Influence of grape-harvesting steps on varietal thiol aromas in Sauvignon blanc wines

The intense tropical fruit aroma of Sauvignon blanc wines has been associated with the varietal thiols 3-mercaptohexanol (3MH), derived from odorless precursors in the grape, and 3-mercaptohexyl acetate (3MHA), arising from 3MH during fermentation. Grapes and juice were sourced from five locations in Marlborough, New Zealand, taking hand-picked grapes and samples at four stages during the mechanical harvesting process and pressing, which were then fermented in replicated 750 mL bottles. With each set of juices, the highest concentrations of Cys-3MH and Glut-3MH were found in the juices pressed to 1 bar, but these juices produced wines with lower 3MH and 3MHA concentrations. With three of the juices, there was an increase in varietal thiol content for wines made from juices that had been machine harvested compared to the hand-picked samples, which matched earlier findings of lower 3MH and 3MHA levels in wines made from hand-picked grapes. Juices that were more oxidized, and which showed a higher absorbance at 420 nm, were found to produce wines with lower 3MH and 3MHA concentrations.     

Associations between the sensory attributes and volatile composition of Cabernet Sauvignon wines and the volatile composition of the grapes used for their production

The sensory properties of wine are influenced by the chemical composition of the grapes used to produce them. Identification of grape and wine chemical markers associated with the attributes perceived by the consumer of the wine will enable better prediction of the potential of a parcel of grapes to produce wine of a certain flavor. This study explores the relationships between Cabernet Sauvignon grape volatile composition and wine volatile profiles with the sensory properties of wines. Twenty grape samples were obtained from nine vineyard sites across three vintages and wines vinified from these parcels using controlled winemaking methods. The volatile composition of the grapes were analyzed by SBSE-GCMS, the wines were analyzed by SPME-GCMS, and these data sets were compared to that obtained from the sensory analysis of the wines. Statistical treatment of the data to account for vintage and region effects allowed underlying relationships to be seen between wine sensory attributes and wine or grape volatile components. The observed associations between grape or wine volatile compounds and wine sensory attributes has revealed target compounds and pathways whose levels may reflect the biochemical effects on grape composition by differing growth conditions during berry development and ripening. The compounds identified in this study may be useful grape or wine markers for potential wine sensory characteristics.     

天津地区赤霞珠和梅鹿辄葡萄浆果发育特点和采收期的确定

研究赤霞珠和梅鹿辄葡萄浆果的生长发育过程中形态指标和生理指标结果表明两个葡萄品种浆果的生长动态为双S曲线;在浆果成熟期,含糖量和含酸量的变化与浆果生长发育进程、降雨、温度等有关;接近采收期,含糖量仍持续增长,而含酸量变化相对较小;采收期应根据浆果含糖量、气候变化、含酸量以及果粒形态变化等指标来决定,采前浆果理化指标的测定应在浆果生长转折点出现后进行,并以转折点作为始点.     

Vitisin A content in Chilean wines from Vitis vinifera Cv. Cabernet Sauvignon and contribution to the color of aged red wines

Vitisin A was prepared from malvidin 3-glucoside and pyruvic acid in model wine medium, isolated by countercurrent chromatography, and purified by preparative high-performance liquid chromatography (HPLC). The synthesized compound was used as a reference standard to quantify vitisin A in Chilean wines from Vitis vinifera cv. Cabernet Sauvignon, including a vertical row of wines from the same vineyard over 16 years. Maximum vitisin A content was reached within the first year of storage. Importantly, up to half of the initial amount of vitisin A in young wines was still present in 15 year old wines. Although vitisin A was found to be much more stable as compared to other monomeric C-4 underivatized anthocyanins, it also slowly degrades after reaching its peak concentration. The "color activity concept" was applied to vitisin A, malvidin 3-glucoside, malvidin 3-(6' '-acetylglucoside), and polymeric pigments isolated by countercurrent chromatography in order to estimate their contribution toward the overall color expression of wines. It was found that vitisin A is only a minor contributor to the visually perceived color of aged red wines (color contribution approximately 5%). The major contributor is the polymeric fraction (color contribution approximately 70-90%).     

Effect of oxygen on volatile and sensory characteristics of Cabernet Sauvignon during secondary shelf life

The oxidation of Cabernet Sauvignon wines during secondary shelf life was studied by headspace solid-phase microextraction (HS-SPME) coupled to gas chromatography-quadrupole mass spectrometry (GC-qMS) and sensory tests, with the support of multivariate statistical analyses such as OPLS-DA loading plot and PCA score plot. Four different oxidation conditions were established during a 1-week secondary shelf life. Samples collected on a regular basis were analyzed to determine the changes of volatile chemicals, with sensory characteristics evaluated through pattern recognition models. During secondary shelf life the separation among collected samples depended on the degree of oxidation in wine. Isoamyl acetate, ethyl decanoate, nonanoic acid, n-decanoic acid, undecanoic acid, 2-furancarboxylic acid, dodecanoic acid, and phenylacetaldehyde were determined to be associated with the oxidation of the wine. PCA sensory evaluation revealed that least oxidized wine and fresh wine was well-separated from more oxidized wines, demonstrating that sensory characteristics of less oxidized wines tend toward "fruity", "citrous", and "sweetness", while those of more oxidized wines are positively correlated with "animal", "bitterness", and "dairy". The study also demonstrates that OPLS-DA and PCA are very useful statistical tools for the understanding of wine oxidation.     

A survey of seasonal temperatures and vineyard altitude influences on 2-methoxy-3-isobutylpyrazine, C13-norisoprenoids, and the sensory profile of Brazilian Cabernet Sauvignon wines

This report has investigated the seasonal temperatures influences (winter and summer) of five vineyards at different altitudes on the concentrations of 2-methoxy-3-isobutylpyrazine (MIBP), alpha- and beta-ionone, and beta-damascenone in 2004 or 2005 vintages of Cabernet Sauvignon wines from Santa Catarina State, Brazil. Sensorial analyses were also carried out on the wine samples and compared to altitude and climate. Significant regression was observed between MIBP concentrations and the vineyard's altitude. No significant relation was observed between alpha- and beta-ionone and beta-damascenone with the vineyard's altitude. Principal component analysis positively correlated wines from higher altitudes with a "bell pepper" aroma. Conversely, the wines made with grapes from lower altitudes were correlated with "red fruits" and "jam" aromas. An important relation between the bell pepper aroma and the lower winter temperature was observed. A strong negative correlation was also observed between seasonal temperatures and vineyard altitude as well as between MIBP content and seasonal temperature of growing grapevines.     

Anthocyanins, phenolics, and color of Cabernet Franc, Merlot, and Pinot Noir wines from British Columbia.

Changes in phenolics (anthocyanins, flavonols, tartaric esters, and total phenolics) during ripening of grapes and in phenolics and color during vinification and aging of Cabernet Franc, Merlot, and Pinot Noir wines were studied. Anthocyanins in grape skins showed variations in accumulation pattern, concentration, and distribution depending on variety and to a lesser extent on season. During vinification, colorless phenolics increased during alcoholic fermentation, reached maximum values at pressing, and remained stable during malolactic fermentation and subsequent storage. Anthocyanins and color density, on the other hand, increased during the early stages of alcoholic fermentation, reached maximum values 2-3 days after the start of fermentation, decreased during malolactic fermentation, and slowly declined during subsequent storage. Viticultural practices that increased cluster sun exposure generally led to higher phenolics and color density of wines, whereas changing yeasts used for fermentation had minimal effects.     

Identification of Cabernet Sauvignon anthocyanin gut microflora metabolites

Anthocyanins are polyphenol antioxidants that have been shown to prevent many chronic diseases, including colon cancer. The compounds are largely metabolized by various enzymes and bacteria in the large intestine, and the health benefits of consuming foods rich in anthocyanins could be due mostly to the effects of these metabolites. In this study, the contents of the large intestine of pigs were used to model anthocyanin metabolism because pig and human intestinal microflora are similar. An anthocyanin extract from Cabernet Sauvignon grapes that contained delphinidin-3-glucoside, petunidin-3-glucoside, peonidin-3-glucoside, and malvidin-3-glucoside was employed. The extract was incubated anaerobically in the contents of the large intestine of freshly slaughtered pigs for 0, 0.5, and 6 h (final concentrations of 20.9, 28.2, 61.4, and 298.0 microM of the above anthocyanin compounds, respectively, at t = 0 h). Anthocyanins and their metabolites were measured by LC-ESI-MS. After 6 h, anthocyanins were no longer detected, and three metabolites were identified as 3-O-methylgallic acid, syringic acid, and 2,4,6-trihydroxybenzaldehyde. Results from this study suggest that consumption of Cabernet Sauvignon grape anthocyanins could lead to the formation of specific metabolites in the human gut, and it is possible that these metabolites offer the protective effect against colon cancer attributed to anthocyanin consumption.     

Assessing the aromatic potential of Cabernet Sauvignon and Merlot musts used to produce rose wine by assaying the cysteinylated precursor of 3-mercaptohexan-1-ol.

The development of a method for assaying S-3-(hexan-1-ol)-L-cysteine, the cysteinylated precursor of 3-mercaptohexan-1-ol (P-3MH), in must has made it possible to study its impact on the aromatic potential of Merlot and Cabernet Sauvignon grape varieties used to produce rose wines in Bordeaux. The original feature of this method is the purification of very small volumes of must (500 microL) containing P-3MH by affinity chromatography and gas-phase chromatography coupled with mass spectrometry of the purified precursor in trimethylsilylated derivative form. Assays of the cysteinylated precursor in Merlot and Cabernet Sauvignon grapes showed that it was mainly located in the grape skins (60%). Prolonged juice-skin contact increased the must's P-3MH content, and this phenomenon was more marked at higher temperatures. Assessment of the aromatic potential of must used to produce rose wines by chemical analysis of an S-cysteine conjugate is mentioned for the first time.     

Effect of macerating enzymes on the oligosaccharide profiles of Merlot red wines

Commercial pectinase preparations are applied in winemaking to improve wine processing and final quality. These preparations contain pectolytic enzyme activities such as polygalacturonases, pectin esterases, pectin lyases, and rhamnogalacturonases. These enzymes modify the polysaccharide and oligosaccharide composition of wines. The influence of various commercial enzyme preparations on wine oligosaccharide composition was studied, on Merlot wines from the Bordeaux area. Wine oligosaccharides were isolated by high-resolution size-exclusion chromatography on a Superdex-30 HR column. The glycosyl residue and glycosyl linkage compositions of the oligosaccharide fractions obtained were determined. The MS spectra of the Merlot oligosaccharide fractions from control and enzyme-treated wines were recorded on an AccuTOF mass spectrometer equipped with an electrospray ionization (ESI) source and a time-of-flight (TOF) mass analyzer. Oligosaccharides in the control wines were partly methylated homogalacturonans, corresponding to smooth regions of pectins, whereas those of the enzyme-treated wines were mostly rhamnogalacturonan-like structures linked with neutral lateral chains, arising from the hairy regions. The enzyme preparations used thus cleaved the rhamnogalacturonan backbone of the hairy zones and demethylated and hydrolyzed the smooth regions. Besides, different structures were detected, depending on the enzyme preparation used, indicating that they contained rhamnogalacturonase activities with different specificities. The oligosaccharide profiles can serve as a marker of enzymatic treatments.     

Composition and cellular localization of tannins in Cabernet Sauvignon skins during growth

For two successive years, cell walls were isolated from the internal part of skin cells of Vitis vinifera L. cv. Cabernet Sauvignon grape berries grown in a vineyard. Procyanidin localization and composition were determined over the course of development. Tannins were mainly localized in the inner cell fraction, due to their biosynthesis and storage. Cell wall tannins always exhibited a higher mean degree of polymerization as compared to the internal cell fraction, which had a constant mDP. The mDP of cell wall tannins also tended to increase at the end of maturation. Our results suggest tannin polymerization near the cell wall but an aggregation in the vacuole during growth. The tannin composition was typical of skins, and small differences were noted between the two cell parts. Surprisingly, epigallocatechin-3-gallate was also detected, although in a very small amount. Epicatechin was present in significant proportions in both fractions, especially as an extension subunit, while epigallocatechin was likewise abundant, also as a terminal subunit. Last, procyanidin composition and organization seemed to be characteristic of the Cabernet Sauvignon variety.     

仪器测定的猪肉质构性状与感官性状的回归分析

为了分析猪肉感官性状与仪器质构性状间的相关性,并利用仪器质构测定指标建立感官性状的预测模型,采集18头6月龄杜洛克×（长白×大约克）杂交商品猪的背最长肌样品,通过24、72、144 h 3种不同时间嫩化处理得到54份质构性状表现有差异的样品。利用warner-bratzler 剪切力测定、质构剖面分析（TPA）和感官评定,分析了各样品的质构性状,并分析了仪器测定与感官测定数据间的线性关系。大部分仪器测定指标均与感官评定值表现出显著或极显著（P＜0.05或P＜0.01）的相关关系。进一步采用主成分-逐步回归法,以仪器测定指标为自变量,感官评定数据为依变量进行回归分析,分别得到具有统计意义的感官硬度、感官弹性和多汁性的预测方程,其中对感官硬度的预测效果较好,方程决定系数（r2）达到0.61;而对感官弹性和多汁性的预测效果较差,方程决定系数（r2）为0.40和0.42。由此明确了猪肉感官性状与仪器质构性状间广泛的相关关系,并采用客观、全面的仪器测定手段和合理的回归方法的优化将肉类感官性状模型的预测效果提高到一个新的水平。     

Anthocyanin composition of Cabernet Sauvignon and Tempranillo grapes at different stages of ripening

Changes in anthocyanins during ripening of Cabernet Sauvignon and Tempranillo grapes were studied over a three year period. The accumulation of anthocyanins showed variations during ripening, especially during the first three weeks after veraison, and the accumulation pattern of those molecules changed only slightly from one year to another. On the other hand, the percentages of the different anthocyanins studied were different for each cultivar, and some changes were observed in both cultivars depending on the weather conditions of the growing season. In warm years the percentages of primitive anthocyanins (delphinidin 3-O-glucoside and petunidin 3-O-glucoside) were slightly lower than in a relatively cool year. Nevertheless, the anthocyanin fingerprints of Cabernet Sauvignon and Tempranillo grapes seem to be rather stable during ripening, despite the sugar content of the grapes.     

不同昼夜温差对赤霞珠葡萄果实香气的影响及转录组分析

为探究不同昼夜温差对酿酒葡萄果实成熟期间挥发性香气合成的影响,以酿酒葡萄赤霞珠为试验材料,通过调控夜间温度改变昼夜温差,设置T_-2.6℃(夜间平均温度为17.0℃,温差为15.1℃)、T_0.5℃(夜间平均温度为20.1℃,温差为12.0℃)、T_3.5℃(夜间平均温度为23.1℃,温差为9.0℃)和CK(夜间平均温度为19.6℃,温差为12.5℃)4组处理,测定分析果实中挥发性香气组分和含量的变化,并进行挥发性香气合成机制的生物信息学分析。结果表明,昼夜温差与可溶性固形物、可溶性糖和可滴定酸含量呈正比;T_-2.6℃和T_0.5℃处理提高了赤霞珠果实中的花香和果香,后续在酿酒过程中可提高葡萄酒一类香气的含量,在酿造干红的同时,也宜于酿造起泡桃红类葡萄酒;T_3.5℃处理提高了果实中的烟草香,为后续酿造葡萄酒提供了更多的三类香气,即陈酿香,在较小温差环境下生长的葡萄酿酒后更适宜储存较长时间,以更好地形成陈酿香。共检测到5 111个差异表达基因,其中T_-2....     

Monomeric, oligomeric, and polymeric flavan-3-ol composition of wines and grapes from Vitis vinifera L. Cv. Graciano, Tempranillo, and Cabernet Sauvignon

The monomeric, oligomeric, and polymeric flavan-3-ol composition of wines, grape seeds, and skins from Vitis vinifera L. cv. Graciano, Tempranillo, and Cabernet Sauvignon has been studied using (1) fractionation by polyamide column chromatography followed by HPLC/ESI-MS analysis, (2) fractionation on C(18) Sep-Pak cartridges followed by reaction with vanillin and acid-catalyzed degradation in the presence of toluene-alpha-thiol (thiolysis). The content of monomers ((+)-catechin and (-)-epicatechin), procyanidin dimers (B3, B1, B4, and B2), trimers (T2 and C1), and dimer gallates (B2-3-O-gallate, B2-3'-O-gallate, and B1-3-O-gallate) ranged from 76.93 to 133.18 mg/L in wines, from 2.30 to 8.21 mg/g in grape seeds, and from 0.14 to 0.38 mg/g in grape skins. In wines, the polymeric fraction represented 77-84% of total flavan-3-ols and showed a mean degree of polymerization (mDP) value of 6.3-13.0. In grapes, the polymeric fraction represented 75-81% of total flavan-3-ols in seeds and 94-98% in skins and showed mDP values of 6.4-7.3 in seeds and 33.8-85.7 in skins. All the monomeric flavan-3-ols and oligomeric procyanidins found in wines were also present in seeds, although differences in their relative abundances were seen. The skin polymeric proanthocyanidins participated in the equilibration of the wine polymeric proanthocyanidin fraction, especially contributing to the polymer subunit composition and mDP.     

Fresh cucumber flavor in refrigerated pickles: comparison of sensory and instrumental analysis

The ability of nonacidified, refrigerated pickled cucumbers to produce the fresh cucumber flavor impact compounds (E,Z)-2,6-nonadienal and (E)-2-nonenal declined during storage. Production of these compounds decreased as the pH of refrigerated cucumbers was reduced. Despite the fact that the concentrations of (E,Z)-2,6-nonadienal and (E)-2-nonenal generated were over 10(5)-fold greater than the threshold levels, it was possible for a sensory panel to consistently detect differences in the intensity of fresh cucumber flavor, provided the pH difference between samples was 1 unit or greater. The presence of spices did not interfere with the ability of panelists to detect differences in fresh flavor intensity. There was a linear correlation between sensory scores and the amount of (E,Z)-2,6-nonadienal produced by cucumbers equilibrated at different pH levels.     

不同施锌量对酿酒葡萄“赤霞珠”锌含量及其品质的影响

以4年生"赤霞珠(Cabernet Sauvignon)"葡萄为研究对象,进行连续2年滴灌[0 kg/hm~2(CK)、24.5 kg/hm~2(T_1)、34.0 kg/hm~2(T_2)、43.5 kg/hm~2(T_3)、53.0 kg/hm~2(T_4)、62.5 kg/hm~2(T_5)]和转色期叶面喷施[0 kg/hm~2(CK)、0.5 kg/hm~2(T_1)、1.0 kg/hm~2(T_2)、1.5 kg/hm~2(T_3)、2.0 kg/hm~2(T_4)、2.5 kg/hm~2(T_5)]两种方式配合施EDTA-Zn的田间试验,探讨强碱性灰钙土(pH8.5)补充锌肥对酿酒葡萄锌含量、生长和品质的影响。结果表明:与不施锌肥(CK)相比,施锌肥处理酿酒葡萄锌含量、粒径、穗长、百粒重和产量分别增加了42.1%～78.7%、2.6%～28.2%、10.1%～22.3%、3.0%～8.8%和17.2%～216.6%。同时,与不施锌(CK)相比,酿酒葡萄的单宁含量降低42.0%～67.9%,花色苷、总酚、可溶性固形物和可溶性糖含量分别提高了0.7%～71.9%、5.0%～80.6%、9.3%～24.0%和10.4%～29.4%,而可滴定酸含量除T_4外没有显著增加。相关分析表明,锌含量与穗长、百粒重、粒径、产量、总酚和可溶性糖均显著相关。综合酿酒葡萄锌含量和品质分析得出T_3处理效果最好。在宁夏贺兰山东麓石灰性土壤条件下,EDTA-Zn施用量45 kg/hm~2左右对于提高酿酒葡萄的锌含量、产量和品质较为适宜。     

Grapevine Irrigation with Saline Water: Effect of Rootstocks on Quality and Yield of Cabernet Sauvignon

The effects of three irrigation salinity levels (1.8, 3.3, and 4.8 dS/m) on ion accumulation and relative turgidity of Cabernet Sauvignon (Vitis vinifea) grapes on ‘Rugerri’ and ‘Salt Creek’ rootstocks were studied in order to introduce more saline water in the Negev Desert of Israel. Leaf samples were taken four times during the summer of 1997 and analyzed for total diffusible ions, which included sodium (Na), calcium (Ca), potassium (K), and magnesium (Mg), and for soluble ions, which included zinc (Zn) and manganese (Mn). Quality and quantity of yield were also measured. The lowest relative turgidity, 0.8, was measured at ECi (electrical conductivity of irrigation water) 4.8 dS/m, which decreased with time to 0.75 for all treatments. The Na/K ratio indicated relative sodium accumulation. It increased fast with time from about 0.1 to 1.4 under high salinity and more slowly, from 0.1 to 0.5, under the low-salinity treatment. Average yield of fresh berries under all treatments (except one) ranged between 8.0 and 8.5 kg/vine under the respective saline and fresh-water irrigation. This difference was not significant, but in view of the first-year experiment this result should be regarded as provisional. The juice quality criteria, as determined by the production of total soluble solids (TSS) pH², improved from 321 to 288, indicating low acidity under the saline treatment and higher acidity under the non-saline treatment. The ratio of TSS/acidity, which changed slightly from 34 to 32, also indicated a moderate reduction in acidity under saline conditions, especially under the ‘Ruggeri’ rootstock. Thus, it was concluded that (a) by the use of saline water the quality of the berries may be improved, (b) ‘Ruggeri’ rootstock was less affected than ‘Salt Creek’ by salinity in both quantity and quality of yield, and (c) relative sodium (Na) content in the lamina and the petiole increased with time during the growth period while relative turgidity declined, indicating a possible accumulation of toxic ions over time.