Dependence of wine sensory attributes on vine water status

The dependence of wine sensory attributes on the water status of the source vines was determined following vineyard irrigation treatments which included early and late season water deficits and continually irrigated vines. In both seasons, the experimental wines made from the different irrigation treatments did not differ in the concentration of residual sugar or ethanol, titratable acidity, or pH. The concentrations of anthocyanins and total soluble phenolics in the wines were greater from water deficit treatments than from continually irrigated vines. For sensory evaluation, a novel protocol for paired comparisons was developed to test separately for differences in wine appearance, flavour, taste and aroma; differences were detected for each wine comparison. In both seasons, continually irrigated wine differed from early and late season water deficit wine, and early season water deficit wine differed from late season water deficit wine in appearance, flavour, taste and aroma. The sensory differences were not attributable to differences in vine yield or fruit maturity. When professional wine tasters were sampled using similar tests, a majority was able to detect visual but not flavour differences between a selected pair of wines. It is concluded that, where vine water status can be altered, irrigation offers a means to manipulate wine sensory characteristics in the vineyard.     

Sensory evaluation of black pigmented rice (Oryza sativa cv. Poireton) wine fortified with probiotic Lactobacillus acidophilus ATCC 4356 and Lactobacillus sakei ATCC 15521 using fuzzy logic

Rice wine was prepared in the laboratory from a black pigmented rice (cv. Poireton) using standardized methodology. The wine was fortified with the probiotic strains Lactobacillus acidophilus ATCC 4356 and Lactobacillus sakei ATCC 15521 and allowed to undergo a storage period of 28 days at 4°C. These rice wines were compared with a commercial wine used as a standard reference wine. A panel consisting of 30 judges performed the sensory evaluation. The scores obtained were based on the quality attributes of colour, taste, aroma and alcoholic strength. Analysis of the sensory scores and ranking of the different samples were performed using fuzzy analysis. The quality attributes were also ranked according to their importance in the overall acceptability. Colour and alcoholic strength were accorded the highest importance, compared with aroma and taste, as quality attributes. The rice wines were rated as ‘not satisfactory’, ‘fair’, ‘medium’, ‘good’ and ‘excellent’ on the sensory scale. Out of the wines prepared, black pigmented rice wine fortified with L. acidophilus was the most acceptable and was ranked as ‘good’, which was also at par with the commercial wine. On the other hand, black pigmented rice wine fortified with L. sakei and black pigmented rice wine fortified with L. acidophilus and L. sakei were ranked in the ‘satisfactory’ category followed by the unfortified wine ranked in the ‘fair’ category. Copyright © 2015 The Institute of Brewing & Distilling     

The influence of yeast on the aroma of Sauvignon Blanc wine

The main objective of this study was to investigate the effect of different Saccharomyces cerevisiae wine yeast strains on the concentration of aroma-enhancing volatile thiols and fermentation metabolites in Sauvignon Blanc wine. Seven commercial wine yeast strains were selected based on their putative ability to modulate the concentrations of the fruity volatile thiols, 4-mercapto-4-methylpentan-2-one (4MMP), 3-mercapto-hexanol (3MH) and 3-mercapto-hexylacetate (3MHA). Each of these yeasts was used to produce Sauvignon Blanc wines under controlled conditions, in triplicate, in 20-L quantities. The levels of 4MMP, 3MH and 3MHA in these wines were quantified using the p-hydroxymercuribenzoate method. In addition, a total of 24 volatile yeast-derived fermentation aroma compounds were also quantified using headspace solid-phase microextraction coupled with gas chromatography mass spectrometry (HS-SPME–GC–MS). Formal sensory analysis was conducted by 12 trained assessors and, additionally, a panel of 24 experienced wine industry professionals assessed the wines and ranked them in order of preference. The results indicated that the yeast strains varied significantly in terms of their capabilities to (i) produce volatile thiols and fermentation metabolites; and (ii) to modulate the varietal characters of Sauvignon Blanc wine. Yeast strains that produced the highest levels of volatile thiols were responsible for wines with the highest perceived intensity of fruitiness, and these wines were preferred by the tasting panels. While the ‘green’ characters in Sauvignon Blanc wines can be manipulated through vineyard management, the ‘tropical fruity’ characters appear to be largely dependent on the wine yeast strain used during fermentation. Therefore, the choice of yeast strain offers great potential to modulate wine aroma profiles to definable styles and predetermined consumer market specifications.     

Effect of thermal treatment on physicochemical composition and sensory qualities,including ‘foxy’ methyl anthranilate of interspecific variety Golden Muscat (Vitis vinifera × Vitis labrusca) fortified wine made in Taiwan

BACKGROUND: The major defect of the interspecific variety Golden Muscat (Vitis vinifera × Vitis labrusca) is the inheritance of the specific foxy off‐flavours from the parent species Vitis labrusca. Thermal treatment is a traditional method of producing fortified wine that originated from the subtropical Portuguese island of Madeira. This technique was used to treat Golden Muscat fortified wine in order to investigate the effects of thermal treatment on the physicochemical composition and sensory qualities of the wine. RESULTS: The control wine had the lowest total phenol concentration, total flavonol concentration and total acidity. Increased colour intensity in all thermal‐treated samples was detected. The amount of foxy methyl anthranilate in the wine decreased significantly (P < 0.05) after thermal treatment. Panellists indicated that, compared to the control wine, the thermal‐treated wines had higher flavour complexity, flavour intensity, persistence and balance. The control wine exhibited an unpleasant foxy flavour. CONCLUSION: These results suggest that the thermal treatment technique can be used for the production of Golden Muscat fortified wines with desirable flavour. This technique could assist local winemakers to produce an interspecific variety Golden Muscat fortified wine of acceptable quality. Copyright © 2009 Society of Chemical Industry     

Temporal and spatial water use on irrigated and nonirrigated pasture-based dairy farms

Robust information for water use on pasture-based dairy farms is critical to farmers' attempts to use water more efficiently and the improved allocation of freshwater resources to dairy farmers. To quantify the water requirements of dairy farms across regions in a practicable manner, it will be necessary to develop predictive models. The objectives of this study were to compare water use on a group of irrigated and nonirrigated farms, validate existing water use models using the data measured on the group of nonirrigated farms, and modify the model so that it can be used to predict water use on irrigated dairy farms. Water use data were collected on a group of irrigated dairy farms located in the Canterbury, New Zealand, region with the largest area under irrigation. The nonirrigated farms were located in the Manawatu region. The amount of water used for irrigation was almost 52-fold greater than the amount of all other forms of water use combined. There were large differences in measured milking parlor water use, stock drinking water, and leakage rates between the irrigated and nonirrigated farms. As expected, stock drinking water was lower on irrigated dairy farms. Irrigation lowers the dry matter percentage of pasture, ensuring that the amount of water ingested from pasture remains high throughout the year, thereby reducing the demand for drinking water. Leakage rates were different between the 2 groups of farms; 47% of stock drinking water was lost as leakage on nonirrigated farms, whereas leakage on the irrigated farms equated to only 13% of stock drinking water. These differences in leakage were thought to be related to regional differences rather than differences in irrigated versus nonirrigated farms. Existing models developed to predict milking parlor, corrected stock drinking water, and total water use on nonirrigated pasture-based dairy farms in a previous related study were tested on the data measured in the present research. As expected, these models performed well for nonirrigated dairy farms but provided poor predictive power for irrigated farms. Partial least squares regression models were developed specifically to simulate corrected stock drinking water, milking parlor water, and total water use on irrigated dairy farms.     

Influence of fruit ripeness and juice chaptalisation on the sensory properties and degree of typicality expressed by Sauvignon Blanc wines from Marlborough,New Zealand

Background and Aims: Interest in the typical sensory properties exhibited by Sauvignon Blanc wines from Marlborough, New Zealand, is increasing. Although critical from a winemaking standpoint, there is a significant lack of data concerning the extent to which these typical sensory characteristics are affected by fruit ripeness at harvest and juice chaptalisation. Methods and Results: Experimental Marlborough Sauvignon Blanc wines fermented from fruits at three different ripeness stages, with or without juice chaptalisation, were assessed by a panel of wine professionals from Marlborough. Results suggest that the balance between green and fruity ripe flavours that makes a Marlborough Sauvignon Blanc typical of its style would originate from the fruit ripeness at harvest. We also report that juice chaptalisation can modulate the wines' taste and mouthfeel properties and significantly affect their typicality as Marlborough Sauvignon Blanc. Conclusions: The production of Marlborough Sauvignon Blanc wines that well represent their specific style relies primarily on the ripeness of the fruit at harvest, the impact of which can be modulated by juice chaptalisation. Significance of the Study: This is the only study that has considered fruit ripeness and juice chaptalisation as two factors that condition the sensory properties and degree of typicality expressed by Marlborough Sauvignon Blanc wines.     

The impact of over‐maturation on the sensory and nutritional quality of Gouqi (Chinese wolfberry) wine

This study compared the nutritional quality and sensory attributes of wine made from dried Gouqi berries that were mature (NDG), mildly over‐matured (MDG) and severely over‐matured (SDG). Whilst these wines had the similar physicochemical properties, the MDG wine possessed higher polysaccharide levels, whereas the highest total flavonoids were found in the NDG wine. A slight difference in the amino acid composition was observed in these wines, whereas they exhibited the same biogenic amines composition. The MDG and SDG wines exhibited weaker fruity, floral and caramel aromas compared with the NDG wine. However, these wines showed similar chemical and fatty aromas. Sensory evaluation revealed that these wines could be distinguished by panelists, and the NDG wine was preferred by most tasters, followed by the MDG and SDG wines. These results suggest that the Gouqi wine made from mature berries exhibits the best nutritional and organoleptic quality. However, the over‐matured and severely over‐matured berries could also be useful for Gouqi berry wine production but with different nutritional and sensory properties. Copyright © 2017 The Institute of Brewing & Distilling     

Evaluating the value of replicate tastings of a given wine: bio-statistical considerations

Wine judges were randomly selected from the membership of the American Association of Wine Economists (AAWE) to participate in a blind triplicate tasting of two South African varietals: one Sauvignon Blanc and one Pinotage; as well as a blind tasting of a single pouring of five additional Sauvignon Blanc wines and five additional Pinotage wines. It was hypothesized that those wine Tasters who scored the triplicate wines reliably would also score the single poured wines reliably; and, conversely, those who were unreliable on the triplicate wines would also be unreliable on the additional five wines. The results were substantially confirmative for the Sauvignon varietals, but only minimally confirmative for the Pinotage varietals. Two possible reasons are, first, the simpler structure of Sauvignon Blanc (a white wine) and possible palate fatigue for the more complex Pinotage (a red wine).     

放汁法同时酿造干红和桃红葡萄酒及其酒质和抗氧化活性分析

以烟台产区的蛇龙珠葡萄为原料,采用放汁法同时酿造干红和桃红葡萄酒,对其发酵进程进行了检测,对陈酿后的葡萄酒进行主要理化指标和抗氧化活性分析。结果表明：桃红和干红葡萄酒均能正常发酵。放汁量不同,其葡萄酒的主要理化指标和抗氧化活性也不同,其中各组之间的干浸出物和总酚含量及还原力均存在显著差异。相关分析表明：葡萄酒的抗氧化活性不仅与酚类物质含量有关,还与干浸出物、蛋白质、酒石酸、总糖和还原糖含量等指标存在显著或极显著相关性。通过因子分析提取了2 个公因子,综合因子得分排名首位的是放汁量30%的干红葡萄酒,其品评得分同样排在首位,总体评价为口感醇厚,酒体丰满,具有明显的单宁结构感;品评得分排名第二的是桃红葡萄酒,其色泽淡雅,香气浓郁,口感清新。放汁法同时酿造干红和桃红葡萄酒值得在生产中推广应用。     

Effect of storage temperature on the chemical composition and sensory profile of Sauvignon Blanc wines

Background and Aims: Most white wines lose fresh and fruity characteristics, associated with volatile esters, during ageing in the bottle. A higher storage temperature accelerates these changes. The aim of this study was to examine the influence of storage temperature on the chemical and sensory properties of Sauvignon Blanc wines. Methods and Results: Three commercially bottled Sauvignon Blanc wines from the 2008 and 2009 vintages were stored at 5, 10, 18°C and at room temperature for 12 months. Wines stored at warmer temperatures (18°C and room temperature) contained lower concentrations of acetate esters, including the prominent varietal thiol 3MHA, and ethyl esters of fatty acids, than the wines stored at cooler temperatures (5 and 10°C). A warmer temperature accelerated the rate of ester hydrolysis. Conversely, the concentrations of ethyl esters of branched acids were higher in wines stored at the warmer temperatures. The sensory profile of the wines was assessed after 12 months for the two 2008 wines and after 8 months for the 2009 wine. The wines stored at cooler temperatures were characterised by higher fruity and fresh vegetal aromas, whereas the wines stored at warmer temperatures exhibited the opposite sensory profile, with dominant woody/smoky/oaky, buttery, flinty and canned asparagus notes. Conclusions: These results indicate that temperature‐dependent hydrolysis processes are critical for Sauvignon Blanc aroma stability during the first year in the bottle. Significance of the Study: Cool storage temperature conditions can significantly increase the shelf‐life of Sauvignon Blanc wines by preserving their fruity and fresh green characters.     

赤霞珠、蛇龙珠和玫瑰香葡萄酒芳香性成分的差异性研究

芳香类物质种类及含量的差异是决定葡萄酒风味的重要因素。本文对赤霞珠、蛇龙珠和玫瑰香葡萄酒的芳香性成分进行探讨分析。结果表明,3种葡萄酒中3-甲基-1-丁醇的含量最高,相对含量分别为20.61%、21.00%和15.54%;次之为丁二酸单乙酯,含量分别为17.90%、8.94%和16.55%;再次为乳酸乙酯,含量分别为12.36%、17.01%和12.06%。赤霞珠干红葡萄酒中特有的检出成分为乙酸异戊酯和丙酸;玫瑰香葡萄酒中特有的检出成分为3-乙氧基丙醇。蛇龙珠葡萄酒中没有检出1-丁醇、4-酮基-戊酸乙酯和癸酸乙酯,赤霞珠和玫瑰香葡萄酒中均有上述成分;玫瑰香葡萄酒中未检测到(顺)3-己烯-1-醇和糠醇。     

AROMA COMPOUNDS AS MARKERS OF WINE QUALITY IN THE CASE OF MALVAZIJA ISTARSKA YOUNG WINE

ABSTRACT

In order to investigate the relationship between sensory and gas chromatographic analysis data, and to establish if particular aroma compounds could be used as Malvazija istarska young wine quality markers, 30 samples of Malvazija istarska young wine were subjected to sensory evaluation and gas chromatographic analysis of aroma compounds. Linear regression and principal component analysis were applied in order to establish the relations between sensory evaluation scores and aroma compound concentrations in corresponding wines. The most important contributors to the characterization and differentiation of wines evaluated with higher sensory evaluation scores were isoamyl acetate, ethyl hexanoate, ethyl octanoate, ethyl decanoate, hexanoic acid, octanoic acid and decanoic acid. On the other hand, wines evaluated with lower sensory evaluation scores were characterized and differentiated by higher amounts of isoamyl alcohol and isobutanol. Mentioned esters and acids were also found to be the most important variables for the classification of these wines according to quality using stepwise linear discriminant analysis (SLDA). The evaluation of the SLDA model was performed by cross‐validation, obtaining an average percentage of correct classification of 100.0%, and of correct prediction of 89.3%. The results of this investigation suggest that above‐mentioned esters, acids and alcohols could be used as markers of Malvazija istarska young wine quality.

PRACTICAL APPLICATIONS

Wine aroma is one of the most important parameters responsible for its quality, and hence for consumer acceptance. Sensory evaluation is the most common technique for controlling the organoleptic quality of wine, but it is not always feasible, since it requires specific conditions, and a group of trained expert tasters that can only assess a relatively small number of wine samples for a day. Moreover, the subjectivity of panelists can affect the evaluation in a great measure. The approach proposed in this work suggests the use of a nonsubjective instrumental technique such as gas chromatography for the analysis of volatile aroma compounds as a complementary tool for wine quality control able to predict, confirm or to correct the results of Malvazija istarska young wine sensory evaluation. Although this model is yet far from being practically implemented, information obtained could be used as a starting ground. Moreover, it was assumed that the approach proposed in this work is likely to be applied successfully on the differentiation and classification of other types of wine according to quality.     

Alcohol,Tannins, and Mannoprotein and their Interactions Influence the Sensory Properties of Selected Commercial Merlot Wines: A Preliminary Study

The objective of this study was to assess the influence of the interaction among alcohol, tannins, and mannoproteins on the aroma, flavor, taste, and mouthfeel characteristics of selected commercial Merlot wines. Merlot wines (n = 61) were characterized for wine chemistry parameters, including pH, titratable acidity, alcohol, glucose, fructose, tannin profile, total proteins, and mannoprotein content. Agglomerative clustering of these physicochemical characteristics revealed 6 groups of wines. Two wines were selected from each group (n = 12) and profiled by a trained sensory evaluation panel. One wine from each group was evaluated using the electronic tongue (e‐tongue). Sensory evaluation results showed complex effects among tannins, alcohol, and mannoproteins on the perception of most aromas, flavors, tastes, and mouthfeel attributes (P < 0.05). The e‐tongue showed distinct differences among the taste attributes of the 6 groups of wines as indicated by a high discrimination index (DI = 95). Strong correlations (r² > 0.930) were reported between the e‐tongue and sensory perception of sweet, sour, bitter, burning, astringent, and metallic. This study showed that interactions among wine matrix components influence the resulting sensory perceptions. The strong correlation between the e‐tongue and trained panel evaluations indicated the e‐tongue can complement sensory evaluations to improve wine quality assessment.     

Partial Dealcoholization of Red Wines by Membrane Contactor Technique: Effect on Sensory Characteristics and Volatile Composition

Recently, the European Union regulation has fixed the maximum permitted dealcoholization level at 2 %; however in some cases, higher dealcoholization levels could be necessary. It is assumed that higher levels of dealcoholization could negatively affect the organoleptic quality of wine, but little data on this item is available. In the present study, two red wines (cv. Aglianico) with different initial alcohol contents (15.37 and 13.28 % v/v), were partially dealcoholized at three levels (?2, ?3, ?5 % v/v), by a polypropylene hollow fibre membrane contactor apparatus. In order to evaluate if dealcoholized wines differed from the untreated ones, triangle sensory tests were performed. Both ?2 % wines were not perceived as different from the standard wines, while both ?5 % wines were different. Sensory profiles and overall quality ranking were obtained by a selected and trained panel. Dealcoholization caused a modification of the sensory profiles, and the greatest differences were found after a dealcoholization of 5 % v/v. The most decreased olfactory notes were those of “Red fruits”, “Cherry” and “Spicy”, which is very important for the sensory quality of red wine. Concerning taste, both ?5 % dealcoholized wines were more astringent than the correspondent untreated ones. Slighter differences were found for the other degrees of dealcoholization. The analysis of the volatile compounds, both free and glycoconjugated was performed by solid-phase extraction and gas chromatography mass spectrography analysis. While the composition of the glycoconjugated volatile fraction was almost not affected, many free compounds were decreased, most of all esters and alcohols, with an increasing amounts as the level of dealcoholization raised.     

感官定量描述分析对竹酒风味特征的研究

参照国内外酒类风味轮建立的方法及国标GB/T 16861—1997《感官分析 通过多元分析方法鉴定和选择用于建立感官剖面的描述词》,对不同工艺生产的40个竹酒进行感官描述分析,获得竹酒风味特征的描述语,采用聚类分析（CA）对香气、口感、口味的34个描述语进行归类,Pearson相关性分析考察同一类别下描述语之间的相关性。为进一步验证聚类分析（CA）的结果,方差分析筛选不同竹酒中具有显著差异的风味描述语,绘制竹酒风味轮。根据结果最终保留14个香气特征描述语、8个口感特征描述语、3个口味特征描述语、5个颜色特征描述语作为竹酒的风味轮,并采用对比分析和雷达图对6个具有代表性的竹酒样品进行分析,结果表明,采用活竹竹节陈酿工艺的竹酒香气淡雅舒适,口感淡爽清甜;采用竹制容器陈酿或陶缸浸泡竹片陈酿工艺的竹酒则香气浓郁复杂,竹木香的风格更加突出。     

Perceived minerality in sauvignon blanc wine: Chemical reality or cultural construct?

The study aimed to determine the relationship between perceived mineral character in wine and wine chemical composition. We investigated the sensory properties and chemical composition of sauvignon blanc wines from two major sauvignon-producing countries, New Zealand and France. Sensory experiments employing 16 wines (8 French, 8 New Zealand) were conducted in Marlborough, New Zealand and in three regions of France, namely Bordeaux, Burgundy, and the Sancerre/Loire region. Wine professionals (31 New Zealanders and 32 French professionals) sensorially characterised the 16 wines under three conditions, bouquet only (ortho-nasal olfaction), palate only (nose clip condition), and full tasting (global condition: ortho-nasal olfaction, retronasal olfaction, taste, trigeminal stimulation). Sensory data from the global condition only are reported in this article. Physical and chemical analyses conducted on all wines included wine standard parameters, elemental composition, volatile aroma composition, and measures of organic acids. Major results demonstrate that (i) on average French and New Zealand wines were perceived similarly in intensity of mineral character, although judgments to individual wines differed as a function of participant culture; (ii) French and NZ participants drew on different information to make their sensory judgments; and (iii) several aspects of wine composition associated positively with perception of mineral character while others associated negatively, the significant associations differing as a function of participant culture.     

Reduction of lead content and other elements in wine using pectic acid

A procedure for reducing the Pb content in wines containing high levels of Pb is described. The reduction of Pb by means of pectic acid (PA) depends on the quality grade of the wine. In "Auslese" (wine A) 6250 mg PA/l diminished Pb content in 24 h from 0.88 mg/l to 0.28 mg/l; in "Sp?tlese" (wine B) from 0.83 mg/l to 0.06 mg/l. Under the same conditions the content of Fe, Zn, Cu decreased in wine A from 8.85 mg/l to 7.05 mg/l, from 4.75 mg/l to 1.25 mg/l, from 0.67 mg/l to 0.57 mg/l and in wine B from 6.70 mg/l to 5.41 mg/l, from 1.17 mg/l to 0.28 mg, 0.46 mg/l to 0.28 mg/l, respectively. PA is removed almost quantitatively by filtration. Sensory properties of treated wines were unchanged with concentrations of PA of 750 mg and 1500 mg/l. A slight effect on taste at 6250 mg PA/l wine cannot be excluded. On account of its high affinity to Pb, PA will probably remove Pb from other liquid foods as well.     

Contents of 3‐alkyl‐2‐methoxypyrazines in musts and wines from Vitis vinifera variety Cabernet Sauvignon: influence of irrigation and plantation density

The influence of irrigation and plantation density on the methoxypyrazine content in musts and wines has been studied. Samples were monitored throughout grape ripening and wine‐making. 3‐Isobutyl‐2‐methoxypyrazine, 3‐sec‐butyl‐2‐methoxypyrazine and 3‐isopropyl‐2‐methoxypyrazine were identified and quantified. Samples from irrigated vines had significantly higher average contents of 3‐isobutyl‐2‐methoxypyrazine than samples from non‐irrigated plants. Average levels of this compound were also higher in samples from vines with the higher plantation density. Copyright © 2005 Society of Chemical Industry