Hydrolytically-released volatile secondary metabolites from a juice sample of Vitis vinifera grape cvs Merlot and Cabernet Sauvignon

The volatile components of a Merlot and a Cabernet Sauvignon juice, as well as the volatile compounds released by acid- or glycosidase enzyme hydrolysis of C18 reverse phase isolates of the juices, have been analysed. The categories of constituents (i.e. monoterpenes, benzenoid compounds, norisoprenoids, aliphatic and miscellaneous compounds) and the components observed within these categories were broadly similar to those previously reported for other varieties. The potent flavour compound, damascenone, was a major component of the acid hydrolysates of both juice samples. The damascenone precursor trans-megastigma-6,7-diene-3,5,9-triol was identified as a hydrolysis product of grape-derived C18 reverse phase isolates for the first time.     

新疆琐琐葡萄和赤霞珠葡萄的酿酒研究

研究了新疆琐琐葡萄和赤霞珠葡萄在发酵过程中还原糖、总酸、酒精度、色度的变化情况,并通过感官评价和理化指标分析得出:琐琐葡萄和赤霞珠葡萄的酒精发酵过程基本一致,酒精度分别为9.2%vol和9.8%vol,残糖分别为2.5g/L和1.7g/L:琐琐葡萄酒的总酸和色度均低于赤霞珠葡萄酒,总酸分别为4.29g/L和7.67g/L,色度分别为0.498和0.687:琐琐葡萄酒色浅口感柔和,赤霞珠葡萄酒色泽优美、酒体丰满.     

Do temperature conditions at budburst affect flower number in Vitis vinifera L. cv. Cabernet Sauvignon?

Timing of winter pruning (early July versus mid‐August) and the application of hydrogen cyanamide were used to manipulate the time of budburst in a population of spur‐pruned, 13‐year‐old Vitis vinifera L. Cabernet Sauvignon vines grown in central Victoria. Delaying pruning by six weeks delayed budburst by an average of four days. This extended the duration of budburst for the entire population, thus, exposing bursting shoots to a greater range of temperature conditions. Flowers per inflorescence and bunches per shoot were estimated by destructively sampling 300 inflorescences prior to anthesis from shoots of known bursting date. Pruning time did not significantly affect flowers per inflorescence. However, across the entire population of inflorescences sampled, flowers per inflorescence was weakly correlated with daily maximum air temperature on the day of budburst, daily mean soil temperature on the day of budburst and date of budburst (P < 0.001, Adjusted R²= 3.6%, 3.7%, 4.5% respectively). Inflorescences had fewer flowers on later‐bursting shoots and also as temperatures on the day of budburst increased. More of the variance in flowers per inflorescence was accounted for by the number of inflorescences on the shoot (P < 0.001, Adj. R²= 17.4%) and the position of the inflorescence relative to other inflorescences on the same shoot, i.e. lower of two, upper of two or sole (P < 0.001, Adj. R²= 26.1%). Average flowers per inflorescence declined in the order lower of two > upper of two > sole. The best regression model included the position of the inflorescence relative to other inflorescences on the shoot and the date of budburst (P < 0.001), but this still accounted for only 29.2% of the total variance in flowers per inflorescence. Mean flowers per inflorescence was significantly (P < 0.05) and substantially (97% for back‐transformed means) higher for inflorescences on two‐inflorescence shoots than for inflorescences on single inflorescence shoots. This suggests that conditions during the previous spring that favour the initiation of uncommitted inflorescence primordia (i.e. high temperature and adequate light) also precondition inflorescences to higher flower numbers.     

Biomass distribution and nitrate assimilation in response to N supply for Vitis vinifera L. cv. Cabernet Sauvignon on five Vitis rootstock genotypes

Effects of nitrogen (N) supply on biomass distribution as well as N effects on NO₃"assimilation, were examined in two-year-old graftlings of Vitis vinifera L. cv. Cabernet Sauvignon on five rootstocks. Whole-plant biomass in all graftlings more than doubled with increased N supply in solution from 0.25 to 8 mM. Whole plant biomass was also affected by rootstock genotype, but to a lesser extent than by N supply. Biomass allocation to roots declined with increased N supply for all stock-scion combinations, but the magnitude of that response varied with rootstock genotype. Nitrate reductase activity (NRA) in leaves increased with increased N supply for all stock-scion combinations, whereas root NRA increased only up to 1 mM N supply, dropping markedly with additional N. NRA in leaves was one to two orders of magnitude higher than NRA in roots - a difference that increased steadily with increased N supply. By implication, grapevine leaves have a much higher capacity for NO₃^-_- reduction than do grapevine roots, and any contribution by roots to whole-vine NO₃^-_- assimilation declines even further as NO₃^-_- availability increases.     

Antioxidant activity in relation to the phenolic profile during the winemaking of sweet wines Vitis vinifera cv. Cabernet Sauvignon

The phenolic profile during the winemaking of Cabernet Sauvignon sweet wines has been studied, including the stages of controlled grape drying and the posterior maceration of the fortified musts with their skins. Each phenolic family has been correlated individually with the antioxidant activity measured by the 2,2,‐diphenylpicrylhydrazyl assay. Linear regressions with a confidence level superior to 99% have been found with hydroxybenzoic acids, esters of hydroxycinnamic acids, flavan‐3‐ol derivatives, tannins, anthocyanin adducts, polymers and polymeric pigments. With a multiple correlation, the antioxidant properties of musts and sweet wines were explained jointly by the families of polymeric pigments and flavan‐3‐ol derivatives. The musts during the drying process and the wines during the maceration presented a different phenolic composition and were distinguished using a cluster analysis and a principal component analysis.     

赤霞珠葡萄生长发育过程中内源激素的变化及其与果实成熟的关系

为研究赤霞珠葡萄果实发育过程中不同组织(果皮、果肉和种子)内源激素的含量变化及其与果实成熟的关系,用高效液相色谱-质谱联用技术测定果实发育过程中果皮、果肉以及种子中脱落酸(abscisic acid,ABA)、生长素(indole acetic acid,IAA)、赤霉素(gibberellin A_3,GA_3)、茉莉酸(jasmonic acid,JA)和水杨酸(salicylic acid,SA)的含量。结果发现,在葡萄果实生长发育过程中,葡萄果皮和果皮中ABA含量呈双S型变化,花后20 d左右,ABA含量较高,随着果实膨大开始下降,随后开始上升,至转色中期达到最大值,随着果实的成熟缓慢下降;果皮、果肉和种子中GA_3含量均是从果实膨大期开始上升,膨大后期下降,随后在转色初期又开始上升,随后下降;JA含量的变化与GA_3类似;果皮和果肉中IAA含量首先略微下降,在果实快速生长期迅速上升,并达到峰值,随着果实进入转色期,含量逐渐下降并保持稳定,果实膨大期之前,种子中IAA含量较高,随着果实膨大降低,并维持在较低水平,SA含量的变化与IAA类似。结论:ABA、GA_3、JA含量与赤霞珠果实成熟有关,IAA、GA_3、SA、JA含量与赤霞珠果实生长有关。     

Growth, photosynthesis and cropping of potted grapevines (Vitis vinifera L. cv. Cabernet Sauvignon) in relation to shoot trimming

The present study was conducted to evaluate how changes in leaf area affected vine growth, yield and grape quality of five‐year‐old potted Cabernet Sauvignon grapevines. At the beginning of flowering vines were randomly assigned to the following five treatments: untrimmed (control); shoot trimmed at either node 12 (T12) or node 6 (T6) with laterals either retained (R) or excised (X). Those four manipulations are abbreviated to: T12LR, T12LX, T6LR and T6LX, respectively. Total leaf area per vine was significantly lowered in T12LX and T6LX as compared to the other treatments, whereas lateral formation was able to offset foliage loss due to trimming in T12LR and T6LR with respect to control vines. T6LR also showed a more prolonged lateral node production. Yield per vine and its components did not differ significantly among treatments except for berry size, which was reduced in T6LR and T6LX. Grape ripening was severely retarded in T6LX, as shown by lower Brix, pH, colour and phenolics, and higher TA, tartrate and malate. A maturity delay was also shown in T6LR as lower soluble solids and total anthocyanins per berry in comparison with untrimmed vines. No difference in grape quality versus control was shown by the T12 treatments. Post‐trimming assimilation rates (A) clearly indicated a large compensation capacity of retained main leaves despite their mean age being higher than that calculated for main leaves sampled the same day on control vines. The assimilation rates recorded on lateral leaves increased proportionally with lateral shoot size and inversely to the number of main leaves retained with trimming. Based on present results, both the area and photosynthetic effectiveness of source leaves will drive overall vine responses to shoot trimming. For example, T6LX showed the worst performance with respect to the other treatments, in agreement with lowest leaf area, leaf‐to‐fruit ratio and oldest canopy. However, T6LR had a somewhat retarded ripening despite its non‐limiting leaf‐to‐fruit ratio, relatively young canopy and maximum whole‐canopy photosynthesis and efficiency at veraison. Under such circumstances, duration of growth and possible competition with the berry sugaring process may have played a role.     

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

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

Influence of partial rootzone drying on the composition and accumulation of anthocyanins in grape berries (Vitis vinifera cv. Cabernet Sauvignon)

Background and Aims: The aim of the study was to investigate anthocyanin composition and accumulation in grape berries in response to the partial rootzone drying (PRD) irrigation technique.
Method and Results: The experiment was on Vitis vinifera cv. Cabernet Sauvignon, wherein PRD had a 40% water deficit relative to the control treatment. PRD decreased berry weight compared with the control, but did not influence total anthocyanin concentration. A significant increase in glucosides of delphinidin, cyanidin, petunidin and peonidin was found in response to PRD from the onset of anthocyanin accumulation (veraison), while malvidin-glucosides were unaffected by the irrigation treatment. The PRD treatment did not cause changes in the proportions of acetyl-, 3- p -coumaroyl- and monoglucoside anthocyanins. Wines produced from the treatments showed no difference in total monomeric anthocyanin, but relative increases (15%) in wine colour density, total tannin and polymeric pigment occurred in response to the PRD treatment. The anthocyanin composition of the wines reflected the response shown in the grapes, where the relative contribution of non-malvidin anthocyanins to total anthocyanins was significantly increased in wines from the PRD treatment.
Conclusions: The differences in anthocyanin composition observed in response to PRD could not be accounted for by changes in bunch microclimate, and most likely reflect differences in the methylation step of anthocyanin synthesis.
Significance of the Study: The observed changes in anthocyanin composition under the PRD irrigation system have not been previously reported in response to water deficit, and may reflect a unique response to within-vine signalling induced by PRD.     

三种不同珠干红葡萄酒品质的对比性研究

选取烟台地区的赤霞珠、梅鹿辄和蛇龙珠葡萄为原料,采用相同的工艺酿造干红葡萄酒,对酒的品质进行对比研究。结果表明,酒中3-甲基-1-丁醇、2-甲基-1-丁醇、1-己醇、β-苯乙醇、4-羟基-苯乙醇、甘油、丁二酸单乙酯、1,4丁内酯和丁二酸二乙酯的含量为赤霞珠＞梅鹿辄＞蛇龙珠。赤霞珠、梅鹿辄葡萄酒中2-甲基-1-丙醇的含量均高于蛇龙珠葡萄酒。蛇龙珠葡萄酒中丙醇、1-丁醇、丁二醇的含量较高。蛇龙珠葡萄酒中乳酸含量最高,而梅鹿辄葡萄酒中酒石酸含量最高。梅鹿辄、赤霞珠葡萄酒中杨梅素、槲皮素含量分别为蛇龙珠葡萄酒的5.0倍、6.4倍和19.6倍、44.5倍。蛇龙珠葡萄酒中除对香豆酸外,其余酚类物质的含量较少。梅鹿辄和赤霞珠葡萄酒的感官得分高于蛇龙珠葡萄酒。     

A functional association in Vitis vinifera L. cv. Cabernet Sauvignon between the extent of primary branching and the number of flowers formed per inflorescence

The number of primary branches (those branches that arise directly from the rachis) and the total number of flowers were counted for inflorescences of Vitis vinifera L. cultivar Cabernet Sauvignon over a range of climates and a number of seasons as part of a yield prediction study. Regression analysis indicated that the number of primary branches per inflorescence exerted a strong control over the total number of flowers per inflorescence, with highly significant ( P < 0.01) relationships explaining between 51 and 80% of the variation in flowers per inflorescence. Because the extent of primary branching is largely determined prior to grapevine buds entering dormancy, this strong functional association between branching and flower numbers, suggests that season-to-season differences in potential inflorescence size will be greatly affected by conditions during that phase of primordial differentiation in the previous growing season. A general tendency for the number of flowers per inflorescence to be positively related to other measures of vine fertility, supports this view. Lower orders of branching (secondary and tertiary) down to formation of individual flowers at budburst, also have the potential to influence eventual inflorescence size. As to the timing of such influences, we noted that increased severity of winter pruning significantly increased both flowers per inflorescence (by 9%) and the number of primary branches per inflorescence (by 21%). Such responses provide strong support for our contention that although the extent of primary branching is largely determined prior to grapevine buds entering dormancy, differentiation of new primary branches in Cabernet Sauvignon inflorescences continues to occur after the onset of dormancy.     

Comparison of major volatile compounds from Riesling and Cabernet Sauvignon grapes (Vitis vinifera L.) from fruitset to harvest

Background and Aims: Research on concentration changes of volatile compounds during grape physiological development has focused on the period from veraison to harvest. This study compared the developmental changes in the major volatile compounds released after the crushing of Riesling and Cabernet Sauvignon grapes sampled from fruitset to harvest during the 2007–2008 season. Methods and Results: Volatile compounds were extracted from the headspace of crushed Riesling and Cabernet Sauvignon grapes sampled throughout berry development using solid-phase microextraction and analysed by gas chromatography–mass spectrometry. A multivariate statistical approach coupled with analysis of variance was applied to compare the developmental changes in volatile compounds for the two cultivars. In both cultivars, E-2-hexenal was the most abundant volatile compound, and it showed a significant increase in concentration after veraison. Benzene derivatives discriminated ripe Cabernet Sauvignon grapes, whereas monoterpenes and sesquiterpenes discriminated both cultivars pre-veraison with a broader range of terpenes observed in the Cabernet Sauvignon samples compared with the Riesling samples. At veraison, terpene production in both varieties was low, but Riesling grapes produced some terpenes (geraniol and α-muurolene) post-veraison. Generally, esters and aldehydes were the major class of compounds from Riesling grapes, while Cabernet Sauvignon showed a greater tendency to form alcohols. Conclusions: Both Riesling and Cabernet Sauvignon grapes had a more complex volatile compound composition pre-veraison than post-veraison. This study suggests that some compounds that contribute to grape aroma may be produced pre-veraison, and not simply accumulate after veraison. Significance of the Study: Understanding the timing of volatile compound production and cultivar differences will guide viticulture researchers and growers in the optimisation of vineyard strategies to enhance grape aroma attributes that may, in turn, contribute to wine aroma.     

避雨栽培对蛇龙珠果实及葡萄酒质量影响研究初报

研究避雨栽培对酿酒葡萄果实采收期、果实品质和葡萄酒质量的影响,为酿酒葡萄避雨栽培技术的实施提供理论依据.以蛇龙珠(Vitis vinifera L cv.Cabernet Gernischt)为材料,采用简单避雨方式和露地栽培(对照),在果实转色期后监测果实糖酸变化,并测定成熟果实还原糖、总酸、花色素、总酚和单宁等指标;采用小容器酿造工艺酿制蛇龙珠干红葡萄酒,测定葡萄酒的颜色、花色素、总酚和单宁等指标.结果表明:(1)避雨栽培推迟了蛇龙珠果实的成熟期;(2)避雨栽培对蛇龙珠果实花色素、葡萄果皮中单宁含量影响极显著,对其他指标没有显著影响;(3)避雨栽培对蛇龙珠干红葡萄酒花色素含量及颜色影响极显著,对总酚和单宁含量无显著影响.     

根域温度对‘赤霞珠’葡萄根系发生及植株水分的影响

以两年生盆栽‘赤霞珠’嫁接苗为试材,在休眠解除期对根系进行升温(14℃)和低温(0℃)处理,测定根系发生及植株水分含量变化。结果发现,根系升温处理显著提高根系底物水平和呼吸启动,增加新根数量,根尖总数比低温处理提高36.9%,根系总长度和根系总面积也分别比低温处理提高16.3%、20.8%。根系升温处理提高根系和枝条组织的含水量,且呈迅速升高趋势,而低温处理显著延缓根系和枝条组织含水量的升高,说明高温有利于激活根系底物和呼吸途径,促进新根生成,增强水分的吸收,降低枝条抽干的发生。     

“赤霞珠”葡萄转色后不同成熟度指标的变化

研究酿酒葡萄转色后不同成熟度指标的动态变化规律。以“赤霞珠”葡萄为试材,分别测定了技术成熟度和总酚成熟度指标,并进行了浆果感官评价。结果表明：转色后果实物理性状参数和糖含量迅速增加,转色后第4周达到最大值,成熟后期略有下降。果实中总花色苷含量逐渐增加,在转色后第6周达到最高,随后有所降低。浆果中可提取花色苷含量持续增加。细胞成熟指数、种子成熟指数和总酚指数总体上逐渐降低。果皮单宁含量变化较小,种子单宁含量在成熟前期显著降低（P＜0.05）,后期变化较小。不同分子大小聚合色素的含量逐渐增加,转色后第6周时达到最大值。浆果感官评价中各种成熟度的得分逐渐增加,果肉香气成熟度和果皮成熟度得分均在转色后第7周时最高,成熟后期变化较小。     

Environmental effects on cv Cabernet Sauvignon (Vitis vinifera L.) grown in Hawke's Bay, New Zealand.: 1. Phenology and characterisation of viticultural environments

Six Cabernet Sauvignon vineyard sites in Hawke's Bay (New Zealand), selected out of 28 sites observed in 1996/97, were studied over three consecutive seasons in order to characterise viticultural environments of this region for this cultivar. Indices of precocity of vine phenology were used to analyse the relationship between phenology at the selected sites and vegetative growth, productivity, fruit ripening and wine sensory characteristics. Marked differences in indices of precocity existed between sites. These differences were mostly correlated with vine vegetative growth and canopy indices. There was no relationship between yield and vine phenology. Indices of precocity were correlated with certain juice constituents measured on a common date, as well as the sensory scores of wines produced by microvinification from grapes harvested on different dates and maturity levels. Vineyard sites that differed in indices of precocity also differed in their environmental characteristics, particularly in soil physical properties and water balance.