Sesquiterpenes in grapes and wines: Occurrence,biosynthesis, functionality,and influence of winemaking processes

Grapes are an important global horticultural product, and are mainly used for winemaking. Typically, grapes and wines are rich in various phytochemicals, including phenolics, terpenes, pyrazines, and benzenoids, with different compounds responsible for different nutritional and sensory properties. Among these compounds, sesquiterpenes, a subcategory of the terpenes, are attracting increasing interest as they affect aroma and have potential health benefits. The characteristics of sesquiterpenes in grapes and wines in terms of classification, biosynthesis pathway, and active functions have not been extensively reviewed. This paper summarizes 97 different sesquiterpenes reported in grapes and wines and reviews their biosynthesis pathways and relevant bio‐regulation mechanisms. This review further discusses the functionalities of these sesquiterpenes including their aroma contribution to grapes and wines and potential health benefits, as well as how winemaking processes affect sesquiterpene concentrations.     

Influence of winemaking technologies on phenolic composition of Italian red wines

The aim of this study was to assess the influence of different winemaking technologies on the chemical characteristics and, in particular, on the phenolic fraction of Aglianico, Montepulciano, Nero di Troia and Sangiovese wines produced in Apulia, Southern Italy. Four different winemaking technologies were compared: control (traditional, 5 days of maceration at 25 °C with three daily punching-down), prolonged maceration (10 days), addition of ellagic tannins and cryomaceration (24 h at 5 °C using dry ice), without any other oenological treatment. Results showed that the different technologies slightly influenced the phenolic fraction of Aglianico, which is known to be naturally rich of phenols. On the contrary, the prolonged maceration led to an increase of total phenols (TP) in Nero di Troia (2,592 mg/kg vs. 2,115 mg/kg of control) and a decrease in Sangiovese (869 mg/kg vs. 1,013 mg/kg); the addition of tannins led to an increase of TP in Montepulciano (1,358 mg/kg vs. 1,216 mg/kg) and to a decrease in Sangiovese (916 mg/kg vs. 1,013 mg/kg); and cryomaceration led to a decrease of anthocyanins in all cultivars (about 15%). Phenols extraction from grapes was found to be mostly dependent on the grape variety rather than on the applied winemaking technology.     

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     

Influence of grape variety and their phenolic composition on vasorelaxing activity of young red wines

Red wine has been reported to exert beneficial effects in preventing cardiovascular diseases probably due to their polyphenols constituents. The vasorelaxant capacity and phenolic composition of four monovarietal young red wines Merlot, Tempranillo, Garnacha and Cabernet-Sauvignon obtained from grapes from 2004 vintage, cultivated under the same climatic and agricultural conditions, wine-making technology and storage conditions, were determined using vascular reactivity assay in rat aortic and high-performance liquid chromatography, respectively. Primary cultures of vascular smooth muscle cells from Wistar rats were also used to evaluate their survival prevention activity as well. Every studied wine present vasorelaxation effect, but the higher value corresponds to the analyzed Merlot wine, especially rich in phenolic compounds, mainly catechins and oligomeric proanthocyanidins and anthocyanin glycosides. This study further demonstrated previous investigations about the phenolic composition of wines relation with their vasorelaxation activity.     

Evaluation of different Saccharomyces cerevisiae strains for red winemaking. Influence on the anthocyanin,pyranoanthocyanin and non-anthocyanin phenolic content and colour characteristics of wines

The possible industrial use of three previously-selected Saccharomyces cerevisiae strains (1EV, 2EV and 7EV) has been studied in musts derived from Tempranillo and Cabernet Sauvignon. The anthocyanin, pyranoanthocyanin and non-anthocyanin phenolic content, and colour characteristics of the resulting wines have been compared to those of a commercial strain. Anthocyanins were the compounds most influenced by the yeast strain. Independently of the grape variety, wines derived from 2EV presented significantly higher anthocyanin concentrations than those derived from 1EV and 7EV, which presented similar contents. With the exception of hydroxycinnamic acids and derivatives, no particular influence of the yeast strain was observed on the remaining non-anthocyanin phenolic compounds (i.e, hydroxybenzoic acids and flavanols). Pyranoanthocyanins and metabolites resulting from the alcoholic fermentation such as tyrosol and tryptophol, seemed to be more influenced by the must composition and pH, and thus, by the grape variety, than by the yeast strain.     

超声波提取条件对酿酒葡萄皮渣花色苷的影响

为了比较不同超声提取条件对酿酒葡萄皮中花色苷组分的影响,同时也为葡萄皮渣的开发利用提供依据。采用不同超声波功率和超声时间提取酿酒葡萄皮渣中的花色苷组分,并利用高效液相色谱-质谱联用技术（HPLC-MS）对提取物中的花色苷成分进行检测。结果表明,超声波辅助提取葡萄皮渣花色苷,不仅可以显著提高花色苷的提取量,还可增加花色苷的提取类型。此外,采用不同的超声功率或超声时间提取葡萄皮花色苷,对花色苷的提取量和组成均具有影响。60W超声功率处理20min提取的葡萄皮花色苷的含量最高,高达（60.95±5.26）mg/L。      

Influence of the heterogeneity of grape phenolic maturity on wine composition and quality

Nowadays, consumers demand red wines with deep colour, soft tannins and fruit scents, but these wines can only be obtained from grapes with complete phenolic maturity. Diverse methods have been proposed for measuring phenolic maturity. However, all these methods only provide the average value and do not consider any possible heterogeneity. Throughout ripening, grapes were separated according to their density, which revealed the existence of a large heterogeneity. Grapes at harvest were also separated by density in three groups. The higher the density of the grapes the higher ethanol content, pH, colour intensity, total phenolic index and anthocyanin and proanthocyanidin concentrations, and the lower the titratable acidity and bitterness of the wines. When the grapes were denser the wines were also better balanced in flavour and mouthfeel sensation. These results suggest that grape heterogeneity may influence the final wine composition and quality and therefore it should be considered at harvest.     

Influence of winemaking techniques on the resveratrol content, total phenolic content and antioxidant potential of red wines

In this paper, the influence of winemaking techniques and cultivars on the resveratrol content, total phenolic content and antioxidant potential of red wines was studied. Wines were made from the cultivars Merlot, Cabernet Sauvignon, Pinot Noir and Prokupac. Applied winemaking technologies included thermovinification and separation of must from pomace. The analysis of trans- and cis-resveratrol in wines was performed by HPLC, while the total phenolic content and antioxidant potential was determined by spectrophotometric methods. The total resveratrol content in analysed samples ranged from 0.35 to 4.85 mg/l; Merlot wines had the highest average resveratrol content, while the lowest was found for native cultivar Prokupac. Although the resveratrol content depended on grape variety, correlation between the winemaking technology applied and the resveratrol level in wines was not observed. The total phenolic content (TPC) varied from 544.4 to 1410.4 mg/l expressed as gallic acid equivalents, and the antioxidant potential, assayed by DPPH in terms of SC₅₀ (mean scavenging concentration), ranged from 0.58 to 2.91 μl/ml. Obtained results showed that thermovinificated wine samples had higher amount of phenolic compounds. Significant negative correlation was observed (p < 0.05) between the total phenolic content and SC₅₀, but there was no significant correlation (p > 0.05) between the resveratrol content and SC₅₀ or TPC. This study could contribute to the establishment of optimal conditions for producing red wines which contain more beneficial phenolic compounds.     

Quantitative determination of the odorants of young red wines from different grape varieties

Fifty‐two young monovarietal red wines made with Grenache (17 samples), Tempranillo (11 samples), Cabernet Sauvignon (12 samples) and Merlot (12 samples) grapes have been analysed by HRGC–MS to obtain quantitative data on 47 odorants previously identified as potential aroma contributors by olfactometric techniques. Thirty‐three odorants were present in the wines at concentrations higher than their corresponding odour thresholds. These include ethyl octanoate, β‐damascenone, ethyl hexanoate, isovaleric acid and isoamyl acetate as the most important, which together with isoamyl and β‐phenylethyl alcohols, fatty acids, 2,3‐butanedione and ethyl butyrate are always found at concentrations higher than their odour thresholds. In some cases the ethyl esters of isobutyric and isovaleric acids, β‐ionone, methionol, isobutyric acid, ethyl cinnamate, ethyl dihydrocinnamate, γ‐nonalactone, eugenol, c‐3‐hexanol, geraniol, guaiacol, 3‐isobutyl‐2‐methoxypyrazine, 4‐ethylguaiacol, acetoin and t‐whiskylactone were at a concentration high enough to be odour‐active. There were 30 compounds that were found to differ significantly between varieties. These include 3‐isobutyl‐2‐methoxypyrazine, isoamyl acetate, isovaleric acid, ethyl isobutyrate, ethyl isovalerate, fusel alcohols, c‐3‐hexenol, methionol, eugenol, guaiacol and γ‐nonalactone. © 2000 Society of Chemical Industry     

Influence of different aging systems and oak woods on aged wine color and anthocyanin composition

The evolution of a red wine, Cigales appellation in origin, was studied during its storage in three different aging systems (barrels, chips, and staves) made of different kinds of oak wood (American, French, and Hungarian). The results obtained were analyzed in order to determine the content of anthocyanins in wine according to the aging system used. The studied variables were monoglucosides of delphidin, cyanindin, peonidin, petunidin and malvidin (as acetic and p-coumaric esters), as well as vitisin A, malvidin-3-O-caffeylglucoside, and color variables. The relationship between the anthocyanins and color variables stressed the importance of these compounds during the formation of pigments characteristic of aged wine, and highlighted how they are affected by the aging system chosen.Analysis of the results allowed us to define the evolution of the wine accordingly to the aging system and the botanical species of wood used. Wine treated with chips evolved more quickly than wines treated with the other two systems, because there was a higher loss of anthocyanins and an increase in brownish tonalities. On the other hand, wine treated with Hungarian oak wood suffered a slightly higher loss of anthocyanins than those aged with French and American oak wood.     

红提葡萄与酿酒葡萄复合果酒发酵工艺优化

该研究以新疆红提葡萄为主要原料,加入酿酒葡萄（宝石解百纳、赤霞珠）后制备红提葡萄与酿酒葡萄复合果酒,探讨最佳酿酒葡萄种类,并通过单因素及响应面试验探寻红提葡萄与酿酒葡萄复合果酒的最佳发酵工艺参数。结果表明,最佳酿酒葡萄为赤霞珠,红提葡萄与赤霞珠的质量比为4∶1;最佳发酵工艺条件为发酵温度20 ℃,初始pH值4.4,初始糖浓度28 °Bx。在此优化条件下,发酵所得红提葡萄与酿酒葡萄复合果酒的感官评分为95分,酒精度为8%vol,残糖量为13 °Bx,其色泽透亮,口感酸甜,果香浓郁,典型性明显,其理化指标及微生物指标均符合国家相关标准。     

Oenological potential of wines produced from disease-resistant grape cultivars

Within the EU, changes in policy and public sentiment have made it more urgent to consider the adoption of sustainable agricultural practices. Consequently, one of the EU’s goals is to reduce pesticide use by 50 per cent by 2030, including in viticulture. One of the proposed approaches is to expand the use of disease resistant hybrid grape-cultivars (DRHGC), such as ‘PIWI’ grapes (German, Pilzwiderstandsfähige Rebsorten), and to introduce new DRHGCs. However, the characteristics of DRHGCs are different from those of Vitis vinifera, which makes it necessary to take measures and make changes in winemaking technology to maintain high wine quality. This paper examines the chemistry of wines made from DRHGC and discusses their impact on aroma and flavor profiles. It also reviews the main winemaking practices suggested to produce high-quality wines from DRHGCs. The chemistry of DRHGCs is different to wine produced from V. vinifera, which can lead to both challenges during winemaking and unusual flavor profiles. Although newer DRHGCs have been bred to avoid unexpected flavors, many DRHGCs are still rich in proteins and polysaccharides. This can make tannin extraction difficult and produce wines with little astringency. In addition to this, new or alternative winemaking techniques such as thermovinification and the use of alternative yeast strains (non-Saccharomyces) can be used to produce wines from DRHGCs that are acceptable to consumers.     

Characterisation and evolution of grape polyphenol profiles of Vitis vinifera L. cv. Tannat during ripening and vinification

Background and Aims: Changes in different polyphenol families during grape ripening and vinification were determined in Tannat grapes. This was done to establish a polyphenol profile for Tannat grapes during ripening and for young wines. Methods and Results: We demonstrated, by high‐performance liquid chromatography with diode array detection and mass spectrometry (HPLC‐DAD‐MS) analysis, that the content of flavan‐3‐ols in Tannat seeds was higher than that reported for a large number of other grape varieties analysed. Forty per cent of the total flavan‐3‐ols in seeds were galloylated compounds, whereas the flavan‐3‐ol profile in skins was characterised by the absence of galloylated forms. Prodelphinidins in skins ranged between 30 and 35% with very low values for epigallocatechin. Epicatechin gallate was not detected in Tannat wine and galloylated forms represented a low percentage of total flavan‐3‐ols. Tannat grapes had very high concentrations of anthocyanins in skins with levels increasing during ripening. Eleven phenolic acids were identified in Tannat grape skins and wines, but only gallic and protocatechuic acids were found in the seeds. Conclusions: Tannat wines were shown to have one of the highest levels of phenolic compounds reported for vinifera grape varieties. The profiles for different polyphenol families present in Tannat grapes (skins and seeds) and wines were determined. Significance of the Study: The results presented will help to better understand the phenolic winemaking potential of this variety and its functional properties within food chemistry.     

Resveratrol,human health and winemaking perspectives

Resveratrol, (3, 5, 4′-trihydroxystilbene) is a non-flavonoid polyphenol stilbene synthesized by plants when damaged by infectious diseases or ionizing radiation. Although present in more than seventy plant species, grapes and wine are the major dietary contributors of resveratrol, responsible for 98% of the daily intake. In 1992, Renaud and De Lorgeril first linked wine polyphenols, including resveratrol, to the potential health benefits ascribed to regular and moderate wine consumption (the so called “French Paradox”). Since then, resveratrol has received increasing scientific interest, leading to research on its biological actions, and to a large number of published papers, which have been collected and discussed in this review. The relatively low amounts of resveratrol measured in wine following moderate consumption, however, may be insufficient to mitigate biological damage, such as that due to oxidative stress. On this basis, the authors also highlight the importance of viticulture and the winemaking process to enhance resveratrol concentrations in wine in order to bolster potential health benefits.     

不同类型葡萄酒中花色素苷的比较

利用高效液相色谱检测干红葡萄酒、桃红葡萄酒、玫瑰香葡萄酒3种类型的葡萄酒中的花色苷.结果表明,这3种葡萄酒中的主要花色苷种类相同.二甲花翠素3-O-葡萄糖苷是这3种葡萄酒中主要的呈色物质,分别占花色苷总成分的51.50％、62.94％、50.62％.干红葡萄酒中每一种花色苷的含量都高于其他2种花色苷的含量,这也是干红葡萄酒的色泽比其他2种酒颜色深的主要原因.