Accumulation Pattern of Flavonoids in Cabernet Sauvignon Grapes Grown in a Low-Latitude and High-Altitude Region

including (+)-catechin (C), (-)-epicatechin (EC) and (-)-epicatechin-3-O-gallate (ECG). With regard to the effect of training systems, M-VSP contributed to a significantly higher content of total flavan-3-ols, while the percentage of ECG was lower for M-VSP.As for the three flavan-3-ol units (terminal subunits, extension subunits and monomers), the 2012 vintage was more likely to accumulate extension subunits and monomers, and the effect of training system on these three flavan-3-ols units varied between the different vintages. Meanwhile, the proportion of ECG in terminal subunits and of C in extension subunits was higher in 2012, whereas the training system of F-TT had a higher percentage of ECG in extension subunits in both vintages. In addition, the effect of vintage on the composition of flavan-3-ols in harvested grape seeds was more obvious than that of the training system. INTRODUCTIONFlavan-3-ols are responsible for the organoleptic characteristics and biochemical properties of wine. Through the formation of complexes with salivary proteins, flavan-3-ols provide red wine with astringency and mouthfeel characteristics (Casassa & Harbertson, 2014). During wine ageing, flavan-3-ols can also take part in condensation reactions with anthocyanins to stabilise wine colour (Alcalde-Eon et al., 2006;Fulcrand et al., 2006). It is well known that moderate consumption of wine enhances its health benefits, and one of the most important contributors is flavan-3-ols. They possess a number of health-enhancing characteristics, like antioxidants and free radical scavengers, anti-carcinogenics, cardiopreventive and antimicrobial activities, and so on (Renaud & De Lorgeril, 1992;Aron & Kennedy, 2008).Among the phenolic compounds, flavan-3-ols are the most common group of flavonoids. The flavan-3-ols observed in grape seeds are mainly represented by (+)-catechin (C), (-)-epicatechin (EC) and (-)-epicatechin-3-O-gallate (ECG). Proanthocyanidins, as the polymers of flavan-3-ols, are composed of terminal and extension subunits analogous to the flavan-3-ols C, EC and ECG. Subunits are linked via interflavan bonds between C-4 and C-8, and less commonly between C-4 and C-6 (Haslam, 1998). The content and presence of flavan-3-ols in grape seeds depend mainly on variety, soil, climate and viticulture factors, among others. Furthermore, due to a great amount of extraction of flavan-3-ols from grape seeds during the red winemaking process (Sun et al., 1999), their eventual concentration and ability to act as astringents in red wine are affected correspondingly (Ough & Nagaoka, 1984;Morrison & Noble, 1990;González-Neves et al., 2002;Kemp et al., 2011). The extent of bitterness and astringency of wine depends largely on the composition of flavan-3-ols and the degree of polymerisation of proanthocyanidins. It has been reported that a higher proportion of ECG supplies wine with a coarse perception, while epigallocatechin (EGC) flavan-3-ol monomer, which is only found in skins, smooths the taste (Vidal et al., 2003). In addition, the extent...

Section: Principal Component Analysis (Pca)supporting

confidence: 94%

Effect of Training Systems on Accumulation of Flavan-3-ols in Cabernet Sauvignon Grape Seeds at the North Foot of Mt. Tianshan

Liu

Yan

et al. 2018

“…A higher altitude generally corresponds to more intense sunlight, lower temperature, greater temperature difference between day and night, and more extreme environmental conditions (Mateus et al, 2001), all of which are important factors affecting the production of anthocyanins. Furthermore, the effects of altitude on the different monomeric anthocyanins in CS grapes were also different in high-altitude areas (Xing et al, 2015).…”

Section: Content Of Wine Anthocyanin Composition Five Monomeric Anthomentioning

confidence: 95%

Phenolic Characteristics and Antioxidant Activity of Merlot and Cabernet Sauvignon Wines Increase with Vineyard Altitude in a High-altitude Region

Jin

Liu

2017

Altitude, as an important factor in the expression of terroir, may affect wine quality. We evaluated the effect of altitude and its related climatic conditions on the phenolic characteristics and antioxidant activity of red wines made from grapes originating from high-altitude areas. The content of total phenolic compounds, total flavonoids and total anthocyanins increased with altitude in Merlot (ME) and Cabernet Sauvignon (CS) wines. Cabernet Sauvignon wines showed richer tannins with increasing altitude. Merlot and CS wines from higher altitude vineyards, showed a greater antioxidant capacity. Salicylic acid, syringic acid, caffeic acid, (+)-catechin, (−)-epicatechin, and the sum of individual phenolic compounds in the wines increased with altitude based on the results of HPLC. The scores of the sensory evaluation of ME wines increased with higher altitude. The highest score was determined for CS wine originating from 2 608 m. A clear grouping of wines according to grape cultivar and vineyard altitude was observed by principal component analysis. Regression analysis showed that altitude, followed by sunshine hours, made the greatest contribution to differences in the phenolic characteristics and antioxidant activity of red wines at different sites in a high-altitude region. INTRODUCTIONEnvironmental factors such as light and field management practices have a combined effect on grapevine physiology and wine quality (Spayd et al., 2002;Feng et al., 2017). The French term "terroir" is used to define the geographical and environmental origin of grapes grown and harvested during a certain vintage (Deloire et al., 2008). This term includes all regional parameters, such as soil type, climate and orography (Douglas et al., 2001). Terroir is an important factor affecting grape and wine composition (Roullier-Gall et al., 2014).Altitude is usually considered an indirect control on the environmental conditions affecting plant metabolism (Kumar et al., 2006). Therefore, altitude may have a strong effect on climatic conditions that affect grape development and wine quality (Mateus et al., 2002). In particular, altitude gradient may reflect the integrated variation in temperature, humidity and solar radiation in a mountainous region with high vertical zonality (Zhang et al., 2005).Phenolic compounds contribute to a wine's organoleptic characteristics, such as mouthfeel and colour, and are associated with anti-cancer and cardiovascular protection and antioxidant activity (Burns et al., 2000;Skerget et al., 2004). The phenolic compound concentrations of grapes are affected by time of harvest and grape ripeness levels, thereby affecting the flavour and quality of the resulting wine. Phenolic compound concentrations are also affected by genotypes, viticultural practices and environmental conditions (Downey et al., 2006). Variation in phenolic characteristics of wine grapes has often been observed at different altitudes and also has been characterised by regional differences (Mateus et al., 2001(Mateus et al., , 2002Liang et al....

“…The amount of phenolic compounds in grapes is influenced by the grape variety, along with viticultural and environmental factors (which are usually described by the French term "terroir"), which include soil type, geographical location and weather conditions (Douglas et al, 2001;Brescia et al, 2002;Xing et al, 2015). Temperature plays a direct and important role in the formation of phenolic compounds; temperatures higher than 30°C are not conducive to anthocyanin synthesis (Spayd et al, 2002;Tarara et al, 2008).…”

Section: Introductionmentioning

confidence: 99%

“…Flavan-3-ols are mainly responsible for the astringency, bitterness and structure of wines (Monagas et al, 2005), and they also play an important role in the stabilization of the red colour in wines (Sun et al, 2007). Stilbenes (mainly resveratrol) exhibit significant antioxidant properties in the prevention of arteriosclerosis and coronary heart disease (Sun et al, 2002).The amount of phenolic compounds in grapes is influenced by the grape variety, along with viticultural and environmental factors (which are usually described by the French term "terroir"), which include soil type, geographical location and weather conditions (Douglas et al, 2001;Brescia et al, 2002;Xing et al, 2015). Temperature plays a direct and important role in the formation of phenolic compounds; temperatures higher than 30°C are not conducive to anthocyanin synthesis (Spayd et al, 2002;Tarara et al, 2008).…”

mentioning

confidence: 99%

Phenolic Compound Profiles in Grape Skins of Cabernet Sauvignon, Merlot, Syrah and Marselan Cultivated in the Shacheng Area (China)

Shi

Yue

et al. 2016

The phenolic compounds in the grape skins of Cabernet Sauvignon (CS), Merlot (ML), Syrah (SY) and Marselan (MS) from Shacheng, in China, were compared using HPLC-MS/MS. The results showed that the types and levels of phenolic compounds varied greatly with cultivars. Malvidin derivatives were the main anthocyanins. CS and ML showed a higher content of malvidin-3-O-(6-O-acetyl)-glucoside than malvidin-3-O-(trans-6-O-coumaryl)-glucoside, while SY and MS differed from CS and ML. ML had higher delphinidin and cyanidin derivatives, SY had higher peonidin derivatives, while malvidin and petunidin were higher in MS. The total content of flavonols, flavan-3-ols, phenolic acids and stilbenes in grape skins showed no difference among CS, ML and MS. Isorhamnetin-3-O-glucoside (CS, ML, MY), quercetin-3-O-glucoside (SY), procyanidin trimer (SY, MS), procyanidin dimer (CS, ML), syringetin-3-O-glucoside, trans-cinnamic acid and resveratrol were the most abundant non-anthocyanin phenolic compounds. Cluster analysis showed that CS and ML, and SY and MS had similar phenolic profiles. INTRODUCTIONPhenolic compounds in red grape skins are one of the most important parameters in determining red wine character and quality, and directly influence consumers' overall acceptance (Li et al., 2011). They contribute to the mouthfeel, colour and stability of red wines; some of them also exhibit potent biological activities (Gómez-Alonso et al., 2007). Phenolic compounds, mostly originating from grape berries, are transferred into wine during the winemaking process (Salas et al., 2003). The main phenolic compounds in red grapes and red wine are anthocyanins and non-anthocyanins, which include flavonols, flavan-3-ols, phenolic acids (including hydroxycinnamic acids and hydroxybenzoic acids) and stilbenes (Monagas et al., 2005;Li et al., 2011;Zhang et al., 2015). Anthocyanins, which are directly responsible for red grape and red wine colour (Mateus et al., 2002;Revilla et al., 2009), are composed of the monoglucosides of five anthocyanidins, namely delphinidin, cyanidin, petunidin, peonidin and malvidin, along with the corresponding acetyl, p-coumaroyl and caffeoyl derivatives (Liang et al., 2008;Raúl et al., 2009). Flavonols, which influence red wine coloration by co-pigmentation (Boulton, 2001), consist of the glycosides of myricetin, quercetin, kaempferol, isorhamnetin, syringetin and laricitrin (Raúl et al., 2009). The flavan-3-ols found in the skin and seed are mainly catechin, epicatechin, gallocatechin, epigallocatechin and their corresponding polymers. Flavan-3-ols are mainly responsible for the astringency, bitterness and structure of wines (Monagas et al., 2005), and they also play an important role in the stabilization of the red colour in wines (Sun et al., 2007). Stilbenes (mainly resveratrol) exhibit significant antioxidant properties in the prevention of arteriosclerosis and coronary heart disease (Sun et al., 2002).The amount of phenolic compounds in grapes is influenced by the grape variety, along with viticultural and environme...