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

Abstract

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...

Physicochemical and aromatic composition of 'Sauvignon Blanc' wines obtained from the Y-trellis and VSP training systems

“…Grapevine training systems have been widely studied, as they affect plant ecophysiology, vineyard productivity, grape quality (Hernandes et al, 2013;Würz et al, 2019), and wine sensory and phenolic characteristics (Fragasso et al, 2012). In addition, the choice of training system directly influences wine phenolic composition and volatile compounds (Liu et al, 2018).…”

Biochemical profile of ‘Niagara Rosada’ grapes under different rootstocks and training system

“…The quality of the grape is somehow related to the edaphoclimatic conditions, scion/rootstock compatibility (Silva et al, 2019) and training system. Furthermore, scion and rootstock have already been known to alter microclimate; thus, impacting on the yields and quality of the fruits (Liu et al, 2018). Also, the balance between vegetative and reproductive activity interferes in the bioactive compound concentrations, such as (poly)phenols in the final quality of grapes and their derivatives (Borges et al, 2013).…”

CHARACTERIZATION OF MERLOT DRY RED WINE COMPOSITION ACCORDING TO THE YEAR OF PRODUCTION. Scientific Bulletin. Series F. Biotechnologies, Vol. XXIII, 2019 ISSN 2285-1364, CD-ROM ISSN 2285-5521, ISSN Online 2285-1372, ISSN-L 2285-1364

“…In recent years, the popularity of red wine consumption has increased worldwide. Due to the increased content of phenolic compounds, primarily anthocyanins, leuco-anthocyanins, flavonols (quercetin) and flavan-3-ols (catechin and epicatechin) red wines are characterized by a high biological value (Liu et al, 2018;Motilva et al, 2016). Consumers demands for red wine quality the necessity of continuous improvement of technological processes of wine production.…”

“…They are contributing to bitter and astringent properties to the taste of fruits and fruit juices, due to the interaction of phenolic substances mainly procyanidins and glycoproteins. As well, these compounds are the main substances that can attribute the color differences in wines, juices, and products made from fruits and vegetables (Liu et al, 2018). Most of the components of the phenolic complex from grapes and wine belong to the group of biologically active substances, making red wines increasingly used to treat numerous Scientific Bulletin.…”