Article

Applied Water and Mechanical Canopy Management Affect Berry and Wine Phenolic and Aroma Composition of Grapevine (Vitis vinifera L., cv. Syrah) in Central California

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Abstract

A field study was conducted in north-central San Joaquin Valley of California to deduce the interactive effects of irrigation and mechanical canopy management on the phenolic composition of grape and wine, and volatile compounds of the wines produced from Syrah (Vitis vinifera L.). The irrigation treatments consisted of a grower control of 70% crop evapotranspiration (ETc) replacement (IRR-I) from anthesis to harvest, compared to a stronger plant water stress between fruit set and veraison with 50% ETc replacement, otherwise 70% ETc replacement rest of the season (IRR-II). Four canopy management treatments were crossed with the irrigation design. A control treatment was pruned by hand to 22 two-node spurs (C) with no further manipulation. Experimental canopy management treatments (CM) consisted in mechanically box pruning the vines to a 0.10 m hedge combined with 3 levels of mechanically shoot thinning: heavy shoot thinning (M1), light shoot thinning (M2) and no shoot thinning (M3). In this two-year study, the irrigation treatments had no impact on the canopy architecture, but mechanization treatments were effective. However, this study reports sensitivity of canopy management to weather conditions in previous and current year, therefore to vintage effect. The irrigation treatments affected berry composition more than mechanization, and the effect was insensitive of the vintage effect. The IRR-II reduced berry weight, resulting in reduced yield and crop load in both years but greater berry anthocyanins, tannins and total phenolics. For anthocyanins, this result was also confirmed on wine. One year was characterized by higher amount of precipitation at fruit set, and in this year the concentration in 3-isobutyl-2-methoxypyrazine was higher, but the concentration of terpenes and norisoprenoids was lower, with the exception of β-damascenone that was stable between years but increased with IRR-II. In typical years, where no precipitation is received in the San Joaquin Valley from fruit set to veraison, the M2 and IRR-II method may contribute to improve berry skin and wine phenolics as well as to reducing IBMP in wine while achieving high yields. This trial showed that precipitation can modulate the impact of cultural practices on grape and wine composition, and that lower irrigation amounts do not correspond to reduced wine quality even in the semi-arid and warm conditions of Central California.

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... Winter wines composition resemble that of Syrah wines from traditional regions, such as Australia (Antalick et al., 2015), Italy (Condurso et al., 2016), California (Brillante et al., 2018), and South Africa (Hunter and Volschenk, 2018) confirming the great potential of this technique for Brazilian viticulture. ...
... The presence of leafy and herbaceous aromas from C6 compounds such as cis-3-hexen-1-ol (928-96-1) released from the enzymatic degradation of lipids from grape cell membrane (Brillante et al., 2018) is related to fresh grape processing. Indeed this compound was found mainly at bottling in Syrah winter wines. ...
... The monoterpene linalool (78-70-6) and the ketone β-damascenone (23726-93-4) characterized as 'floral' and 'fruity' aromas were also present in winter wines, mainly at 30 months of ageing. Norisoprenoids, such as β-damascenone, are formed by an enzymatic reaction of carotenoids that are further subjected to catalytic reactions during wine ageing (Brillante et al., 2018). ...
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Double pruning extended the harvest season of wine grape (Vitis vinifera L.) to dry winter, enabling production of high quality wines in the southeastern Brazil. Winter harvest allows grapes to fulfill not only technological maturation, but also phenolic ripeness. Winter wines from Syrah grapes harvested from eight vineyards in southeastern Brazil during three harvests were analyzed for their chemical and aromatic composition after bottling and after ageing for 20, 30, and 42 months in bottle. Winter wines have high content of total phenolic compounds, which remained almost constant through ageing, as well as color intensity. Malvidin 3-O-glucoside stood out among anthocyanins, remaining 5-10 % after 39 months of ageing. Moreover, malvidin 3-O-glucoside-pyruvic acid was the main pyranoanthocyanin identified in winter wine. Polymerized pigments index ranged from 54 % at bottling to 80 % after 42 months of ageing. Young winter wines are rich in ester and monoterpene, as well as alcoholic volatile compounds responsible for ethereal, fruity, flowery, fresh and sweet aromas. Aged winter wines showed higher contents of furfural, geranyl ethyl ether, isoamyl decanoate, α-muurolene and α-calacorene, contributing to sweet, fruity and woody aromas. Syrah winter wines are characterized by high content of phenolic compounds and color stability, and keep good sensorial characteristics after ageing in bottle.
... Reported increases in phenolic compounds when water deficit occurs prior to véraison seem to be mainly due to concentration effects (Brillante et al., 2018;Santesteban et al., 2011). Only very few studies report an increase in anthocyanin content on a per berry basis (Koundouras et al., 2009;Ojeda et al., 2002;Ollé et al., 2011). ...
... Most studies dealing with the impact of water deficit on grape aroma compounds yield in very heterogeneous results. Regarding C13norisoprenoids such as beta-damascenone, betaionone, and 1,1,6-trimethyl-1,2-dihydronaphthalene most authors report a positive relation between their concentration and moderate to severe water deficit and consequently an increase of aroma potential, which is particularly true for red varieties such as for Cabernet-Sauvignon (Bindon et al., 2007;Brillante et al., 2018;Koundouras et al., 2009), Merlot (Song et al., 2012) or Tempranillo . In the latter study C6 compounds (hexanal, trans-2-hexenal, and 1-hexanol) and phenol volatiles, ethyl esters and lactones were also increased under water deficit. ...
... Regarding monoterpenes such as limonene, linalool, ±-terpineol and geranyl acetone several authors suggest that light to moderate water stress increase their concentration (Brillante et al., 2018) but as well their biosynthesis as indicated by transcriptomic studies, where moderate water deficit triggered terpenoid synthase expression in Chardonnay and Cabernet-Sauvignon (Deluc et al., 2011;Savoi et al., 2016). One of the few examples of aroma compounds where concentration in the berry is positively correlated with water availability (Geffroy et al., 2014) is the recently discovered sesquiterpene Rotundone (Wood et al., 2008), associated with peppery flavor in different red cultivars such as Syrah and Duras (Geffroy et al., 2018). ...
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The increasing risk of water deficit stress due to global warming subjects winegrowers of traditional rain fed viticulture regions to new challenges regarding vine water status assessment and possible drought mitigation strategies, such as irrigation. This review summarizes the most recent studies on the impact of water deficit stress on vine and berry physiology; it discusses the latest scientific advances regarding hormonal and hydraulic regulation and segmentation and addresses the current debate on iso/an-isohydricity within vine cultivars. Latest literature on irrigation frequency, water stress memory and the impact of abiotic factors such as VPD (Vapor Pressure Deficit), radiation, temperature and canopy architecture on vine physiology and water use, raise important questions on water status assessment and the implementation of irrigation strategies. Practical consequences regarding the effects of vine water regime on vine water regulatory mechanisms are discussed. Recent technical and scientific advances shed new light on how site specific irrigation strategies matching production objectives could improve vineyard water use.
... It has been widely reported that plant water status can influence the levels of phenolic compounds in grapes and wine (Deloire et al., 2004;Downey et al., 2006;Braidot et al., 2008). A detailed examination of the influence of viticulture practices on grape phenolic compounds was presented by Brillante et al. (2018). In this study, the authors determined that the application of water restrictions to grapevine has a higher influence on berry ripening than canopy management treatments with 3 levels of mechanically shoot thinning: heavy shoot thinning, light shoot thinning and no shoot thinning. ...
... Temporal variability in grapevine water status has been well documented (Chaves et al., 2007;Acevedo-Opazo et al., 2010a, 2010bZúñiga et al., 2018;Brillante et al., 2018). The evolution of plant water status along the season is a result of soil, weather, and plant management factors. ...
... 5). This finding is consistent with other studies that reported a clear impact of irrigation on plant water status(Chaves et al., 2007;Acevedo-Opazo et al., 2010a, 2010bZúñiga et al., 2018;Brillante et al., 2018). ...
Article
Improving wine composition is a critical factor for the wine industry. Phenolic compounds play an important role in wine composition contributing to its organoleptic characteristics. Although several factors can influence the phenolic concentration, plant water status in particular has shown to have a direct impact on the phenolic compounds. It is however complex to quantitate water deficit by plant water status measurements as they depend on the specific site (topography, viticultural management practices and soil characteristics) creating variable values within the vineyard block. This study focused on analysing the effect of natural spatial and temporal variability of plant water status on grape and wine parameters. A field experiment was done in a commercial Cabernet Sauvignon block to monitor the temporal and spatial intra-block variability of plant water status using a grid sample method. Soil analysis and topography were included in the evaluation. Each target vine was assessed for yield, ripeness as well as standard juice parameters. Micro-vinification was done for each target vine and the concentration of anthocyanins and tannins analysed. The results showed that the spatial and temporal variability was evident along the season. Plant water status influenced changes in the concentration of phenolic compounds and grape parameters. The vines in the stressed class were associated with changes in soil texture and topography. These plants presented a moderate increase (6.7%) in sugar content; a significant increase in anthocyanins (22.2%) and tannins (27.5%); and a strong reduction in yield (53.2%) when compared with the non-stressed classes. The results of this study may help to understand and quantify how spatial variability is naturally distributed and its effect on grape and wine parameters.
... Some reports showed an increase proanthocyanidin concentration and proanthocyanidin polymerization levels in grape berry skins Cáceres-Mella et al., 2017), and higher catechin levels (Zsófi et al., 2014). The observed increase of phenolic compounds when water deficit occurs prior to véraison can mainly be attributed to concentration effects (Santesteban et al., 2011;Brillante et al., 2018); however, several studies also observed an increase in anthocyanin content per berry (Ojeda et al., 2002;Castellarin et al., 2007a;Koundouras et al., 2009;Ollé et al., 2011). ...
... A positive relationship between increasing water deficit and the concentration of C13-norisoprenoids such as β-damascenone, β-ionone, and 1,1,6-trimethyl-1,2-dihydronaphthalene was reported. This was particularly true for red cultivars such as Cabernet Sauvignon (Bindon et al., 2007;Koundouras et al., 2009;Brillante et al., 2018), Merlot (Song et al., 2012), and Tempranillo . In of Talaverano et al. (2017), C6 compounds (hexanal, trans-2-hexenal, and 1-hexanol), phenol volatiles, ethyl esters, and lactones were also found to be increased under water deficit, as opposed to Song et al. (2012), which reported a decrease of those compounds under water deficit in Merlot. ...
... Several studies reported increased concentrations of monoterpenes such as limonene, linalool, α -terpineol geranyl acetone, geraniol, and citronellol under light to moderate water stress (Savoi et al., 2016;Brillante et al., 2018;Wang et al., 2019;Kovalenko et al., 2021), which was associated with increased expressions of terpenoid synthases-genes in Chardonnay and Tocai Friulano (Deluc et al., 2011;Savoi et al., 2016). Some authors report higher monoterpene concentrations, even under severe water deficit (Schüttler et al., 2015). ...
Article
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Temperature, water, solar radiation, and atmospheric CO2 concentration are the main abiotic factors that are changing in the course of global warming. These abiotic factors govern the synthesis and degradation of primary (sugars, amino acids, organic acids, etc.) and secondary (phenolic and volatile flavor compounds and their precursors) metabolites directly, via the regulation of their biosynthetic pathways, or indirectly, via their effects on vine physiology and phenology. Several hundred secondary metabolites have been identified in the grape berry. Their biosynthesis and degradation have been characterized and have been shown to occur during different developmental stages of the berry. The understanding of how the different abiotic factors modulate secondary metabolism and thus berry quality is of crucial importance for breeders and growers to develop plant material and viticultural practices to maintain high-quality fruit and wine production in the context of global warming. Here, we review the main secondary metabolites of the grape berry, their biosynthesis, and how their accumulation and degradation is influenced by abiotic factors. The first part of the review provides an update on structure, biosynthesis, and degradation of phenolic compounds (flavonoids and non-flavonoids) and major aroma compounds (terpenes, thiols, methoxypyrazines, and C13 norisoprenoids). The second part gives an update on the influence of abiotic factors, such as water availability, temperature, radiation, and CO2 concentration, on berry secondary metabolism. At the end of the paper, we raise some critical questions regarding intracluster berry heterogeneity and dilution effects and how the sampling strategy can impact the outcome of studies on the grapevine berry response to abiotic factors.
... Although this traditional training system facilitated production goals, such as mechanical harvesting, it was proven difficult to facilitate mechanical management, such as dormant pruning (Kurtural et al., 2012) and shoot removal (Terry and Kurtural, 2011), with some success in mechanical leaf removal (Cook et al., 2015;Yu et al., 2016). Previously, we investigated mechanizing dormant and growing season cultural practices on grapevine trained to common trellis systems used in California (Brillante et al., 2018;Kurtural et al., 2013Kurtural et al., , 2012Terry and Kurtural, 2011;Wessner and Kurtural, 2013) in vineyards trellised specifically for experimental purposes. However, there is a lack of information on how grapevines respond to conversion from headtrained and CP vineyards to mechanical management. ...
... The SHMP treatment did not alter berry composition when compared with the traditional systems. Previous studies reported similar findings in which mechanization of winter pruning or canopy management practices had no adverse effects on primary metabolites (Brillante et al., 2018;Geller and Kurtural, 2013;Terry and Kurtural, 2011). Similarly, systems that retained more buds with mechanical box pruning were able to minimize adverse effects on berry composition (Reynolds, 1998). ...
Article
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A field study was conducted for three consecutive seasons in the hot climate of central California USA to assess the performance of grapevine (Vitis vinifera L.) cultivar ‘Merlot’ grafted onto rootstock ‘Freedom’ during training system conversion to facilitate mechanization. The traditional head-trained and cane-pruned system was either retained (CP) or converted either to a bi-lateral cordon-trained, spur-pruned California sprawl training system (HP), or to a bi-lateral cordon-trained, mechanically box-pruned single high-wire sprawling system (SHMP). After the conversion, SHMP sustained greater yield with more clusters per vine and smaller berries without affecting the canopy microclimate. This was due to higher number of nodes retained after dormant pruning. The SHMP canopies, compared to CP and HP; filled allotted canopy space earlier based on photosynthetically active radiation transmitted through the canopies, populating the space allotted per vine, favoring higher production efficiency without affecting the long-term production goals. There were no adverse effects of training systems on berry composition or flavonoid concentration, during or after conversion to mechanical management. However, experimental year effect was obvious on anthocyanin composition of ‘Merlot’ berries, increasing tri-hydroxylated (i.e. delphinidin based) anthocyanins in the latter years of the experiment. Our results also provided evidence that earlier canopy growth coupled with sufficient reproductive compensating responses allowed for increased yields while reaching commercial maturity without a decline in anthocyanin content with the SHMP. Converting CP to SHMP reduced labor operations costs by 90%. Furthermore, the SHMP had greater gross revenue and resulted greater net income per acre even when the conversion year was taken into account. Therefore, SHMP is recommended for growers within the hot climate of the central San Joaquin Valley (SJV) as a means to maintain productivity of vineyards while not sacrificing berry composition at the farm gate.
... Under standard cultural practices in California vineyards, 140 to 220 L of irrigation water is used to produce 1 kg of wine grape (Martínez-Lüscher et al., 2017). Optimization of irrigation is not only important for environmental sustainability but also because it directly affects the yield and composition of grapes and wines (Castellarin et al., 2007;Brillante et al., 2017Brillante et al., , 2018a. The grapevine agronomic performance under mild water deficits is well documented (Chaves et al., 2010). ...
... Water savings and better agronomic performances could be obtained by reducing spatial heterogeneity in plant water status , avoiding local over-irrigation, and by better tailoring irrigation strategies (Brillante et al., 2018a). Routine measurements of plant water status in the field are timeconsuming and they must be constrained to few locations and time points, thus they do not easily allow a spatialized approach. ...
Article
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Carbon stable isotope composition of berry must at harvest (δ 13 C) is an integrated assessment of plant water status during grape (Vitis vinifera L.) berry ripening. Measurement of δ 13 C of grape juice is proposed as an alternative to traditional measurements of water status to capture the spatial variability of physiological response at the vineyard scale, i.e., zoning. We performed samplings at four different locations in California, United States, with three different cultivars of table and wine grapes (Cabernet Sauvignon, Merlot, Crimson-Seedless). Leaf physiology (photosynthesis, A N , stomatal conductance, g s) and stem water potentials (stem) were routinely measured. The δ 13 C was measured at harvest and strong relationships were found between stem (R 2 = 0.71), stomatal conductance (R 2 = 0.71), net carbon assimilation (R 2 = 0.59) and WUEi (R 2 = 0.53). The role of leaf nitrogen on the signal was assessed by evaluating relationships between leaf nitrogen and WUE i (R 2 = 0.54), Ci/Ca (R 2 = 0.51), δ 13 C (R 2 = 0.44), and stem (R 2 = 0.37). Although nitrogen can be among the environmental factors able to affect the δ 13 C signal, this difference is only observable when variability in N is very large, by pooling different vineyards/varieties, but not at the within-vineyard scale. The utility of δ 13 C was further tested and measured on grape berries sampled on an equidistant grid in a 3.5 ha vineyard where stem was also measured throughout the field season and used to delineate management zones. Physiological measurements and grape composition were correlated to soil electrical resistivity and satellite-derived vegetation index. The two management zones obtained by δ 13 C or stem were spatially similar at 67% and allowed to separate the harvest in two pools having statistically different grape composition (soluble solids, organic acids, and anthocyanin profiles). Zoning by δ 13 C performed as well as zoning by stem to separate grape phenolic composition, e.g., for selective harvest. Our results provided evidence that δ 13 C of grape must is a reliable and repeatable assessor of plant water status and gas exchange in vineyard systems that are crucial for zoning vineyards, even when irrigated, and for ground-truthing sensor maps in precision viticulture.
... Excess vine vigor was linked to deleterious effects on berry flavonoids (Baluja et al., 2012;Cook et al., 2015;Yu et al., 2016). This effect could be exacerbated with high nitrogen amounts inhibiting anthocyanin biosynthesis (Soubeyrand et al., 2014), the absence of water stress, or changes of cluster microclimate due to mutual shading (Keller et al., 2016;Brillante et al., 2018), and thus, not by the under cropping itself. Therefore, grapevine canopy development is managed through the control of inputs, vine spacing, irrigation, rootstocks, pruning, leaf removal, hedging, or cover crops, among others. ...
... Palliotti and Cartechini (1998) performed cluster thinning on three varieties over three seasons and found that cluster thinning did not affect must soluble solids. In years where rainfall was more abundant (Brillante et al., 2018), results of cluster thinning were compensated with larger berries (Wilson et al., 2014), with compensation of berry size similar to our results. Precisely, these kinds of results are those that disturbed the correlation between leaf area to fruit mass and berry total soluble solids (Supplementary Figure 2). ...
Article
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The grapevine (Vitis vinifera L.) is managed to balance the ratio of leaf area (source) to fruit mass (sink). Over cropping in grapevine may reveal itself as spontaneous fruit abortion, delayed ripening or as alternate bearing. The aim of this work was to study the same season and carry-over effects of manipulating source to sink ratios on grapevine phenology, leaf gas exchange, yield components, berry soluble solids accumulation and reserve carbohydrate and soluble sugar concentration in roots. Cabernet Sauvignon grapevines were subjected to defoliation (33%, 66% and 100% of the leaves retained) and fruit removal treatments (33%, 66% and 100% of clusters retained) arranged in a factorial design. Results from two seasons of source-sink manipulations were substantially different. In both seasons defoliation treatments affected season-long net carbon assimilation (AN) and stomatal conductance (gs) where the less leaves retained resulted in greater AN and gs and fruit removal had no impact on leaf gas exchange. In the first season, leaf area to fruit mass was hardly related to berry soluble solids and in the second season they were strongly correlated that suggested a degree of acclimation. Defoliation treatments had great impacts on berry size, berries per cluster and total soluble solids in both years. Fruit removal treatments only had effects on berry mass and berries per cluster in the first season, and only on berry soluble solids in the second. The predominant effect of defoliation (carbon starvation) cascaded onto reducing root starch content, root mass and delaying of veraison and leaf senescence, as well as harvest which was delayed up to 9 weeks with 33% of the leaves retained. In a third season, where grapevines grew without treatments, defoliation treatments had resultant carryover effects, including reduced leaf area, number of berries per cluster, clusters per vine, and yield but not on leaf gas exchange dependent on previous seasons’ severity of defoliation. Balancing source-to-sink ratio is crucial to obtain an adequate speed of ripening. However, this was the culmination of a more complex whole-plant regulation where the number of leaves (source strength) outweighed the effects of fruits (sink strength).
... Water stress significantly increases the content of non-acylated anthocyanins in wine (Liang et al. 2011). Weak light and water stress contribute to the improvement of grape peel and wine phenols, and to the reduction of methoxypyrazines in the wine while achieving high yields (Brillante et al. 2018). A water deficit affects the concentration of the total phenols, total anthocyanins and chromaticity (Cáceres-Mella et al. 2018). ...
Article
The eastern foot of Helan Mountains in Ningxia belongs to the semiarid area and has been identified as the best wine grape producing area in China. In order to solve the problems of a high sugar content, organic acid falling too fast and severe shortage of acidity in the berries during ripening, which lead to lack of wine harmony, this study took Vitis. vinifera L. cv. ‘Cabernet Sauvignon’ as the experimental material and expanded nine treatments from setting to harvest. Nine rows were selected and divided into three groups, treated with mild (–0.20 MPa ≥ Ψb ≥ –0.40 MPa), moderate (–0.40 MPa ≥ Ψb ≥ –0.60 MPa), severe (Ψb ≥ –0.60 MPa) water stress from setting to veraison separately. From veraison to harvest, within each group, the mild, moderate, severe water stress were set, forming light-light (CK), light-medium (T1), light-heavy (T2), medium-light (T3), medium-medium (T4), medium-heavy (T5), heavy-light (T6), heavy-medium (T7), heavy-heavy (T8) treatments. The results showed that when the medium treatment was used from setting to veraison and the medium or severe treatment was used during post-veraison to harvest, it would facilitate the transportation and accumulation of sugar and improve the fruit quality.
... The HPLC analysis also revealed that the levels of derivatives of anthocyanins (mainly malvidin 3-O-monoglucoside, the most abundant tri-hydroxylated anthocyanin) and flavonols (quercetin, miricetin) were significantly enhanced in wines from 161-49C. An increase in trihydroxylated anthocyanins, especially malvidin derivatives, has been observed also in other DI studies (Castellarin et al., 2007a, b;Santesteban et al., 2011;Brillante et al., 2018) and rootstocks studies (Koundouras et al., 2009), suggesting a shift in the anthocyanin biosynthesis pathway towards higher transcription levels of F3´5´H (rather than F3´H) and stimulation of the activity of the 3´O and 5´O methyltransferase enzymes, resulting in an increase in methylated anthocyanins, mainly malvidin (Romero et al., 2016b). In contrast, in Cabernet Sauvignon (CS), Bindon et al. (2008) found that PRI changed the methylation step of anthocyanin synthesis, increasing non-malvidin anthocyanins, while malvidin-glucosides were unaffected. ...
... The effects of solar exposure and canopy architecture (which is dependent on water balance) on the aroma profiles of wines have been previously reported, and they are consistent with the data presented in Figure 3. Specifically, these effects manifest through the influence of the microclimate within bunches [49], phenolic compounds [50,51], and the flavonol profile [52]. Due to the direct effect of bunch exposure to radiation in the aroma profiles obtained in wines, researchers have investigated the effect of defoliation as a management strategy to increase berry quality and aroma traits, which depends on the cultivar, timing of defoliation, and climatic region [53][54][55][56][57][58][59][60]. ...
Article
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Wine aroma profiles are determinant for the specific style and quality characteristics from final wines. These are dependent on the seasonality, mainly weather conditions, such as solar exposure and temperatures and water management strategies from veraison to harvest. This paper presents machine learning modeling strategies using weather and water management information from a Pinot Noir vineyard from 2008 to 2016 vintages as inputs and aroma profiles from wines from the same vintages assessed using gas chromatography and chemometric analyses of wines as targets. Results showed that artificial neural network models (ANN) rendered the high accuracy in the prediction of aroma profiles (Model 1; R = 0.99) and chemometric wine parameters (Model 2; R = 0.94) with no indication of overfitting. These models could offer powerful tools to winemakers to assess aroma profiles of wines before winemaking, which could help to adjust some techniques to maintain/increase quality of wines or wine styles characteristic of specific vineyards or regions. These models can be modified for different cultivars and regions by including more data from vertical vintages to implement artificial intelligence in winemaking.
... Shoot thinning can be carried out mechanically (Geller and Kurtural, 2013;Kurtural et al., 2013;Brillante et al., 2017), with little control over the type and number of shoots removed. More often studies have reported on manual shoot thinning with the number of shoots being adjusted to 12 to 20 per vine (Naor et al., 2002;Bravetti et al., 2012;Silvestroni et al., 2019;Silvestroni et al., 2016) to obtain a per metre shoot density of 8 to 15, depending on the vine spacing of the trial site. ...
Article
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Aim – Shoot thinning is a common canopy management practice used to obtain a desired canopy shoot density and improve the canopy microclimate. The cost of such technique, since it is often carried out manually, can be high. In this study the effect of severe shoot thinning (50% of shoots removed) applied at EL 15 was investigated by comparing yield components, canopy size, berry and wine chemistry and sensory attributes to a non-thinned control for the variety Semillon. Methods and Results – The trial was carried out over four seasons (starting in 2014-15) in the Semillon block of the Coombe vineyard (Waite Campus, the University of Adelaide). Canopy architecture was monitored at three phenological stages in each season and yield components were assessed at harvest. The harvested fruit was used for chemical and sensory analysis of the berries. Wines were made and their chemistry and sensory assessed. Results showed that shoot thinning affected the total leaf area only in two of the four seasons however the single shoot leaf area was higher in the shoot thinned vine. Similar results were obtained with pruning weight and cane weight. Shoot thinning did not reduce yield, despite a large reduction in bunch number, due to increases in bunch weight. Shoot thinning did not improve berry and wine chemistry. Similarly, little differences were observed in the sensory profile of berries and wines and only in the last season the assessors preferred the wines obtained from shoot thinned vines. Conclusions - Shoot thinning, in this study, failed to alter canopy architecture, yield and grape and wine chemistry. The vine balance indices leaf area/yield and yield/pruning weight were also unaffected by the treatment despite its intensity (50% of shoots removed). Significance and impact of the study – The practice of shoot thinning when applied at EL stage 15 (8-9 leaves separated) was not effective as a technique to improve canopy microclimate and berry and wine chemistry for Semillon in a hot Australian climate. Significant savings can be made if the use of this technique is better understood when applied in Australia. Further research is needed to explore the effect and timing of shoot thinning on other varieties and in different environments.
... Canopy management is normally used in grapevines to increase wine quality by modifying berry contents of phenolics, anthocyanins, and tannins (e.g., Gregan et al., 2012;González et al., 2015;Brillante et al., 2018). Our results suggest that canopy management does not seem to be a successful strategy for improving olive oil fatty acid composition in warm regions. ...
Article
The fatty acid composition of olive oil is greatly affected by geographical origin, and olive oil is often promoted by health experts because of its high oleic acid concentration. Unfortunately, recent evidence has shown that oleic acid (%) can be low in many non-Mediterranean regions due to high temperatures. Thus, management tools related to irrigation, fertilization, and canopy management are being sought that might improve fatty acid composition in such regions. The objectives here were to: 1) evaluate the relationships between fatty acid composition in fruit at different canopy positions and both the photosynthetically active radiation (PAR) and red-to-far red ratio (R/FR) measured at these same positions; and 2) determine the response functions of the fatty acid concentrations to PAR using multiple shading levels applied at different fruit growth phases. Fruit samples were taken from 60 canopy positions in a large olive hedgerow (cv. Arbequina) to achieve the first objective, and different shading levels (3, 20, 40, 70% PAR) were applied using shade cloth over the northern portion of large individual trees (cv. Arbequina) for the second objective. The oleic acid concentration (%) showed a significant exponential decay with increasing daily PAR values obtained from the different canopy positions. Maximum values of about 60% oleic acid were observed at low PAR and minimum values of 50% occurred at high PAR. Based on the artificial shading treatments, the high oleic acid at shaded canopy positions appeared to be related to less fruit maturation. The other main fatty acids did not differ by canopy position, and no significant relationships between individual fatty acids and R/FR ratio were found. However, severe artificial shading under shade cloth did increase stearic and linolenic acid concentrations. Despite oleic acid being about 10% higher in the more shaded parts of the canopy, cultivating olive trees at low PAR values in order to meet international olive oil trade standards would likely not be commercially feasible due to low flowering and yields. Careful cultivar selection, early harvesting when fruit are less mature and oleic acid is higher, and blending of oils from different cultivars are recommended to improve fatty acid composition in warm regions.
... Considering the means of each parameter for both treatments, data on winter wines' composition resemble that of Syrah wines from traditional regions such as Otaly (Condurso et al., 2016), South Africa (Hunter & Volschenk, 2018), California (Pinnell & Kurtural, 2012;Brillante et al., 2018), Spain (Gutiérrez et al., 2005;Gil et al., 2013) and Australia (Antalick et al., 2015). This confirms the great potential of the double pruning technique for Brazilian viticulture. ...
Article
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Sunlight and heating influence leaf and grape metabolism and therefore wine quality. As a recent management tool, no information exists on the effects of grapevine row orientation on the wine composition of Syrah vines within the context of double pruning management, a technique used to transfer the grape harvest from the wet summer to the dry winter season. This is a first attempt to investigate the wine composition from north-south- (NS) and east-west- (EW) oriented Syrah winter vines. EW wine samples had higher total acidity, residual sugars, alcohol and color hue, whereas NS wines exhibited higher content of color intensity, anthocyanins, total phenolics, total phenolic index, ashes and pH. The identification of volatile compounds was tentatively performed and demonstrated the presence of alkanes, volatile phenols and alkyl sulfide in NS wines, while butyrolactone and beta-damascenone were found mainly in EW wines. Row orientation contributed to wine composition and could be used as a management tool for obtaining individual wine styles.
... Water also has an important role in the production of high quality grapes. Grapevine grown under water deficit conditions are usually less vigorous, thus exposing grape bunches to more snlight, which leads to higher concentrations of norisoprenoids and monoterpenes (Deluc et al., 2009;Koundouras et al., 2009;Song et al., 2012), and lower concentrations of negative volatile compounds, such as C6 compounds, rotundone, and methoxypyrazines, leading to an increase in fruity aromas in grapes and wine (Zhanget al., 2015;Brillante et al., 2018). ...
Chapter
Volatile compounds are secondary metabolites that play a key role in the organoleptic properties of the grapes and wine. To this day, more than 700 volatile compounds have been identified in grapes and wine. The most important groups of volatile compounds are monoterpenes, C13-norisoprenoids, sesquiterpenes, alcohols, esters, ketones, aldehydes, fatty acids, methoxypyrazines and polyfunctional thiols. All volatile compounds are contained in the pericarp and their largest proportion is in the grape skin (exocarp). In grapes, they can be present in the free form and in the form of glycosides, most often in the form of diglucosides, with glucose as a unit directly linked to a non-sugar molecule, i.e., an aglycone. The aglycones can be monoterpenes, C13-norisoprenoids and volatile phenols. They are released from the berry during grape crushing by enzymatic hydrolisis or during vinification by chemical hydrolisis, and as such, in free form give the aroma of grapes and wines. Monoterpenes and C13-norisopreinods are synthesized in plastids but stored in vacuoles in the form of glycosides, which, unlike aglycones, are stable, soluble in water and can only be stored in aqueous media. Grapevines volatile composition is determined by the variety and can be influenced by biotic and abiotic factors and by different vineyard management practices. This chapter mainly concentrates in uniting the exisitng knowledge of the biosynthesis, composition and content of volatile compounds in different berry tissue and grape varieties.
... Some of the contaminants present in wine are extracted from the grape berries during the production process, and generally come from the soil where the vines grow (Sun et al. 2018). In this way, the elemental composition of grape berries, and consequently of wine, depends on the specific soil characteristics, the environmental conditions of the production area, the grapevine (Vitis Vinifera L.) variety, and the agronomic practices performed by the winegrower (such as rootstock, irrigation, fertilisation, leaf removing and tippings) (Brillante et al. 2018;Vitali Č epo et al. 2018;Sun et al. 2018). ...
Article
The accumulation of 20 elements in two autochthonous and one authorised txakoli grapevines (Vitis vinifera L.) commonly used in regional and European viticulture was investigated here over a two-year period, in order to understand how these elements are taken up, transported and stored, and to compare the results among the three grapevine varieties. Samples of the three grapevines were collected at four phenological growth stages (leaf development, flowering, fruit formation and ripening of berries). The concentrations of 20 essential, non-essential and toxic elements were measured by using ICP-MS. Most of the toxic elements were immobilised in the roots (P < 0.001, Al, As, Pb, Ti, V, Tl, Cr and Cd), which thus acted as a detoxification barrier against aboveground contamination. The main pool of essential elements was in the leaves (P < 0.001, Mg, Ca, Mn and Cu), which accumulate and transport micronutrients to other organs for the plants growth and development. The concentrations of non-essential and toxic elements in grape berries were low, especially at the time of harvesting (P < 0.05, richer in Fe, Na, Mg and K), which is important for food quality and safe wine production (Cd and Pb were far below the threshold established by theEuropean Commission 1886/2006). Riesling presented more effective mechanisms to accumulate Mn, Co, K and Fe (P < 0.05) in leaves and berries at the time of harvesting than those of autochthonous varieties, which corroborates the common origin of the latter. Understanding these growth- and variety-specific mechanisms is important for choosing the right grape for the production of a txakoli with specific elemental characteristics.
... Their values are like those reported in Table 2 at similar row and vine spacings and the measurements taken on 17 July 2000 (VSP trellis had 1.12 m 2 of shade/vine while the Lyre trellis had 2.32 m 2 . The maximum SA for a bilateral cordon trained vine with a sprawl canopy reported by Brillante et al. (2018) would be 2.53 m 2 /1.83 m row. This is slightly smaller than that for the bilateral cordon trained vines at KAREC of 2.82 m 2 (Table 3), 2.88 m 2 for the vines in Fig. 3 (and Table 3) and 2.76 m 2 for Merlot vines grown in the San Joaquin Valley (Williams, 2012a). ...
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Seasonal grapevine crop coefficients (Kc) were estimated from the shaded area (SA) beneath grapevine canopies at solar noon in vineyards with different trellises and row spacings. The trellises included the vertical shoot positioning (VSP) trellis, Lyre trellis, single and double curtains, cross-arms of varying lengths, and sprawl systems (shoots not positioned). Measurements were taken throughout the grape growing regions of California. The percent shaded area (PSA) was multiplied by 0.017, slope of the relationship between PSA and Kc, to calculate the Kc. Vines used to measure SA were not stressed for water as midday leaf water potential was ≥ −1.0 MPa. The seasonal increase in SA was significantly correlated with the accumulation of degree-days (DDs; base 10°C from the approximate date of budbreak) across locations and years. The PSA was a significant function of trellis – wider trellises spread the canopy and increased SA more than narrower trellises, thus having greater Kc values. The mid-season Kc (Kc mid) for the Lyre and VSP trellises on a 2.74 m row spacing were 0.96 and 0.49, respectively. In addition, Kc mid was inversely correlated with vineyard row spacing – the closer the row spacing for a particular trellis, the greater the Kc mid. The Kc mid for a VSP trellis on 1.83 and 3.05 m row spacings were 0.87 and 0.52, respectively. In contrast, the effects of vineyard row direction and location were minor. The seasonal Kc values developed here do not decrease from mid-season, even after harvest, with a few exceptions. Equations given herein express the seasonal Kc as a function of degree-days, trellis type, and row spacing, thus providing useful estimates of seasonal Kc values for use in California or elsewhere in vineyards with trellises like those in this study.
... Other studies also found no differences when mechanical pruning was applied (Main and Morris, 2008;Poni et al., 2004;Wessner and Kurtural, 2013). Some studies observed an increase in total anthocyanins, (Brillante et al., 2018;Holt et al., 2008, Zheng et al., 2017, but this is more likely due to a smaller berry size than to greater anthocyanin synthesis per unit area of berry skin (Zheng et al., 2017). There is a positive relationship between TSS and total anthocyanins ( Figure 4); therefore, as MEC grapes have lower TSS, they would also be expected to have lower total anthocyanins. ...
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Aim: The interaction of mechanized pruning systems and soil organic amendment can increase vine productivity. However, since the increase in productivity may affect grape composition, this study aimed to understand the effects of the interaction between these two practices.Methods and materials: Two field trials were implemented in Shiraz vineyards in two different wine regions. Mechanical hedge pruning was compared with hand spur pruning and four different organic amendments were tested: biochar, municipal solid waste compost, cattle manure and sewage sludge.Results: Mechanical pruning reduced the total soluble solids (TSS) and pH of the grapes, but had no effects on the other variables. Organic amendments also reduced TSS, especially sewage sludge, and tended to reduce total anthocyanins and total phenols. The effect of the interaction between both factors on grape composition was never significant. A negative relationship between yield and TSS was observed, while titratable acidity had no relationship with yield. Total anthocyanins were also negatively related to yield. A positive relation between TSS and total anthocyanins was also observed.Conclusions: The results show that the combination of mechanical pruning and soil organic amendment is a powerful tool for increasing productivity, but it has some effects on grape composition.Significance and impact of study: The reduction in some fruit composition variables showed that, while mechanical pruning does not significantly affect grape composition, the choice of type and amount of organic amendment will depend on the destination of the grapes.
... Despite the statistical observations, the intense trimming stands out among the tests because of the larger amount of total pigments and the TPI values reached (37.7% higher). In line with these observations, Brillante et al. [29] also observed higher pigment concentration with heavier canopy treatments. Comparing those results with the pH values measured in these cultivars, the slightly more acidic berries were produced with the more intense trimming treatment as well. ...
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Citation: Gutiérrez, N.; López-de-Silanes, L.; Escott, C.; Loira, I.; del Fresno, J.M.; Suárez-Lepe, J.A.; Morata, A. The Effect of Elicitors and Canopy Management in the Chemical
... In our study, water stress slightly affected skin phenolic compounds, and the differences in their concentrations were bigger between years. These results agree with those obtained by other authors [34,69,[72][73][74][75], who considered that an altered vine water status would affect the biosynthesis of flavonoids in skin only slightly, and its impact would not depend that much on the plant water status, but on the year [51,55,76]. In contrast, other studies have reported significantly higher concentrations of anthocyanins and tannins in grapes from stressed grapevines than in those obtained from non-stressed 'cabernet sauvignon' [77], 'tempranillo' [38], and 'merlot' cultivars [78] in the same year. ...
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Of all the abiotic stress types to which plants grown in fields are exposed, the most influential is water stress. It is well accepted that adopting controlled deficit irrigation strategies during the growing season has beneficial effects on the chemical compositions of grapes and red wines. However, there is a discrepancy in the timing, intensity and duration of deficit. This study aimed to evaluate the changes in phenolic composition of ‘merlot’ cultivar grapes when subjected to different levels of water stress in a semi-arid Mediterranean climate. Four treatments with different water stress levels were applied within two phenological intervals (flowering-veraison, veraison-maturity) to 128 grapevines for two consecutive years. The water stress levels for Treatments 1, 2, 3 and 4 were: no-light, light-moderate, moderate-intense and intense for the flowering-veraison and veraison-maturity intervals, respectively. Water stress distinctly affected the phenolic compounds in skin and seeds. The concentrations of flavan-3-ols and total polyphenols were much higher in seeds than in skin, and in both fractions, tannins are the major compounds.
... Different timing of water stress between the two years also impacted grape anthocyanins and polyphenols concentration. Generally, a higher water stress in red grapes is associated with higher total anthocyanin concentration (Calderan et al., 2021;Herrera et al., 2015;Sivilotti et al., 2005), but there are studies showing no correlation (Brillante et al., 2018;Herrera et al., 2017). In our study, total anthocyanin concentration was higher in 2019 than in 2018. ...
Article
Grapevines are being challenged by climate changes, forcing winemakers to implement irrigation systems to cope with excessive water stress. Previous studies focused on a small set of international varieties, and only few data are available for terroirs hosting cultivars with possibly different responses to drought stress. In this light, we monitored grapevine water status and grape’s physical and chemical composition, as well as concentration and structural characteristics of grape extractable polyphenols, in ten different Refoˇsk vineyards located in the Classical Karst terroir during 2018 and 2019. Grapevines did not suffer severe stress during the two years, but their response to water shortage periods was highly heterogeneous, as pre-dawn (Ψpd) and minimum (Ψmin) leaf water potential significantly differed between vineyards, especially during the drier part of the season. Moreover, the timing of maximum water stress differed in the two years, as in 2019 longer water shortage periods and higher temperature occurred at flowering stage and before veraison, while in 2018 they were higher after veraison. These differences influenced berry’s quality, as titratable and malic acid concentration in juice, as well as total anthocyanin, total polyphenols and higher high molecular weight proanthocyanidins (HMWP) concentration in skins, were higher in 2019 than in 2018. Regarding seed proanthocyanidins, HMWP concentration, mean degree of polymerisation (mDP) and percentage of galloylation (G) in seeds were higher in 2018 than in 2019. The differences in water status measured in spatially close-related vineyards strongly support the importance of monitoring grapevines’ water status dynamics to design adequate and effective water management activities rather than relying on climate data solely. Moreover, the timing of water shortage periods also played a role in determining Refosk grape quality. Our analyses showed that the higher (but still moderate, with Ψpd and Ψmin mean values around 􀀀 0.50 and 􀀀 1.25 MPa, respectively) water stress between veraison and harvest occurred in 2018 might reduce Refoˇsk grape acidity and increase concentration, polymerisation and galloylation of seed extractable proanthocyanidins.
... Similarly, an increase in proanthocyanidin concentration and proanthocyanidin polymerization along with higher catechin levels in grape berry skins have also been indicated by [126][127][128]. The increase in phenolic levels when water deficit occurred before veraison may be due to concentration effects [129,130] however, several other scientists discussed increase in anthocyanin content at berry level [110,113,122,131]. More focused research is needed to validate ribose, glyceric acid, citric acid, kaempferol-3-O-glucoside and quercetin-3-O-glucoside interactions as indicators of drought stress [132]. ...
Chapter
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Phenolics compounds in grapes contribute to berry and must color, organoleptic properties, nutritional value, antioxidant properties and provide protection against environmental challenges. Climate change has place mammoth challenges for the viticulture industry in different viticulture regions. Environmental variables determine to the greater extent, suitable grapes varieties for fresh as well as premium quality wine production. Grape berry composition is particularly affected by heat, drought, and intensity of solar irradiation. It is expected that climatic extremes will have an adverse effect on berry quality traits such as phenolic compounds in different grape cultivars. Polyphenols particularly anthocyanins decrease at elevated temperature, similarly flavanols levels increase with better exposure to solar radiation. Water availability is crucial for better vine growth and good production, however modest water stress particularly near veraison, upregulates the activity of key enzymes of the phenylpropanoid and flavonoid pathways. Therefore, it is important to know that how and when phenolic substance accumulate in berries and how various cultivars respond. This review elaborates the effect of weather conditions on biosynthesis of different phenolic compounds in grapes. Berry phenolic substances e.g., total phenolic compounds (TPC), total anthocyanins (TAC) and total flavonoid contents (TFC) synthesis is strongly regulated under the influence of environmental conditions during growing season. In this chapter we, shall focus on accumulation of phenolic compounds in grapevine in relation to climatic variations.
... In all the studied environments, the winter wine composition (which determines wine quality) was within the range of the composition of wines produced in different renown viticultural regions around the world; e.g., the alcohol content and pH values were similar to those found in California (Brillante et al., 2018); the alcohol content, anthocyanin and TPI values were similar to those in wines from Greece (Koundouras et al., 2006) and the anthocyanin values (Ristic et al., 2007), alcohol content and pH values were similar to those determined in wines from Italy (Priori et al., 2019). ...
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Southeastern Brazil is an emergent region in terms of the production of high-quality fine wines. To contribute to typicity assessment, the soils (morphology, mineralogy, chemical and physical analyses), parent material (geologic maps and portable X-ray fluorescence spectrometry) and climate (temperature and precipitation) were characterized in seven vineyards located in the state of Minas Gerais and São Paulo, Brazil, by carrying out state-of-the-art terroir analysis and assessing the environmental variations of the study sites. A soil profile was described and sampled in the central part of each vineyard. Principal Component Analysis (PCA) biplots were used to analyze the relationships between these factors and the composition of wines (2016, 2017 and 2018 harvests) produced from Syrah in commercial vineyards in different municipalities of Três Corações (TC), Cordislândia (COR), Andradas (AND), São Sebastião do Paraíso (SSP), Três Pontas (TP), Espírito Santo do Pinhal (PIN) and Itobí (ITO). The vineyards were grouped according to soil and climate characteristics. Group A was composed of COR, AND and PIN vineyards, which exhibited the highest correlation with soil Al 3+ content and accumulated rainfall. The group's wines had the lowest ash alkalinity, total polyphenol index (TPI) and pH values and the highest fixed acidity. Group B consisted of the TP and TC vineyards, which had the highest soil organic matter and boron contents and the highest thermal amplitude with similar values (15.4 °C in TC and 15.2 °C in TP); their wines showed average composition. Group C comprised ITO alone, which was characterized by the shallowest and least developed soils. Its wine had the highest flavonol content and high dry extract, color intensity, TPI, alcohol content and sugar values. Group D contained the SSP vineyard, in which the soil subsurface horizons were correlated with the highest wine pH. Late harvest in this vineyard caused the most dehydration of grapes and consequent concentration of most wine compounds (human effect on terroir). The terroir information produced in this study adds substantial value to the wines produced under the tropical environmental conditions of southeastern Brazil, for which such studies are very rare. By characterizing the natural factors (soil, soil parent material and climate) and human factors (vineyard management and wine characteristics) related to terroir, this study can also provide historical information about the wine from this emergent region (the historical factors). In addition, its results can be used to guide producers in their choice of vineyard cultivation sites according to preference in wine composition.
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Summary Aim: In wine grape production pruning, canopy management, and harvest are essential practices that are increasingly being done by machines. How well these practices are executed can substantially affect fruit yield and quality. Mechanization offers timeliness, uniformity, and cost benefits, but most methods available to date are non-selective and optimal execution requires careful attention to vineyard design, management, and machine settings. This review provides information to help growers make the best use of machines for these tasks. Key Themes: Vineyard design considerations Winter pruning Canopy management Harvesting Impact and Significance: The need to manage large vineyards in a contracting labor market is achievable with mechanization. This review summarizes the best practices in consideration of vineyard design, as well as operation of machines for optimal productivity for the wine grape grower. This review also provides information to help growers effectively incorporate the machines in their vineyards for consistent and economical production of wine grapes including pruning, shoot thinning, fruit zone leaf removal, crop load management, as well as mechanical harvest.
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Climate change models predict lower precipitation and higher air temperatures that will negatively affect viticultural regions. Irrigation of vineyards will be crucial for mitigating abiotic stress during the growing season. However, the environmental impact of irrigation requires consideration for ensuring its sustainability in the future. We evaluated the standard irrigation practices on grapevine water use efficiency, berry flavonoid composition, vineyard water footprint, and Arbuscular Mycorrhizal Fungi-grapevine symbiosis in two seasons with contrasting amounts of precipitation. The irrigation treatments consisted of weekly replacement of 25%, 50% and 100% of crop evapotranspiration (ETc) during two growing. Irrigation in grapevine vineyards mitigated the water scarcity when precipitation during the dormant season was not sufficient. The results provided field data supporting that despite the low rainfall recorded in one of the seasons, increasing the amount of irrigation was not advised, and replacing 50% ETc was sufficient. In this treatment, berry composition was improved with increased contents of TSS, anthocyanins and flavonols, and a stable flavonoid profile without an economic decrease in yield. In addition, with 50% ETc the mycorrhizal symbiosis was not compromised and water resources were not highly impacted. Altogether, our results provide fundamental knowledge for viticulturists to design an appropriate irrigation schedule under the future warming scenarios
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In commercial wine grape production, canopy management practices are applied to control the source-sink balance and improve the cluster microclimate to enhance berry composition. The aim of this study was to identify the optimal ranges of berry solar radiation exposure (exposure) for upregulation of flavonoid biosynthesis and thresholds for their degradation, to evaluate how canopy management practices such as leaf removal, shoot thinning and a combination of both affect the grapevine (Vitis vinifera L. cv. Cabernet Sauvignon) yield components, berry composition and flavonoid profile. Three experiments were conducted in Oakville, CA U.S.A. First experiment assessed changes in the grape flavonoid content driven by four degrees of exposure. In the second experiment, individual grape berries subjected to different exposures were collected from two cultivars (Cabernet Sauvignon and Petit Verdot). The third experiment consisted of an experiment with three canopy management treatments i) LR (removal of 5 to 6 basal leaves), ii) ST (thinned to 24 shoots per vine) and iii) LRST (a combination of LR and ST) and an untreated control (UNT). Berry composition, flavonoid content and profiles and 3-isobutyl 2-methoxypyrazine were monitored during berry ripening. Although increasing canopy porosity through canopy management practices can be helpful for other purposes, this may not be the case of flavonoid compounds when a certain proportion of kaempferol was achieved. Our results revealed different sensitivities to degradation within the flavonoid groups, flavonols being the only monitored group that was upregulated by solar radiation. Within different canopy management practices, the main effects were due to the ST. Under environmental conditions given in this trial, ST and LRST hastened fruit maturity; however, a clear improvement of the flavonoid compounds (i.e. greater anthocyanin) was not observed at harvest. Methoxypyrazine berry content decreased with canopy management practices studied. Although some berry traits were improved (i.e. 2.5 Brix increase in berry total soluble solids) due to canopy management practices (ST), this resulted in a four-fold increase in labor operations cost, two-fold decrease in yield with a 10-fold increase in anthocyanin production cost per hectare that should be assessed together.
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Grapevine productivity, and berry and wine flavonoid concentration, depend on the interactions of cultivar, environment, and applied cultural practices. We characterized the effects that mechanical leaf removal and irrigation treatments had on the flavonoid concentration of ‘Merlot’ (Vitis vinifera, L.) grape berries and wines in a hot climate over two growing seasons with contrasting precipitation patterns. Leaves were removed by machine, either pre-bloom leaf removal (PBLR), or post-fruit set leaf removal (PFLR), or not removed (control) and irrigation was either sustained deficit irrigation (SDI) at 0.8 of crop evapotranspiration (ETc) from budbreak to fruit set, or regulated deficit irrigation (RDI) at 0.8 ETc from bud break to fruit set, 0.5 ETc from fruit set to veraison, and 0.8 ETc from veraison to harvest, of ETc In 2014, PFLR reduced the leaf area index (LAI) compared to control. The RDI decreased season-long leaf water potential (Ψint) compared to SDI. However, in 2015, none of the treatments affected LAI or Ψint. In 2014, berry flavonoid concentrations were reduced by PBLR as well as SDI. SDI increased the flavonoid concentrations in wine, and PFLR increased some wine flavonols in one season. No factor affected the concentrations of wine proanthocyanidins or mean degree of polymerization. Thus, mechanical PFLR and RDI may increase berry flavonoid accumulation without yield reduction, in red wine grapes cultivars grown in hot climates when precipitation after bud break is lacking. However, spring precipitation may influence the effectiveness of these practices as evidenced by this work in a changing climate.
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Water availability is arguably the most important environmental factor limiting crop growth and productivity. Erratic precipitation patterns and increased temperatures resulting from climate change will likely make drought events more frequent in many regions, increasing the demand on freshwater resources and creating major challenges for agriculture. Addressing these challenges through increased irrigation is not always a sustainable solution so there is a growing need to identify and/or breed drought tolerance crop varieties in order to maintain sustainability in the context of climate change. Grapes, a major fruit crop of economic importance, have emerged as a model perennial fruit crop for the study of drought tolerance. This review synthesizes the most recent results on grapevine drought responses, the impact of water deficit on fruit yield and composition, and the identification of drought tolerant varieties. Given the existing gaps in our knowledge of the mechanisms underlying grapevine drought responses this review aims to answer the following question: How can we move towards a more integrative definition of grapevine drought tolerance?
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Wine final color, taste and aroma are closely related to the accumulation of secondary metabolites that may be affected by deficit irrigation applied in viticulture. A two-year study was conducted to assess the different fractions of crop evapotranspiration (ETc) irrigation replacement on wine composition, addressing the analysis of flavonoids and volatiles under context of global warming. Irrigating with 100% ETc (full grapevine demand) enhanced wine hue, antioxidant capacity, and some aromas; however, it came with a diminution of flavonoids and a less stable flavonoid profile. Replacing 25 and 50% ETc in wine grape improved wine color intensity, concentration of flavonoids, and shifted the aromatic profiles. These treatments increased some terpenes and esters which may enhance the desirable aromas for Cabernet Sauvignon, and decreased C6 alcohols related to unpleasant ones. Therefore, despite the warming trends in Mediterranean climates, 100% ETc irrigation would be not advisable to improve or maintain wine quality, and 50% ETc was sufficient.
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Harvesting fruit from horticultural species causes a down-regulation of photosynthesis but some species can recover after harvest. The objective of this study was to assess the hypothesis that the impact of fruit removal on the photosynthetic performance of Shiraz grapevines, in relation to CO2 concentration and leaf temperature, would contribute to a depreciation in photosynthetic assimilation. To assess this hypothesis, vines that were continuously vegetative were compared with vines that were harvested when fruit were ripe. These fruiting vines had higher rates of CO2-limited photosynthesis at all leaf temperatures compared to vegetative vines before harvest but after, photosynthetic rates were highest in vegetative vines. There were few treatment differences in CO2-saturated photosynthesis before harvest but after, below about 30°C, the harvested vines had higher photosynthesis than the vegetative vines. Maximum rates of ribulose 1,5 bisphosphate (RuBP) carboxylation and regeneration and responses to temperature were unaffected by differences in sink demand but after harvest, maximum rates increased, but markedly more in the vegetative vines, especially at higher temperatures. This conformed to higher photosynthetic rates in the vegetative vines. There were no sink demand effects on chlorophyll a fluorescence, consistent with the evidence that the fruit sink removal probably affected Rubisco activity and performance. The conclusion that sink removal caused a depreciation in photosynthesis was sustained but the temperature had a strong modulating effect through both stomatal and non-stomatal limitations driving the depreciation in assimilation. What was less clear was why assimilation of continuously vegetative vines increased during the harvest time when there were no apparent changes in sink demand.
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Majority of viticulture regions are located in mid-latitudes characterized by weather variability and stressful environments relying on irrigation for mitigating environmental stress during the growing season and to ensure a profitable yield. The aim of this study was to characterize the response of grapevine (Vitis vinifera L. cv. Cabernet Sauvignon) to different applied water amounts based on the replacement of fractions of crop evapotranspiration (ETc) during two growing seasons with contrasting precipitation patterns. The experiment consisted of three irrigation treatments based on the weekly replacement of 25%, 50% and 100% of ETc. Grapevine stem water potential decreased during the growing season reaching its lowest value (-1.5 and -1.2 MPa, respectively) at harvest in the more stressed vines (25% and 50% ETc). Leaf gas exchange variables were measured during the two seasons and 100% ETc had the highest rates of photosynthesis, stomatal conductance and better instantaneous water use efficiency; also resulting in higher leaf chlorophyll and carotenoid content. Mineral nutrient content for nitrogen and potassium increased linearly with the increase in applied water. At harvest, no differences were observed in the number of clusters per vine; however, the 25% ETc had the lowest berry size and yield per vine with no difference in sugar content of berry. Conversely, sugar allocation to reserve organs was highly affected by applied water leading to different shoot to root biomass partitioning where shoot:root ratio, leaf non-structural carbohydrates, and photosynthetic pigments increased with greater applied water. Likewise sucrose:N ratio and root non-structural carbohydrates decreased with the lower applied water. Altogether, carbon allocation between source and sink organs likely controlled the response of grapevines to water deficits in a hot climate, and replacing 50% ETc was sufficient to sustain the grapevine performance given the enhancement of sugar transport, that could slow down the detrimental effect of water deficits on yield.
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Wine aroma strongly influences wine quality, yet its composition and its evolution during the winemaking process are poorly understood. Volatile compounds that constitute wine aroma are traditionally divided into three classes according to their origin: grape, fermentation, and maturation aroma. We challenge this view with meta-analysis and review of grape and wine volatiles and their precursors from 82 profiling experiments. We compiled a list of 141 common grape and wine volatiles and quantitatively compared 43 of them. Our work offers insight into complex relationships between biosynthesis of aroma in grapes and the changes during the winemaking process. Monoterpenes are one of the largest and most researched wine aroma compounds. We show that their diversity in wines is mainly due to the oxidative metabolism of linalool in grapes. Furthermore, we demonstrate that most of the linalool produced in grapes is converted to these oxidized derivatives.
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Background Volatile thiols largely contribute to the organoleptic characteristics and typicity of Sauvignon blanc wines. Among this family of odorous compounds, 3-sulfanylhexan-1-ol (3SH) and 4-methyl-4-sulfanylpentan-2-one (4MSP) have a major impact on wine flavor. These thiols are formed during alcoholic fermentation by the yeast from odorless, non-volatile precursors found in the berries and the must. The present study investigates the effects of vine nitrogen (N) status on 3SH and 4MSP content in Sauvignon blanc wine and on the glutathionylated and cysteinylated precursors of 3SH (Glut-3SH and Cys-3SH) in the berries and the must. This is paralleled by a RNA-seq analysis of gene expression in the berries. The impact of N supply on the expression of the glutathione-S-transferase 3 and 4 (VviGST3 and VviGST4) and the γ-glutamyltranspeptidase (VviGGT), considered as key genes in their biosynthesis, was also evaluated. ResultsN supply (N100 treatment) increased the 3SH content in wine while no effect was noticed on 4MSP level. Furthermore, N supply increased Glut-3SH levels in grape berries at late berry ripening stages, and this effect was highly significant in must at harvest. No significant effect of N addition was noticed on Cys-3SH concentration. The transcript abundance of the glutathione-S-transferases VviGST3 and VviGST4 and the γ-glutamyltranspeptidase (VviGGT), were similar between the control and the N100 treatment. New candidate genes which might be implicated in the biosynthetic pathway of 3SH precursors were identified by whole transcriptome shotgun sequencing (RNA-seq). Conclusions High vine N status has a positive effect on 3SH content in wine through an increase of Glut-3SH levels in grape berries and must. Candidate GSTs and glutathione-S-conjugates type transporters involved in this stimulation were identified by RNA-seq analysis.
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Vitis vinifera cv. Carmenere, a member of the Cabernet family, was recently rediscovered in Chile where it had been misidentified as Merlot. The Carmenere variety produces complex wines, marked with herbaceous and "green" aromas. Results indicate that methoxypyrazines are present in high concentrations in this variety, probably responsible for the strong vegetative character found in Carmenere wines. Wines from Carmenere grapes had high 3-isobutyl-2-methoxypyrazine (IBMP) concentrations (5.0 to 44.4 ng/L), much higher than most Cabernet Sauvignon wines. The genotype dramatically affected the methoxypyrazine content of Carmenere wines, with some clones containing three-fold more than others. Climatic conditions, rather than maturity or terroir, had a critical effect upon IBMP concentration in grapes. 3-Isopropyl-2-methoxypyrazine evolved differently during grape maturation and was less influenced by harvesting year. Copyright © 2007 by the American Society for Enology and Viticulture. All rights reserved.
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The influence of solar radiation and temperature on the accumulation of berry skin anthocyanins was evaluated in Vitis vinifera L. cv. Nebbiolo during ripening. In 2006 and 2007, five fruit-zone light exposure regimes were established using plastic netting or leaf removal. Shading was applied in three periods: from fruit set to veraison, from fruit set to harvest, and from veraison to harvest. Fruit-zone shading had no impact on yield per vine and cluster weight, but early fruit-zone shading caused a slight delay in berry development, although it did not lead to lower berry size at harvest. Fruit-zone shading reduced total soluble solids and anthocyanin accumulation. Generally, fruit shading decreased the 3′-hydroxylated anthocyanin concentration and increased the 3′,5′-hydroxylated anthocyanin concentration. Fruit-zone leaf removal caused a delay of berry development, but did not affect berry size, cluster weight, or yield at harvest. Excessive sunlight exposure caused sunburn damage and did not increase total soluble solids or anthocyanin accumulation.
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Quantity and characterization of flavonoids were determined in skins isolated from Vitis vinifera L. cv. Cabernet Sauvignon berries during fruit ripening and at different postveraison water deficits. The per berry amount of anthocyanin, flavonol, and pigment incorporation into proanthocyanidins increased with maturity. The amount of proanthocyanidin extension subunits did not vary with maturity, although the extension subunit composition did. The apparent average degree of polymerization of proanthocyanidins increased with maturity. Incorporation of pigmented material into the proanthocyanidins, together with the apparent increase in average degree of polymerization, suggests that additional terminal subunits, which are not flavan-3-ols, accumulate during fruit ripening. Increased vine water deficit caused small increases in anthocyanins and decreases in flavonols. Red wine flavonoid amounts indicate that postveraison water deficits affect red wine flavonoids primarily by altering berry size and perhaps secondarily by modifying flavonoid biosynthesis.
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The influence of solar radiation and temperature on the accumulation of berry skin anthocyanins was evaluated in Vitis vinifera L. cv. Nebbiolo during ripening. In 2006 and 2007, five fruit-zone light exposure regimes were established using plastic netting or leaf removal. Shading was applied in three periods: from fruit set to veraison, from fruit set to harvest, and from veraison to harvest. Fruit-zone shading had no impact on yield per vine and cluster weight, but early fruit-zone shading caused a slight delay in berry development, although it did not lead to lower berry size at harvest. Fruit-zone shading reduced total soluble solids and anthocyanin accumulation. Generally, fruit shading decreased the 3′-hydroxylated anthocyanin concentration and increased the 3′,5′-hydroxylated anthocyanin concentration. Fruit-zone leaf removal caused a delay of berry development, but did not affect berry size, cluster weight, or yield at harvest. Excessive sunlight exposure caused sunburn damage and did not increase total soluble solids or anthocyanin accumulation.
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An experiment was conducted in central California on Merlot to determine the interaction of mechanical leaf removal (control, pre-bloom, post-fruit set) and applied water amounts [sustained deficit irrigation (SDI) at (0.8) and regulated deficit irrigation (RDI) at 0.8 (bud break-fruit set) – 0.5 (fruit set-veraison) – 0.8 (veraison-leaf fall) of estimated vineyard evapotranspiration (ETc) on productivity and berry skin anthocyanin content, composition and its unit cost per hectare. The pre-bloom leaf removal (applied ~100 GDD prior to bloom) treatment consistently maintained at least 20% of photosynthetically active radiation in the fruit zone in both years of the study, while post-fruit set leaf removal was inconsistent across years. The RDI treatments reduced berry mass, while the post-fruit set leaf removal treatment reduced berry skin mass. The pre-bloom treatment did not affect yield in either year. Exposed leaf area and leaf area to fruit ratio (m2/kg) were reduced with leaf removal treatments. The RDI treatment consistently advanced Brix in juice. Anthocyanin concentration was improved with pre-bloom leaf removal in both years while irrigation treatments had no effect. Proportion of acylated and hydroxylated anthocyanins were not affected by leaf removal treatments. In both years SDI increased di-hydroxylated anthocyanins while RDI increased tri-hydroxylated anthocyanins. Pre-bloom leaf removal when combined with RDI optimized total skin anthocyanins (TSA) per hectare while no leaf removal and SDI produced the least. The cost to produce one unit of TSA was reduced 35% with the combination of pre-bloom leaf removal and RDI treatments when compared to no leaf removal and SDI. This study provides information to red wine grape growers in warm regions on how to manage fruit to enhance anthocyanin concentration and the proportion of hydroxylation while reducing input costs through mechanization and reduced irrigation.
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A field study was conducted from 2007 to 2010 to examine regional and seasonal variability of the main compounds responsible for green aromas in grapes and wines, 3-isobutyl-2-methoxypyrazine and C-6 compounds. Sixty-nine commercial Vitis vinifera L. Merlot vineyards located in three distinctly different winegrape growing regions within the Central Valley of California were sampled at commercial harvest, fruit samples were analyzed for green aroma compounds and standard chemometrics, and several weather parameters such as growing degree days and rainfall were recorded at the vineyard level. Seasonal variation was found to be more important than regional variation, and similar trends among regions were found within each season. Temperature during the spring, a period of active growth, was found to be a significant driver of fruit green aroma compounds at harvest, likely due to its interactions with vine vigor and fruit shading.
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Abstract Volatile organic compounds are vital to wine quality, determining their aroma and varietal characteristics. Which are present, and in what quantity, depends on the cultivar, the situation and soil of the vineyard, weather, cultivation methods, and winemaking practices. Here we review the literature on the development of wine aroma compounds in grapes, and how it is affected by the above-named factors. Increasing understanding of these processes at the molecular level will aid vine growers in the optimal selection of harvest dates and other decisions favouring the consistent production of balanced, flavourful berries.
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A study was conducted to determine the key environmental and viticultural variables affecting the concentration of 3-isobutyl-2-methoxypyrazine (IBMP) in Cabernet franc grapes. Berries were sampled from individual vines at 30 days after anthesis (DAA), 50 DAA, and harvest from 10 and 8 commercial New York State vineyards in 2008 and 2009, respectively. IBMP concentrations at 50 DAA were significantly higher in the warmer 2008 growing season (2008, 103 to 239 pg/g; 2009, 12 to 87 pg/g). However, in the cooler 2009 growing season a smaller percent decrease in IBMP from 50 DAA to harvest was observed, so that IBMP at harvest was not significantly different between years (2008, 1 to 13 pg/g; 2009, 5 to 14 pg/g). IBMP accumulation up to 50 DAA and log-fold decrease of I BM P from 50 DAA to harvest was modeled as a function of >120 viticultural and environmental variables (122 in 2008 and 140 in 2009). Important variables identified for modeling IBMP at 50 DAA were those associated with vine vigor, which was positively correlated with IBMP accumulation. Cluster light exposure did not explain differences in IBMP accumulation across sites, but it was important for modeling smaller differences within some sites. IBMP decrease could not be satisfactorily modeled across multiple sites, but within sites the decrease was most consistently correlated with classic fruit maturity indices (total soluble solids [TSS], TSS*pH(2)). The intensity of herbaceous aromas in wines produced from each site was not correlated with IBMP concentration, but multivariate models indicated that lower vine water status was the best predictor of increased herbaceousness.
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A study was conducted in the San Joaquin Valley of California on Merlot to determine the interaction of applied water amounts [at 0.4, 0.8, and 1.2 of estimated vineyard evapotranspiration (ETc)] and leaf removal (at berry set or veraison) in the fruiting zone on productivity. Shaded area was measured beneath the canopy of the 1.2 irrigation treatment at solar noon throughout the study to provide an estimate of seasonal crop coefficients (K c). Vine water status was assessed across treatments and years by measuring midday leaf water potential (Ψl). The maximum K c determined from the percent shaded area was 0.7 at the row spacing of 3.66 m and canopy type that developed a “California Sprawl.” Irrigation treatment had a significant effect on midday Ψl and no such effect for leaf removal. Clusters exposed to direct solar radiation had significantly higher temperatures and lower cluster Ψ than clusters in the shade. Irrigation treatment had a significant effect on berry weight, soluble solids, and titratable acidity. Yields of vines significantly increased as applied water amounts increased. In this wine grape production area, profitability is dependent upon yield. This study provided a reliable estimate of ETc and applied water amounts to maximize yield.
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Canopy architecture, yield components, fruit composition, and vigor of Syrah were measured in response to four canopy management and three regulated deficit irrigation (RDI) treatments. The control consisted of dormant hand pruning to 22, two-node spurs (HP) with no further manipulation. Other treatments consisted of mechanically box pruning vines to 10 cm hedges and mechanically thinning the canopy to a density of 5 (CLL) or 7 (CLM) count shoots per 30 cm of row or mechanically box pruning to a 10 cm hedge with no shoot thinning (CLH). Control vines were irrigated to 70% of evapotranspiration (ET(0)) from fruit set until harvest (RDIC). Other vines either received 70% of full vine ET until veraison and 50% of ET(0) (RDIL) thereafter or received 50% of ET between fruit set and veraison (RDIE) and 70% thereafter. Mechanical shoot thinning (CLM) removed 25% of the total shoots, exposing 70,600 shoots.ha(-1) with a distance of 4.6 cm between count shoots on the cordon, which translated to four leaf layers and 12.6 m(2) leaf area. The combination of the CLM and RDIE decreased, berry weight at harvest by 12% without decreasing yield compared to HP, resulting in 21.5 tons.ha(-1) yield. A combination of CLM and RDIE was needed to achieve vine balance with a crop load of 9.9 kg yield/kg pruning weight and a leaf area to fruit ratio of 0.75 m(2).kg(-1). The study identified a canopy management method that can be used in combination with regulated deficit irrigation that reduces input costs through mechanization and enhances berry composition with a vine balance that provides sustainable production.
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Potassium (K) is essential for vine growth and yield. Grape berries are a strong sink for K, particularly during ripening. Excess K levels in grape berries may have a negative impact on wine quality, mainly because it decreases free tartaric acid resulting in an increase in the pH of grape juice, must and wine. In Australia, high K status is common in most vineyards, which reflects the high K and high pH values of most Australian grape juice. This necessitates pH adjustment during the vinification process, and tartaric acid addition is a common practice in most Australian wineries. High K concentration may also lead to excessive loss of the additional tartaric acid by precipitation as potassium bitartrate and, as a consequence, pH adjustment becomes more difficult and expensive. Ensuring naturally low K levels in the berry will help reduce costs of input and waste management at the winery. Potential vineyard management options to manipulate berry K accumulation include selective use of rootstock/scion combination, canopy management and irrigation strategies. However, the impact of these practices on determining the optimum K concentration requires careful calibration of production parameters and the desirable grape juice and wine quality in relation to tissue K concentration. This paper reviews and discusses the possible functions of K in grape berries, translocation of K into the berry, and genetic and cultural factors that may affect the accumulation of K in the berry. This will help to identify the key research and management strategies needed for controlling K concentrations in grape berries.
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Wine is made up of more than one thousand compounds, the majority of which, such as vitamins and minerals, come from the grapes, while others, like ethanol and glycerol, are products of the winemaking process. Although sugars are either partially or completely transformed, sugar import and accumulation into the ripening berry is a major parameter of wine quality. Sugar status is directly related to the final alcoholic content of wine, and regulates several genes responsible for the development of its aromatic and organoleptic properties. Physiological ripeness is reached when the grapes achieve sufficiently high sugar levels without loosing too much acidity; however, aromatic and phenolic compound content must also be taken into account. Softening and water content are other essential characteristics of a ripe berry. From a winemaker point of view, optimal grape maturity is essential for wine quality, but is difficult to assess because it is under multifactorial control, involving grapevine cultivar variety and environmental parameters such as soil, temperature, exposure to sun, and hormonal regulation. Continued study of the key control points in grape ripening is crucial if we ultimately hope to improve grape and wine quality.
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The effects of several moderate irrigation regimes on vine water status, yield, and must and wine composition, were investigated during five seasons in a vineyard planted with Vitis vinifera cv. Tempranillo. Treatments consisted of non-irrigated vines and six differentially irrigated treatments with contrasting watering regimes during the pre-veraison and post-veraison periods. There were large differences in yield and grape and wine quality responses to irrigation among seasons, probably as consequence of the different environmental conditions and crop levels. It was, however, clear that vines benefit more of the irrigation supplied in years of high yield levels. Across seasons, yield increased in proportion to the amount of water applied mostly due to the larger berries of irrigated vines, and there was no clear response to the timing of irrigation supplied. In addition, there were no carry over effects due to irrigation on bud fertility. The post-veraison water application was necessary to increase must sugar level and wine alcohol content. However, water restrictions during the pre-veraison period lead to more concentrated berries in terms of total phenolic and anthocyanins. The only noticeable detrimental effect of irrigation, regardless of the timing of its application, on wine composition was an increase in wine pH.
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The roles of light and temperature in the accumulation of the vegetal impact compound 2-methoxy-3-isobutylpyrazine (MIBP) in grape (Vitis vinifera L.) berries were determined. Individual clusters were exposed to various light intensities using neutral density shade cloth before ripening, during ripening or throughout the season in three growing seasons. A recently developed method using headspace solid-phase microextraction combined with GC-MS in the selected ion-monitoring mode was employed to measure MIBP in berries. Berry MIBP concentration increased subsequent to berry set, reached a maximum prior to onset of ripening, and then decreased thereafter until harvest. Complete shading of clusters increased the concentration of MIBP more than 100% compared to unshaded controls in 2 out of 3 years. Light increasingly inhibited MIBP concentrations up to 25-50% of ambient light intensities (1500 µmol photons m(-2) s(-1) ). However, only changes in light intensity before ripening had any effect on MIBP accumulation or final MIBP concentration. Analyses of weather data showed that the 1 year in which shading was ineffective was unusually warm, warm early in the season, and had more hot days and higher early season degree days than the other 2 years. In controlled environment experiments, warm growth conditions reduced MIBP concentrations in fruit about as much as light exposure reduced MIBP concentrations in the field experiments. The results indicate that both light and temperature significantly affect MIBP in harvested fruit, but that the light environment during ripening does not significantly affect MIBP concentrations in the berries at harvest.
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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
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The relationships between variations in grapevine (Vitis vinifera L. cv. Merlot) fruit zone light exposure and water deficits and the resulting berry flavonoid composition were investigated in a hot climate. The experimental design involved application of mechanical leaf removal (control, pre-bloom, post-fruit set) and differing water deficits (sustained deficit irrigation and regulated deficit irrigation). Flavonol and anthocyanin concentration was measured by C18 reversed- phased HPLC and increased with pre-bloom leaf removal in 2013, but with post-fruit set leaf removal in 2014. Proanthocyanidin isolates were characterized by acid-catalysis in the presence of excess phloroglucinol followed by reversed-phase HPLC. Post-fruit set leaf removal increased total proanthocyanidin concentration in both years while no effect was observed with applied water amounts. Mean degree of polymerization of skin proanthocyanidins increased with post-fruit set leaf removal compared to pre-bloom while water deficit had no effect. Conversion yield was greater with post-fruit set leaf removal. Seed proanthocyanidin concentration was rarely affected by applied treatments. The application of post fruit-set leaf removal, regardless of water deficit increased the proportion of proanthocyanidins derived from the skin, while no leaf removal or pre-bloom leaf removal regardless of water deficits increased the proportion of seed-derived proanthocyanidins. The study provides fundamental information to viticulturists and winemakers on how to manage red wine grape low molecular weight phenolics and polymeric proanthocyanidin composition in a hot climate.
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Atmospheric carbon dioxide (CO2) levels and temperature are expected to increase in the next decades. In addition, changes in climate as well as the stratospheric ozone concentration may affect the exposure of viticultural regions to UV-B. The aim of the present study was to investigate the effect of combined elevated CO2 and increased temperature (+CO2/+T) regimes and UV-B radiation on anthocyanin and flavonol biosynthesis in grape berries. Three UV-B doses [0, 5.98 and 9.66 kJ/(m2·d)] and two CO2–day/night temperature regimes (390 μmol/mol CO2–24/14°C and 700 μmol/mol CO2–28/18°C) were imposed on Vitis vinifera cv. Tempranillo fruit-bearing cuttings from fruitset to maturity. Berry mass, composition and expression of selected genes were monitored. The time to reach veraison and maturity was reduced under +CO2/+T. Anthocyanin concentration under +CO2/+T was higher 2 weeks after veraison, but lower at maturity. Ultraviolet-B radiation slowed berry development and upregulated flavonol and anthocyanin biosynthesis. The effect of UV-B, which modulates the accumulation of sugars and upregulates anthocyanin biosynthesis, compensated the deleterious effect of elevated CO2 and increased temperature on berry anthocyanin concentration. Certain viticultural practices, such as leaf removal, that modify the exposure of grapes to UV-B and the leaf surface to fruit mass ratio, may alleviate the effect of elevated CO2 and increased temperature on grape anthocyanin concentration.
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A trial in the San Joaquin Valley of California investigated how the interaction of pruning systems and mechanical shoot thinning affected canopy performance, yield components, fruit phenolic composition at harvest, and production efficiency of a procumbent cultivar in a warm climate grape-growing region. Two pruning systems and three shoot thinning treatments were arranged factorially in a randomized complete block design with four replications. The pruning methods were applied by either handpruning to a target of 25 nodes/m or mechanically hedging and retaining a 100-mm spur height. The shoot density treatments were applied mechanically at a modified Eichhorn-Lorenz scale, stage 17 to retain 40 or 45 shoots/m of a row, or left unthinned. The contribution of count shoots to total shoots increased when mechanical box pruning replaced spur pruning. The contribution of percent count shoots to total shoots was greatest with 40 shoots/m and unthinned treatments. The percent photosynthetically active radiation (PAR) transmission and percent canopy gaps increased with mechanical box pruning and also with the decrease in shoot density per meter of row. Berry and cluster size decreased with mechanical box pruning application. However, because mechanically box-pruned vines carried more clusters, yield per meter of row increased. There was a quadratic response to shoot thinning where berry skin phenolics, anthocyanins, and tannins decreased with the 45 shoots/m treatment when compared with 40 shoots/m and unthinned treatments. Pruning weight per meter of row and leaf area-tofruit ratio decreased, whereas Ravaz Index (kg yield/kg pruning weight) increased with mechanical box pruning. Shoot thinning treatments did not affect pruning weight per meter of row or leaf area-to-fruit ratio. Increasing amount of PAR and percent canopy gaps by shoot thinning resulted in vegetative compensation from a sparsely populated grapevine canopy, thereby negating its purported effects. The 40 and 45 shoots/m treatments repopulated the canopy rapidly with non-count shoots thereby increasing the pruning weight per meter of row at the end of the season. In the absence of a physiological response, shoot thinning in a procumbent cultivar is not recommended. Mechanically box pruning to a 100-mm spur height and slowing down vegetative growth by irrigating to 50% of daily evapotranspiration (ETo) variance between fruit set and veraison have resulted in a Ravaz Index window (5 to 10 kg·kg-1) and is recommended for procumbent red wine grape cultivars for the region with similar or better berry skin phenolic accumulation than spur-pruned vines.
Article
Sixteen California Cabernet Sauvignon wines were chosen to represent a spectrum of vegetal aroma characteristics. Sensory analysis by descriptive analysis profiling and experts' groupings of the wines by similarity of aroma were completed for the wines. All wines were found to be significantly different from one another for all aroma terms rated by the descriptive panel, including the vegetal terms eucalyptus, bell pepper, olive, and cooked vegetable. The expert winemakers/enologists sorted the same wines into groups by three different similarity criteria: first, by similarity according to their own individual criteria; second, by intensity of vegetal aroma; and third, by intensity of sulfur defects. Comparison of the results from descriptive analysis and the expert panel sorting data revealed similarities in the classification of vegetal aromas for these wines regardless of the criteria used for sorting. Methoxypyrazines, typically associated with vegetal aromas, were also measured for these wines and were not correlated with any of the descriptive terms, suggesting that other classes of aroma compounds contribute to the vegetal aromas in wines. The results indicate a more complex interrelationship between chemical composition and sensory perception of vegetal aromas in Cabernet Sauvignon wines than had previously been hypothesized. Copyright © 2008 by the American Society for Enology and Viticulture. All rights reserved.
Article
Regulated deficit irrigation (RDI) and crop-load adjustment are regarded as important viticultural practices for premium-quality wine production, although little is known about their interactive effects. Crop loads were altered on field-grown, own-rooted Cabernet Sauvignon grapevines exposed to RDI varying in severity and timing in the arid Columbia Valley (Washington) from 1999 to 2003. Following a dry-down period through fruit set to stop shoot growth, vines were irrigated at 60 to 70% of full-vine evapotranspiration until harvest. Other vines either received the same amount of water up to veraison, after which the irrigation rate was cut in half, or had their irrigation halved before veraison but not thereafter. Clusters were thinned within irrigation treatments during the lag phase of berry growth to achieve a target yield of 6.7 t/ha, compared with an unthinned control. The severity and timing of RDI had only minor effects on vegetative growth, yield formation, fruit composition (soluble solids, titratable acidity, pH, K+, color), and cold hardiness. The more severe water-deficit treatments slowed berry growth while the treatments were being imposed, but final berry weights were similar in three of five years. Although cluster thinning reduced yields by 35% and crop loads by 32%, crop load had little or no influence on vegetative growth and cluster yield components and advanced fruit maturity at most by three to four days. Very few interactive effects of RDI and crop load were observed, indicating that the crop load did not influence the response of vines to RDI.
Article
Tannins are the most abundant class of phenolics in grape berries and are the predominant determinants of astringency in red wines. We have adapted a microtiter plate assay that was first described for persimmon tannin, so that it can be used for analysis of tannins in grapes and wines. Our modification incorporates a high salt wash step that is thought to remove non-specifically bound alkaline phosphatase enzyme that is used to detect tannin in the analysis. Application of the plate binding assay to fractions collected from a normal phase HPLC separation of seed tannins indicates that the assay only detects tannins having more than three flavan-3-ol subunits. The standard assay uses bovine serum albumin (BSA) as the protein bound to the microtiter plate, but we have found that casein or gelatin can be substituted for BSA in the assay. Results show that the microtiter plate assay can be used to monitor extraction of tannin from grape skins and seeds into a model wine solution. We have developed a new protein precipitation assay for grape and wine tannin that is based on the tannin's ability to co-precipitate alkaline phosphatase and BSA from a mixture of the two proteins. The tannin-protein precipitate is pelleted by centrifugation and washed to remove residual unprecipitated alkaline phosphatase. The tannin-protein complex is then dissolved in a 1 M diethanolamine buffer pH 9.4 and the amount of alkaline phosphatase activity in the dissociated precipitate is determined by addition of p-nitrophenylphosphate substrate. The amount of alkaline phosphatase activity in the redissolved pellet was shown to be proportional to the amount of seed tannin used to form the precipitate. Because the solution assay is easy to perform and requires only a spectrophotometer, it should be suitable for use even in small winery laboratories.
Article
Regulated deficit irrigation (RDI) and crop-load adjustment are regarded as important viticultural practices for premium-quality wine production, although little is known about their interactive effects. Crop loads were altered on field-grown, own-rooted Cabernet Sauvignon grapevines exposed to RDI varying in severity and timing in the arid Columbia Valley (Washington) from 1999 to 2003. Following a dry-down period through fruit set to stop shoot growth, vines were irrigated at 60 to 70% of full-vine evapotranspiration until harvest. Other vines either received the same amount of water up to veraison, after which the irrigation rate was cut in half, or had their irrigation halved before veraison but not thereafter. Clusters were thinned within irrigation treatments during the lag phase of berry growth to achieve a target yield of 6.7 t/ha, compared with an unthinned control. The severity and timing of RDI had only minor effects on vegetative growth, yield formation, fruit composition (soluble solids, titratable acidity, pH, K+, color), and cold hardiness. The more severe water-deficit treatments slowed berry growth while the treatments were being imposed, but final berry weights were similar in three of five years. Although cluster thinning reduced yields by 35% and crop loads by 32%, crop load had little or no influence on vegetative growth and cluster yield components and advanced fruit maturity at most by three to four days. Very few interactive effects of RDI and crop load were observed, indicating that the crop load did not influence the response of vines to RDI.
Article
The effect of climatic region, degree of ripeness, sunlight and shade on carotenoid concentrations in Weisser Riesling and Chenin blanc grapes was investigated. Lutein and beta-carotene concentrations were higher in grapes from hot regions than grapes from cooler regions. In general, decreases in carotenoid concentrations were observed with an increase in ripeness. Also, grapes exposed to sunlight generally had lower carotenoid concentrations than shaded grapes. Both lutein and beta-carotene concentrations varied little between Weisser Riesling and Chenin blanc grapes at comparable ripening stages.
Article
The fruiting capacity of grapevines in a given climatic region is largely determined by their total leaf area and by the percentage of the total leaf surface area that is exposed to full sunlight, provided other factors are not limiting growth and the initiation of fruit primordia. A wide range of leaf area/crop weight ratios were investigated by pruning to different levels of buds per vine, by different degrees of defoliation, and/or by cluster thinning of grape cultivars Thompson Seedless, Tokay, Chenin blanc, and Cabernet Sauvignon located at Davis or Oakville, California. For single-canopy (SC) type trellis-training systems, the leaf area/crop weight ratio required for maximum level of total soluble solids, berry weight, and berry coloration at harvest ranged from 0.8 to 1.2 m2/kg, whereas for horizontally divided-canopy (DC) type trellis-training systems (GDC, lyre, wye), this ratio was reduced to 0.5 to 0.8 m2 leaf area per kg fruit. Optimal crop yield/pruning weight, pruning weight (kg) per m canopy length, leaf area (m2) per m canopy length, and leaf area density (m2/m3) for SC systems ranged from 4.0 to 10, 0.5 to 1.0 kg/m, 2 to 5 m2/m, and 3 to 7 m2m−3, respectively. Similarly, for DC systems these ratios ranged from 5.0 to 10, 0.4 to 0.8 kg/m, 2 to 4 m2/m, and 3 to 6 m2m−3, respectively. Grapevines with ratios that fell within the ranges given above for each of these five parameters were considered well balanced and capable of producing high-quality fruit and wines.
Chapter
Norisoprenoids are volatile secondary metabolites which are important aroma constituents of a number of grape and wine varieties. The norisoprenoids are thought to arise from carotenoid breakdown and occur in grapes as glycosidically bound precursors. However, the factors which influence carotenoid breakdown and norisoprenoid formation in grapes are not well understood. In this study we evaluated the effect of seven levels of sunlight exposure (4%, 18%, 31%, 37%, 50%, 71%, and 97% expressed as percent of full sun exposure) on norisoprenoid concentrations in White Riesling. Our results suggest that viticultural practices which affect fruit exposure to sunlight may influence norisoprenoid composition of grapes and wines. In White Riesling, TDN (1,1,6-trimethyl-1,2-dihydronaphthalene) and Riesling acetal (2,2,6,8-tetramethyl-7,11-dioxatricycloundec-4-ene) levels increased at sunlight exposures above 20% of full sun exposure. Changes in grape berry temperature with increasing sunlight exposure may also have an influence on norisoprenoid levels.
Article
The interactive effects of mechanical canopy management on the optimum cropping level and Ravaz index of Pinot gris in a warm growing region were determined. The study examined two pruning methods, three shoot thinning treatments, and two leaf removal treatments arranged factorially in a randomized complete block design with four replications. The pruning methods were applied by either hand pruning to 23 nodes/m or mechanically hedging and retaining a 100 mm spur height. The shoot thinning treatments were applied mechanically at modified E-L stage 17 to retain 23 (low), 33 (medium), or 45 (high, not thinned) shoots/m of row. The leaf removal treatments removed leaves on the east side of the canopy in a 450 mm zone in the fruiting zone, 20 days postbloom with a mechanical deleafer or no leaf removal was done. The interaction of mechanical hedging and medium shoot thinning treatments reduced the contribution of noncount shoots to total shoots. Percent canopy gaps and photosynthetically active radiation increased, while canopy leaf layers decreased with the application of leaf removal regardless of pruning or shoot thinning regime in both years. Yield increased and berry and cluster weight decreased in both years with the application of mechanical hedging and medium shoot thinning compared to hand-pruned vines without any detrimental effects on fruit composition. To achieve the economic crop level threshold of 8.15 kg/m, a Ravaz index of 10.2 to 12.0 kg/kg was needed. This Ravaz index corresponded to a pruning weight of 0.82 to 0.92 kg/m. The study identified a mechanical hedging and shoot thinning method where a 100 mm spur height was retained during the dormant season and 35 shoots/m of row was retained at E-L stage 17 to optimize crop load without adversely affecting pruning weight or fruit composition in a warm climate. The identified method provided 79% labor operations cost savings compared to hand pruning alone.
Article
A production trial in the San Joaquin Valley of California was conducted where canopy microclimate of Syrah 05/SO4 grapevines was altered through three pruning systems and two leaf removal treatments arranged factorially to rejuvenate vineyards with declining productivity. Vines were either pruned by hand to 44 nodes each, mechanically box-pruned to a 10 cm hedge, or cane-pruned by hand to six 8-node canes arranged in opposing directions of the row with horizontal canopy separation. Outer surface layer of leaves were either removed mechanically 20 days postbloom on the east side of the canopy in a 45 cm zone above the cordon in the fruit zone or not removed. Yields from spur-and mechanically box-pruned vines were considered too low for the study area, and leaf removal had no effect on yield components. Spur-pruned vines reached 24 Brix earlier than mechanically box-pruned and cane-pruned vines in each year. Leaf removal had no effect on fruit composition of Syrah at harvest. Berry skin phenolics were not consistently affected by treatments applied. Cane pruning resulted in 3.8 leaf layers, with 32 shoots per 30 cm of row, 7.77 kg/kg Ravaz index, and consistently ripened 22 tons/ha to 24 Brix and should therefore be used in the San Joaquin Valley to improve yields in vineyards with declining productivity. The study identified a pruning system for vineyards in warm climates that can sustain yields and provides management information for growers on how to rejuvenate vines that have declined in productivity.
Article
UV-B radiation and water deficit may trigger flavonol and anthocyanin biosynthesis in plant tissues. In addition, previous research has showed strong qualitative effects on grape berry skin flavonol and anthocyanin profiles in response to UV-B and water deficit. The aim of this study is to identify the mechanisms leading to quantitative and qualitative changes in flavonol and anthocyanin profiles, in response to separate and combined UV-B and water deficit. Grapevines (Vitis vinifera L. cv. Tempranillo) were exposed to three levels of UV-B radiation (0, 5.98 and 9.66 kJ m−2 day−1) and subjected to two water regimes. A strong effect of UV-B on flavonol and anthocyanin biosynthesis was found, resulting in an increased anthocyanin concentration and a change in their profile. Concomitantly, two key biosynthetic genes (FLS1 and UFGT) were up-regulated by UV-B, leading to increased flavonol and anthocyanin skin concentration. Changes in flavonol and anthocyanin composition were explained to a large extend by transcript levels of F3′H, F3′5′H and OMT2. A significant interaction between UV-B and water deficit was found in the relative abundance of 3′4′ and 3′4′5′ substituted flavonols, but not in their anthocyanin homologues. The ratio between 3′4′5′ and 3′4′ substituted flavonols was linearly related to the ratios of F3′5′H and FLS1 transcription, two steps up-regulated independently by water deficit and UV-B radiation, respectively. Our results indicate that changes in flavonol profiles in response to environmental conditions are not only a consequence of changes in the expression of flavonoid hydroxylases; but also the result of the competition of FLS, F3′5′H and F3′H enzymes for the same flavonol substrates.
Article
Background and AimsPrevious studies have highlighted the importance of vineyard variability and the benefits that may accrue through targeting management in response to it. In this study, we were interested to see whether the concentration of rotundone in Shiraz (Vitis vinifera L.) grapes was spatially structured and related to other aspects of vineyard variability so as to inform the possible selective harvesting of grapes destined for wines of ‘peppery’ character.Methods and ResultsImmediately prior to harvest of a 6.1-ha block in the Grampians region of Victoria, a region known for producing wines of ‘peppery’ character, fruit was sampled from 177 ‘target vines’ and analysed for its rotundone concentration. The resulting data were mapped and overlain with other map layers describing variation in soils, topography and vine vigour. Berry rotundone concentration was found to be markedly spatially variable. The results further suggest that within-vineyard variation in berry rotundone concentration is associated with variation in soil properties and topography, with the influence of the latter on ambient temperature implicated as a likely key driver of rotundone variation.Conclusions Consistent with previous analyses of variability in indices of fruit quality, variation in berry rotundone concentration was found to be spatially structured; that is, its variation was not random. As with these previous studies, variation in berry rotundone concentration was associated with variation in the land underlying the vineyard.Significance of the StudyTo our knowledge, this is the first study of within-vineyard spatial variability in a grape-derived flavour compound. It highlights the potential opportunity, with further understanding of rotundone biosynthesis, to use selective harvesting and/or viticultural manipulation as a means of influencing wine style – in this case the ‘pepperiness’ of Shiraz.
Article
Quantitative data on the concentration of phenolic compounds in a large, representative sample of widely consumed commercial red wines have been lacking. The 21 highest volume Cabernet Sauvignon wines, representing 17% of all red wines sold in US supermarkets (and over two million 9-L cases), were selected based on 1995 WINESCAN data reports. The wines were analyzed using a HPLC method with a ternary solvent system to achieve separation of all monomeric phenols and anthocyanins, and the total phenolic content by Folin-Ciocalteau reagent was determined. The levels of each compound were then averaged using a weighting factor determined by each wine's representative volume to create a weighted average. These results were then compared to five ultra-premium (UP), commercially available Cabernet Sauvignons noted for their aging potential; the UP wines had significantly higher phenolic levels. The wines were also analyzed for their pH, titratable acidity, volatile acidity, free and total sulfur dioxide, alcohol, malic acid, glucose, and fructose using standard methods. Based on this data analysis, a standard Cabernet Sauvignon wine with typical phenolic levels is proposed.
Article
The effects of sunlight exposure on the berry growth and composition of two red wine grape cultivars grown in the central San Joaquin Valley of California (Region V) were examined. Field grown Cabernet Sauvignon and Grenache grape clusters were grown over a range of sunlight exposures (mid-day PAR <10 μmol m-2 sec-1 [shaded] to >600 μmol m-2 sec-1 [fully exposed]) from berry set to harvest. Both cultivars were planted in east-west oriented rows, and experimental clusters were evenly distributed between the north (afternoon shaded) and south (afternoon exposed) sides of the canopy. Fruit response to sunlight varied based on cluster location within the canopy, and these results were at least partially due to measured differences in berry temperature. At the same exposure level or PAR (photosynthetically active radiation), mid-day berry temperature was generally 3 to 4°C greater for clusters on the south side of the canopy compared to clusters on the north. Soluble solids initially increased with greater sunlight exposure, then declined when mid-day PAR exceeded 31 to 50 and 51 to 100 μmol m-2 sec-1, respectively, for clusters on the north and south sides of the canopy. Titratable acidity generally declined as sunlight exposure increased, with Cabernet Sauvignon clusters on the north side of the canopy maintaining greater acidity at the same exposure level than clusters on the south. Juice pH declined as exposure increased on the north side of the canopy, while sunlight had little effect on juice pH for clusters on the south. Anthocyanins increased linearly as sunlight exposure on the north side of the canopy increased, but declined when cluster exposure on the south exceeded 100μmol m-2 sec-1. Total phenolics generally followed a similar pattern. The results suggest that the effects of light on fruit composition are heavily dependent upon the extent to which berry temperature is elevated as a result of increased sunlight exposure. Prolonged exposure of clusters to direct sunlight should be avoided for maximum berry color in the central San Joaquin Valley and other warm regions.
Article
The hydrolysis, in model wine at pH 3, of the allylic, homoallylic, and propargylic glycosides, geranyl-beta-D-glucopyranoside, [3'-(1 "-cyclohexenyl)-1'-methyl-2'-propynyl]-beta-D-glucopyranoside, (3'RS,9'SR)-(3'-hydroxy-5'-megastigmen-7-yn-9-yl)-beta-D-glucopyranoside, (3',5',5'-trimethyl-3'-cyclohexenyl)-beta-D-glucopyranoside, E-(7'-oxo-5',8'-megastigmadien-3'-yl)-beta-(3-hydroxy-beta-damascone-beta-D-glucopyranoside), and their corresponding aglycons has been studied. In general, aglycons were more rapidly converted to transformation products than were the corresponding glucosides. Glycoconjugation of geraniol in grapes is a process that reduces the flavor impact of this compound in wine, not only because geraniol is an important flavor component of some wines but also because the rate of formation of other flavor compounds from geraniol during bottle-aging is reduced. However, when flavor compounds such as beta-damascenone are formed in competition with flavorless byproducts, such as 3-hydroxy-beta-damascone, by acid-catalyzed hydrolytic reactions of polyols, then glycoconjugation is a process that could enhance as well as suppress the formation of flavor, depending on the position of glycosylation. (3'RS,9'SR)-(3'-Hydroxy-5'-megastigmen-7'-yn-9'-yl)-beta-D-glucopyranoside hydrolyzed more slowly but gave a higher proportion of beta-damascenone in the products than did the aglycon at 50 degrees C. Reaction temperature also effected the relative proportion of the hydrolysis products. Accelerated studies do not parallel natural processes precisely but only approximate them.
Article
Grape berries of Vitis vinifera L. cv. Baga were collected during 7 weeks since half-véraison to a post-maturation stage. Two vineyards in different locations in Bairrada Appellation, Pedralvites (Ped) and Colégio (Col) were used. The free varietal and pre-fermentative related volatile compounds that arise in the first 2h after crushing the grapes were followed by Headspace-Solid Phase Microextraction (HS-SPME). Twenty-three sesquiterpenoids, 13 monoterpenoids, 6 norisoprenoids, 2 aromatic alcohols, and 1 diterpenoid were detected in both vineyards. However, 40 sesquiterpenoids and 10 norisoprenoids were detected in Ped. The maximum gas chromatographic peak area was reached at the maturity, and remained constant until post-maturation. At maturity sesquiterpenoids represented 56% and 80% of the total varietal GC peak area in Col and Ped, respectively, which was the group with higher number of constituent varietal compounds. The results obtained indicated a high number of sesquiterpenoid compounds, namely (+)-cycloisosativene, γ-elemene, α-ylangene, β-bourbonene, β-cubenene, β-caryophyllene, 3,7-guaiadiene, (−)-isoledene, (+)-aromadendrene, α-amorphene, (−)-δ-selinene, germacrene D, epizonarene, β-cadinene, γ-cadinene, δ-cadinene, α-muurolene, α-calacorene in ‘Baga’ ripe grapes, which allows to suggest that this variety is a potential source of sesquiterpenoids.
Article
Seasonal water use of Vitis vinifera L. (cv. Thompson Seedless, clone 2A) was determined with a large weighing lysimeter in the San Joaquin Valley of California from 1994 to 1996. The first year of the study, the vines growing within the lysimeter were treated as would be done to produce fruit for use as table grapes; the application of gibberellic acid (GA3) and trunk girdling at berry set (approximately 2 weeks after anthesis). Both practices will increase berry size of this seedless cultivar. In 1995, the vines in the lysimeter were only girdled at berry set, no application of GA3 at that time. Reference crop evapotranspiration (ETo) between March 15th and the end of October averaged 1124mm across the 3 years. Water use shortly after the vines were girdled in 1994 increased as would be expected for non-girdled grapevines while in 1995 water use after girdling decreased for a period of approximately 4 weeks. Once the girdles healed (callused over) in 1995 water use increased to values similar to those of the previous year. The crop coefficient (Kc) subsequent to girdling in 1994 remained constant for a period of 4 weeks while the Kc decreased after girdling in 1995. The Kc increased after the girdles healed both years and remained at a value of approximately 0.9 until the end of October. In 1996, the vines in the lysimeter received none of the treatments used the previous 2 years. The seasonal water use and maximum daily water use in 1996 of the vines in the lysimeter were greater than in 1994 and 1995. Water use of the vines was equivalent to 838, 708 and 936mm from March 15 until the end of October while that of ETo was 1136, 1060, and 1176 during the same period in 1994, 1995 and 1996, respectively. At full canopy in 1996 the Kc leveled off at a value of 1.1 and remained such until the end of October. The results indicate that girdling the trunks of grapevines can affect water use when compared to non-girdled grapevines. Additionally, the Kc of this perennial horticultural crop does not decrease after harvest or later in the season if the vines are fully irrigated and insect pests are controlled.
Article
Background and Aims:  While shoot thinning is one of the most widely applied practices in the vineyard as a tool to regulate canopy density and/or crop level, its physiological bases are still fairly obscure and have been poorly investigated. Our aim was to assess seasonal modification of whole-canopy net CO2 exchange rate (NCER) in thinned and non-thinned grapevines, as well as establishing correlations with grape composition.Methods and Results:  Potted, mature cv. Barbera vines were thinned (ST) to 10–15 shoots/m over the two trial years and compared with a non-thinned control (C). The data logged each season included whole-vine NCER monitored pre- and post-veraison for periods of variable lengths, vine growth, yield components and grape composition. While final leaf area per vine did not differ between treatments, ST showed reduced yield and improved berry colour and must sugar accumulation. In 2009, NCER/vine recovery in ST was 85% of C at verasion, whereas in 2010 full recovery was already reached around bloom.Conclusions:  A load of 15 shoots/m maximised canopy efficiency by inducing the fastest recovery of whole-vine photosynthesis and markedly improved sugar, colour and phenolics. Retaining 10 shoots/m delayed NCER recovery while improving overall grape composition as compared to C.Significance of the Study:  Direct assessment of the complex seasonal canopy NCER dynamics triggered by shoot thinning indicates that the source-sink balance evolves in ST towards a higher supply of assimilates per unit of crop than that available in non-thinned canopies during the veraison-to-harvest period.
Article
The detailed crop specific descriptions of the phenological growth stages of grapevine are supplementary to the general BBCH-scale. It will be instrumental in standardising the national and international experimentation in viticulture. The phenological development of the grapevine is divided into growth phases (principal growth stages 0–9) and each growth phase is subdivided into growth steps (secondary growth stages 0–9). A two-digit code is attached to each growth stage. The description and coding of the phenological growth stages covers the period between dormancy and leaf fall.
Article
The dependence of wine quality on the irrigation management strategies in Vitis vinifera L. was tested from 1999 to 2002. A drip-irrigation experiment was performed on white grapes of the cultivars Baladí, Airén, Montepila, Muscat Blanc à Petits Grains and Pedro Ximénez, grafted and vineyard-planted in 1995 in Cabra (Cordoba, Spain). Treatments consisted of a nonirrigated control and an experimental deficit irrigation, in which water was applied from fruit set until near harvest. A total of 19 analytical parameters were measured, including alcohols, total phenol content and optical density as well as ethanol, pH, total acidity and dry extract. Wines were evaluated for their visual characteristics, aroma, taste and finish. The irrigation treatment contributed to a higher dry extract, and an increase in malic acid and potassium in wines. There was a decrease in pH, isobutanol and isoamyl alcohols with increasing water application. Sensory evaluation ranked irrigated over nonirrigated wines with the only exception of the wines of Muscat Blanc à Petits Grains. The main defects of nonirrigated wines were attributed to visual characteristics and poorer taste quality.
Article
The dependence of wine sensory properties on vine water status in Vitis vinifera L., cv. Cabernet Sauvignon was tested. Cabernet Sauvignon vines in the Napa Valley were subjected to three drip irrigation treatments: minimal irrigation (no irrigation added unless the midday leaf water potential dropped below –1.6 MPa), standard irrigation (32 L water/vine/week), and double irrigation (64 L water/vine/week). The minimal irrigation treatment produced midday leaf water potentials that were significantly lower than the other treatments throughout the season. Mean grape yields varied from 15.0 to 21.7 t/ha. Descriptive analysis conducted on the resulting wines demonstrated significant differences in several sensory attributes as per analysis of variance of the ratings. Analysis of variance and principal component analysis showed that the wines made from the minimal irrigation treatment were significantly higher in red/blackberry aroma, jam/cooked berry aroma, dried fruit/raisin aroma, and fruit by mouth than the wines from the irrigated treatments. The standard irrigation treatment wines were rated significantly higher than the minimal irrigation treatment wines in vegetal aroma, bell pepper aroma, black pepper aroma, and astringency. We conclude that vine water deficits lead to wines with more fruity and less vegetal aromas and flavours than vines with high vine water status.
Article
An Aroma Extract Dilution Analysis (AEDA) has been carried out on three monovarietal young red wines plus a mixture of wines aged one year. The aromograms contain 85 odour-active regions classified in four categories of intensity. The 11 most powerful odorants, 14 out of the 17 second-most powerful, and 34 of the rest could be identified using a HPLC prefractionation method and standard HRGC-MS-olfactometric techniques. The most active odorants of the monovarietal wines were isoamyl and β-phenylethyl alcohols, the ethyl esters of butyric, isobutyric, 2-methyl butyric and hexanoic acids, γ-nonalactone and eugenol. Some others worth mentioning are ethyl isovalerate, isoamyl acetate, hexanol, c-3-hexenol, linalool, geraniol, guaiacol, ethyl cinnamate, ethyl dihydrocinnamate, β-damascenone, δ-decalactone and wine lactone. Compounds with less aromatic intensity but also present in some of the wines were sotolon, isopropyl- and isobutylmethoxypyrazines and 4-mercapto-4-methylpentan-2-one. Data show that there are no impact compounds characteristic of only one variety, and that differences between varieties are quantitative rather than qualitative.© 1999 Society of Chemical Industry
Article
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
Article
Solid-phase microextraction using a 100 µm poly(dimethylsiloxane) fiber, followed by gas chromatography–mass spectrometry determination, has been optimized for the analysis of some terpenes in wine samples. The best results were obtained by direct immersion of the fiber using a sampling period of 15 min with constant magnetic stirring (1100 rpm) and an extraction temperature of 20 °C. The sample volume was 7 ml with 25% NaCl, in a 15 ml capped vial. Desorption was performed directly in the gas chromatograph injector port over 5 min at 250 °C using the splitless mode. The method is sensitive, with detection limits between 11 and 25 µg l−1, precise, with variation coefficients in the range 1.28–3.71%, and linear over more than one order of magnitude. The related conditions were used for wine sample analyses with recoveries between 71.8 and 90.9%. Solid-phase microextraction remains an attractive alternative technique due to its rapidity and because it is a solvent-free extraction. Copyright © 2005 Society of Chemical Industry