetyl-glucoside anthocyanins, with maximum concentration at the end of postmaceration, the rest of the unacylated and coumarated anthocyanins, monomeric flavanols, and hydroxycinnamic acids reached their maximum at the end of alcoholic fermentation. This resulted in a significant increase in both wine color and stable color, mainly due to the formation of copigmentation complexes, although polymeric pigment formation was also important. Malolactic fermentation produced a significant decrease in flavonoid content while nonflavonoid concentrations were maintained, prompting a considerable loss in wine color, despite the dramatic increase in bisulfite-stable color. Wine oak aging did not produce any significant change in the studied parameters, while bottle aging reduced the level of monomeric anthocyanins and flavanols, and hydroxycinnamic acids. However, wine color remained stable due to a significant increase in stable color. Polymerization reactions of anthocyanins prevailed over pigment degradation reactions, and copigmentation was still relevant after 2 years of bottle aging.     

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.     

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。     

A new approach to the analysis of tannin concentration using a microelectronic biosensor

Wine tannins are essential to the astringency and color stabilization of red wine through the formation of tannin conjugates. It is important to determine the concentration of tannins during wine aging and fermentation. The aim of this study was to establish a new method that allows for real-time analysis of tannin content in wine and eliminates inconvenient processes, such as calibrations and/or enzyme reactions. The Folin-Ciocalteau spectrophotometry (FCS) was used a positive control and compared it with new microelectrode biosensor cyclic voltammetry (MBCV) method. The new approach was established that not only allows for real-time tannin detection but is also economical and does not require the use of a specific enzyme. The results are reproducible and provide a precise measurement of tannin content.     

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。     

超声波处理对黑米酒中酚类物质、颜色及抗氧化性的影响

研究了超声处理对黑米酒中酚类物质、颜色及羟基自由基清除能力的影响。结果显示:超声波处理后黑米酒中总酚含量、总黄酮含量、总花青素含量及清除自由基能力均有不同程度下降,而黑米酒亮度(L*)、红色(a*)及黄色(b*)的颜色特性均有一定程度增加;不同超声条件处理后,黑米酒中总花青素含量与其a*有明显相关性,表明总花青素是黑米酒呈现红色的主体物质;超声处理后黑米酒清除羟自由基的能力与黄酮、花青素等的变化呈明显相关性。上述部分指标的变化与自然熟化过程变化基本一致,表明超声在一定程度上可以起到辅助黑米酒熟化的作用。     

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.     

Association Between Modification of Phenolic Profiling and Development of Wine Color during Alcohol Fermentation

To solve the problem of wine color instability in western China, different additives (the maceration enzymes Vinozym G and Ex‐color, yeasts VR5 and Red Star, and commercial tannins) were added during alcoholic fermentation of Syrah (Vitis vinifera L.). The phenolic profile and color characteristics of wine were examined using high performance liquid chromatography mass spectrometry and CIELAB, respectively. The results showed that the combination of the enzyme Ex‐color with the Red Star yeast eased the release of non‐anthocyanins from grape berries into wine, whereas the use of enzyme Vinozym G and VR5 yeast enhanced the concentration of anthocyanins and achieved a higher red hue (a* value) and a lower yellow hue (b* value) in the wine. The addition of commercial tannins greatly promoted the level of gallic acid in the wine and led to a relatively higher concentration of anthocyanins. Partial least‐squares regression analysis was used to find out the major phenolics, which were in close relation with color parameters; principal component analysis was used to evaluate the contribution of different winemaking techniques to wine color. The combination of these 2 analytic methods indicated that Vinozym G and VR5 yeast together with commercial tannins should be an appropriate combination to enhance the stability of wine color during alcohol fermentation, which was related to a significant increase in cyanidin‐3‐O‐(6‐O‐acetyl)‐glucoside, cyanidin‐3‐O‐(6‐O‐coumaryl)‐glucoside, trans‐peonidin‐3‐O‐(6‐O‐coumaryl)‐glucoside, trans‐malvidin‐3‐O‐(6‐O‐coumaryl)‐glucoside, and malvidin‐3‐O‐(6‐O‐acetyl)‐glucoside‐pyruvic acid, all of which played an important role in stabilizing wine color.     

Statistical interpretation of the color parameters of red wines in function of their phenolic composition during aging in bottle

The relationships between the color parameters (colorimetric indexes and CIELAB variables) and the phenolic components (anthocyanins, pyranoanthocyanins, hydroxybenzoic and hydroxycinnamic acids, flavanols and flavonols) of young red wines from Vitis vinifera L. cv. Tempranillo, Graciano and Cabernet Sauvignon (vintage 2000, Navarra, Spain), have been investigated during 26 months of wine aging in bottle (a period embracing their commercial life), through the application of different statistical analysis (principal component, correlation and polynomial regression). The results of the principal component analysis first indicated that for each variety a high degree of interrelation existed between the color parameters and the anthocyanin pigments. Moreover, it was found that for each variety the color parameters were correlated with the anthocyanins during aging in bottle. Finally, by the application of polynomial regression analysis, both anthocyanins (simple glucosides and acetyl-glucosides) and pyranoanthocyanins (anthocyanin-pyruvic acid adducts) were selected as the variables that best described the different color parameters during aging in bottle. However, differences were found between varieties in relation to the type of anthocyanin pigment selected for describing each color parameter, finally indicating the importance of the grape variety factor in the definition of the wine chromatic characteristics.     

Chromatic characteristics and anthocyanin profile of a micro-oxygenated red wine after oak or bottle maturation

Micro-oxygenation (MOX) was applied to a red wine for 5 months following the end of alcoholic fermentation and then both a non-oxygenated control wine and the micro-oxygenated wine were matured in oak barrels or bottles. The concentration of anthocyanin and anthocyanin-derived compounds and the chromatic characteristics of the control and micro-oxygenated wines after the maturation period were studied. Anthocyanin and anthocyanin-derived compounds composition were determined by liquid chromatography-mass spectrometry; and, together with monomeric anthocyanins, compounds including direct anthocyanin-flavanol adducts, ethyl-linked anthocyanin-flavanol compounds, and pyranoanthocyanins were identified. The results showed that the improvements in the chromatic characteristics obtained by applying the MOX technique to Monastrell wines were maintained after an aging period in bottle or barrel. The color intensity of wines increased during maturation in oak barrels, whereas the color of the bottled wines decreased, although MOX wines always showed higher color intensity than the respective control wines. Bottled wines also showed a higher increase in tint and a lower quantity of compounds resistant to SO₂ discoloration than oak matured wines, indicating that the formation of these compounds is favored by the oxidative conditions in oak barrels.     

Evolution of the antioxidant capacity and phenolic contents of persimmon during fermentation

The changes in antioxidant capacity and phenolics of persimmon during alcoholic fermentation, acetification, and short aging were investigated. An increase in the antioxidant activity was observed when persimmon was transformed from puree to vinegar. The total content of phenolics remained stable, in contrast to the concentration of condensed tannin, which significantly (p < 0.05) increased during alcoholic and acetic fermentations, although followed by a decrease after aging. The phenolic compounds were characterized and quantitated. Gallic acid was the main phenolic compound, and its content increased by 14.4% during alcoholic fermentation and reduced by 53.5% during acetic fermentation. Additionally, the flavan-3-ol compounds increased during alcoholic fermentation and acetification. Vanillyl alcohol, (?)-epigallocatechin, and p-coumaric acid were not observed in persimmon puree but detected in persimmon wine and vinegar. These results indicate that alcoholic and acetic fermentation can improve the antioxidant capacity of persimmon fruit.     

特色柿子酒酿造工艺

为加强柿子资源的有效利用,提高柿子的附加值,本文采用抗坏血酸和柠檬酸对柿子浆进行护色处理,并用酒曲或果胶酶处理柿子浆,进行特色柿子酒酿造工艺的研究。结果表明,相比于原柿子浆,在柿子浆中添加酒曲和果胶酶可分别使柿子出汁率提高98.7%和192.3%,同时使柿子浆中可溶性单宁含量分别降低51.0%和13.4%。不同处理组的柿子酒蒸馏液可溶性单宁含量均小于0.2 mg/g。采用明胶对单宁含量较高且较浑浊的发酵底液进行脱涩及澄清处理,添加2.5%的明胶,可使酒曲和果胶酶处理组的发酵底液中可溶性单宁含量降至1 mg/g左右,透光率升至90%左右。勾兑后的柿子酒酒精度30% vol左右,酒体清亮,无涩味,果香浓郁,具有广阔的市场前景和开发推广潜力。     

Effect of winemaking practices on color indexes and selected bioactive phenolics of Aglianico wine

ABSTRACT:  Phenolic compounds are responsible for the sensory properties of wine as well as the properties beneficial to human health. The objective of this study was to establish the effect of the use of SO₂ and pectolitic enzymes in the prefermentative phase, maceration time, and oak aging on color, anthocyanins, tannins, (+)-catechin, (–)-epicatechin, rutin, trans -resveratrol, and quercetin content of Aglianico wine. Color indexes and phenolics were analyzed by HPLC and spectrophotometric methods. The addition of SO₂ and pectolitic enzymes before fermentation caused an increase in color intensity, color stability, total phenolics, anthocyanins, (+)-catechin, (–)-epicatechin rutin, trans -resveratrol, and quercetin content in Aglianico wine. Longer maceration times gave wines richer in total phenolics and with better chromatic characteristics. Storage in oak caused a decrease in anthocyanins, (+)-catechin, (–)-epicatechin, trans -resveratrol, and quercetin content but an increase in total phenolic content, and a stabilizing effect on color also occurred.     

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。     

The Influence of Prefermentative Addition of Gallic Acid on the Phenolic Composition and Chromatic Characteristics of Cabernet Sauvignon Wines

In this study, the prefermentative addition of gallic acid in Cabernet Sauvignon red winemaking was performed. The influence of gallic acid addition on wine phenolic composition, the ratio of copigmentation, and the color parameters were monitored throughout the winemaking process. The results showed that the prefermentative addition of gallic acid enhanced the extraction of total anthocyanins and the copigmentation effect, producing wines with more darkness, redness, yellowness, and saturation. Moreover, the addition of gallic acid contributed to the concentration of total phenolic acids. However, it had a negative effect on the concentrations of flavonols and flavan‐3‐ols in the final wines. Thus, the prefermentative addition of gallic acid at appropriate levels might be a promising enological technology to obtain wines with high color quality and aging potential.     

Influence of Fermentation Process on the Anthocyanin Composition of Wine and Vinegar Elaborated from Strawberry

Anthocyanins are the major polyphenolic compounds in strawberry fruit responsible for its color. Due to their sensitivity, they are affected by food processing techniques such as fermentation that alters both their chemical composition and organoleptic properties. This work aims to evaluate the impact of different fermentation processes on individual anthocyanins compounds in strawberry wine and vinegar by UHPLC‐MS/MS Q Exactive analysis. Nineteen, 18, and 14 anthocyanin compounds were identified in the strawberry initial substrate, strawberry wine, and strawberry vinegar, respectively. Four and 8 anthocyanin compounds were tentatively identified with high accuracy for the 1st time to be present in the beverages obtained by alcoholic fermentation and acetic fermentation of strawberry, respectively. Both, the total and the individual anthocyanin concentrations were decreased by both fermentation processes, affecting the alcoholic fermentation to a lesser extent (19%) than the acetic fermentation (91%). Indeed, several changes in color parameters have been assessed. The color of the wine and the vinegar made from strawberry changed during the fermentation process, varying from red to orange color, this fact is directly correlated with the decrease of anthocyanins 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.     

A Comparison of the Effect of Macerating Enzymes and Pulsed Electric Fields Technology on Phenolic Content and Color of Red Wine

ABSTRACT:  The effect of the addition of 2 enzymatic preparations and the application of a pulsed electric fields treatment (PEF) on the phenolic content and color of Cabernet Sauvignon wine has been compared. The evolution of color intensity (CI), anthocyanic content (AC), and total polyphenol index (TPI) from crushing to 3 mo of aging in bottle was studied. The results demonstrated that both treatments promoted greater extraction of phenolic compounds, compared to the untreated wine. However, PEF technology was more effective. After 3 mo of storage, CI, AC, and TPI were 28%, 26%, and 11%, respectively, higher in PEF-wine than in control wine. By contrast, while both enzymatic preparations increased the CI of the wine around 5%, only one of them increased the AC and TPI by 11% and 3%, respectively, in comparison with the control. After 3 mo of aging in bottle, the phenolic composition was also analyzed by high-performance liquid chromatography (HPLC). The content of nonanthocyanic families was higher in PEF-wine than in the rest of the wines. In wines treated by enzymes, only an increase in phenolic acids and flavonols with respect to the control was detected.
Practical Application: Pulsed electric fields is a novel food processing technology that poses a very promising future to the enological field, due to its capacity to improve the mass transfer phenomenon. The continuous development of this technology allows nowadays the application of treatments at the semi-industrial scale. In this article, it has been demonstrated that the application of a PEF treatment to the grape pomace before maceration/fermentation is more effective, in terms of color intensity and phenolic content, than the addition of macerating enzymes.