Hydrolysis and formation of volatile esters in New Zealand Sauvignon blanc wine

The evolution of the varietal thiol 3-mercaptohexanol acetate (3MHA) and other key aroma compounds has been monitored in New Zealand Sauvignon blanc wines stored for 1 year at three different temperatures (5, 10 and 18 °C). The main processes that occurred in the Sauvignon blanc wines during bottle ageing were hydrolysis of 3MHA and other acetate esters, hydrolysis of ethyl esters of fatty acids, and the formation of ethyl esters of branched acids. The kinetic parameters of ester hydrolysis, including reaction rate constants and activation energies, were determined, which allow prediction of future wine composition based upon storage temperature and time. It was found that 3MHA had the highest reaction rate constant, meaning that this compound is the most unstable, particularly at higher storage temperatures, and that it disappeared very fast during wine storage.     

"赛美蓉"与"长相思"葡萄汁挥发性风味物质的分析

通过顶空固相微萃取结合气相色谱-质谱联用技术分析赛美蓉和长相思澄清葡萄汁挥发性风味物质组成,初步定性77种挥发性风味物质,二者共有组分46种。其中醇类物质的种类最多,所占比例最高,分别达到了72.76%和77.69%;酯类物质的种类数量居第二,但所占比例较低,分别为3.67%和2.12%;醛类物质虽然只有8种,但其比例却分别达21.99%和18.82%。主要挥发性组分感官特征分析显示:表现为果香的物质种类最多,表现为清香的物质总离子流量和比例最高。     

Effects of different vinification technologies on physical and chemical characteristics of Sauvignon blanc wines

In order to investigate the effects of cryomaceration and reductive vinification on chemical and physical indices and on antioxidant compounds of Sauvignon blanc wines, four wine-making procedures were applied: traditional white vinification, skin cryomaceration, vinification in a reductive environment, and a combination of the last two procedures. Significant differences were highlighted by both conventional analyses and NMR spectroscopy. The strongest changes were for organic acid concentrations (tartaric, in particular) and phenolic content. Cryomaceration caused a strong precipitation of tartaric acid, which may be desired if grapes have high acidity values. Cryomaceration protected those flavans reactive with vanillin from the action of oxidative enzymes. Vinification in a reductive environment, alone or combined with a cryomaceration step, gave wines with the highest solids content and caused a greater extraction of phenolic compounds from skins compared to traditional winemaking or cryomaceration alone, due to SO₂ solubilisation. Grape oenological expression can be strongly affected by the application of the investigated wine-making procedures.     

Representation of complexity in wine: Influence of expertise

The aim of the present study was to investigate the concept of complexity in wine as a function of domain-specific expertise. Thirty-nine wine professionals and 30 wine consumers participated in interviews aimed at inducing verbal responses concerning their representations of (i) wine complexity in general, (ii) wine complexity in relation to white wine with perceived ageing ability, and (iii) wine complexity in relation to red wine with perceived ageing ability. The verbal data were analysed with the textual data analysis software ALCESTE ( [Reinert, 1983], [Reinert, 1986], [Reinert, 2001] and [Reinert, 2008]). Results showed that wine professionals as a group tended to represent complexity in wine in terms of extrinsic factors such as oenological processes (e.g., lees stirring; use of oak) and terroir variables (e.g., soil; viticulture: see Moran, 2006). On the other hand, wine consumers’ representations of wine complexity were dominated by intrinsic factors relating to their experience of consuming wine (e.g., smell and taste of wines) and were personalised and subjective (e.g., about their own enjoyment and pleasure). Further, wine professionals’ representations clearly differentiated between characteristics of white wine with ageing potential and characteristics of red wine with ageing potential whereas those of wine consumers did not. The results are discussed in terms of the salient components of the concept of complexity in wine, including wine judged to have ageing ability, along with the cognitive processing associated with wine expertise.     

Volatile composition and aromatic attributes of wine made with Vitisvinifera L.cv Cabernet Sauvignon grapes in the Xinjiang region of China: effect of different commercial yeasts

The Xinjiang region is a major grape- and wine-production area in China, but the region’s notably high temperatures in the summer and year-round intense sun exposure play negative roles in the aroma, complexity, and elegance of Cabernet Sauvignon wine. In this study, Cabernet Sauvignon grapes harvested in this region were fermented on an industrial scale using four commercial yeast strains (L2323, D254, RVA, and CECA) and spontaneous yeast (NF). The results showed that a total of 123 volatile compounds were detected and 15 volatile compounds significantly contributed their flavor notes to the wine’s overall aroma. The use of RVA and CECA strains resulted in wine with higher concentrations of higher alcohols, terpenes and norisoprenoids. However, the D254-fermented wine showed high level of esters and carbonyl compounds. Wine fermented with the L2323 and D254 strain possessed a stronger fruity aroma, whereas the RVA strain enhanced the herbaceous, chemical, and fatty aromas in wine. Principal component analysis revealed that a significant aromatic feature difference was observed in these wines after alcoholic and malolactic fermentation. The use of different commercial yeast strains altered the aromatic profile of Cabernet Sauvignon wine.     

Influence of water and nitrogen deficit on fruit ripening and aroma potential of Vitis vinifera L cv Sauvignon blanc in field conditions

S‐Cysteine conjugate precursors of three volatile thiols were monitored in Vitis vinifera L cv Sauvignon blanc grapes during fruit ripening to assess the influence of vine water and nitrogen status on the grape aroma potential in field conditions. Four dry farmed plots were studied in the Pessac‐Léognan and Graves appellations (Bordeaux area) in 1998, which was a very dry vintage, and in 1999, when regular summer rainfall occurred. Soil water‐holding capacity ranged from very low to high. Soil total nitrogen content was related to soil organic matter content, which was highly variable on the four plots. Vine vigour was enhanced by both high water and nitrogen status. Major compounds in grapes depended mainly on vine water status. Water deficit‐stressed vines produced small berries with low sugar and low total acidity. Grape aroma potential was highest in vines under mild water deficit and moderate nitrogen supply. Severe water deficit stress seemed to limit aroma potential, as did nitrogen deficiency. Consequences for site selection and irrigation management for Sauvignon blanc are discussed. Copyright © 2004 Society of Chemical Industry     

网购赤霞珠干红葡萄酒品质特征与价格的关联分析

选用某网站3个价格区段的赤霞珠干红葡萄酒为材料,采用搅拌棒吸附萃取-气相色谱质谱联用法（SBSE-GC-MS）和超高效 液相色谱法（UPLC）分别对葡萄酒中的香气成分和单体酚进行检测分析。 结果表明,3个价格区段的葡萄酒共检出45种香气成分,其 中酯类24种、高级醇6种、脂肪酸8种、醛酮类3种及其他香气物质4种。 价格较高的葡萄酒中17种香气成分的含量相对较高,价格与检测 到的单体酚物质中香豆素、山奈酚、没食子酸、咖啡酸、丁香酸、水杨酸以及白藜芦醇含量呈正相关（P＜0.05）,相关系数R2均＞0.85。 总酚和总花色苷含量在不同价格区段酒样中差异显著（P＜0.05）,其含量最高分别为1 680.74 mg/L、606.78 mg/L;单宁含量差异不 显著（P＞0.05）。     

赤霞珠干红葡萄酒在不同子产区香气特征的差异

以宁夏贺兰山东麓5个不同子产区石嘴山市、银川市贺兰县、西夏区、永宁县和吴忠市红寺堡区的17款赤霞珠干红葡萄酒为研究对象,采用顶空固相微萃取与气相色谱-质谱联用法(headpace solid-phase microextraction and gas chromatography-mass spectrometry,HS-SPME-GC-MS),分析酒样的香气物质以及气味活性值(odor activity value,OAV),确定具有感官贡献的香气物质,结合主成分分析研究5个子产区之间的相关性。结果表明,酒样香气物质在组成上具有一致性,主要是醇类和酯类物质。此外,大马士酮香气贡献最为突出,使得宁夏贺兰山东麓赤霞珠干红葡萄酒香气主要具有花香和果香特征。主成分分析结果表明,利用植物香指数和脂香指数可区分不同子产区的香气特征,辛酸甲酯、乙酸苯乙酯、月桂酸乙酯;2,4-二叔丁基苯酚;苯乙醇;大马士酮和癸酸乙酯;乙酸异戊酯分别对石嘴山市、银川市贺兰县、西夏区、永宁县和吴忠市红寺堡区葡萄酒香气有重要贡献。聚类结果表明,石嘴山市和银川市西夏区葡萄酒香气更为接近。     

赤霞珠和梅鹿辄干红葡萄酒的香气分析

本文以王朝赤霞珠、梅鹿辄两种干红葡萄酒为研究对象,利用液液萃取法提取香气成分,结合气相色谱-质谱联用技术对其进行分析,两种干红葡萄酒中共检出77种香气组分,根据计算机检索定性并利用面积归一化法对组分进行定量,鉴定出70种香气组分。     

叶幕形和留穗量对赤霞珠葡萄酒单体酚类物质的影响

以山西晋中南地区赤霞珠为材料,采用高效液相色谱-质谱联用技术（HPLC-MS）,研究不同叶幕形和每株留穗量对所酿造的干红葡萄酒中单体酚类物质种类和浓度的影响。结果表明,相比于直立叶幕,V形叶幕可提高成熟葡萄果实的成熟度,V葡萄酒中酰化花色苷的含量（33.46 mg/L）和非花色苷单体酚类物质的总量（286.25 mg/L）分别是直立形叶幕的2.80倍和2.18倍。在直立叶幕下,适当的减少单株果穗数量,可增加葡萄酒中花色苷单体酚类物质的种类和含量,此外随着每株留穗量的减少,非花色苷单体酚类物质总量有逐渐增多的趋势。在山西晋中南地区,对于赤霞珠而言,适度减少每株留穗量或运用V形叶幕栽培管理可以提高葡萄酒中单体酚类物质含量。     

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。