Sensory Evaluation Of Wines Research Articles

THE WINE QUALITY DESCRIPTION OF DIFFERENT ORIGIN EVALUATED BY MODERN CHEMOMETRIC APPROACH

The main chemical parameters such as content of sugar (glucose and fructose), organic acid (total acids, malic and tartaric acids), total phenolics and the antioxidant activity in 9 dry white wines with PDO of 3 varieties (Pinot Blanc, Riesling, Sauvignon blanc) from 3 countries (Slovakia, Hungary, Austria) were studied in this work in order to identify possible differences in their quality affected by geographical origin. The wine samples were examined by the FTIR and spectrophotometry methods (TPC and DPPH). As supporting parameters, alcohol and glycerol content were used and sensory evaluation of wines was performed. For the statistical evaluation were used ANOVA and PCA methods. Austrian wines in general, were characterized by high glucose and fructose content, high TPC and antioxidant activity. Higher results of these parameters are characteristic especially for the Austrian varieties Pinot blanc and Sauvignon blanc which originated from the same wine-region in Austria. Sauvignon variety from Slovakia was characterized by higher total acid content, especially in the case of tartaric acid. Statistical evaluation was helpful to show several differences, especially in the case of PCA application. Just Riesling variety from all countries of origin was so similar that it was not possible to be strictly distinguished using PCA. Wines from Hungary (Sauvignon and Pinot blanc) showed higher content of alcohol and glycerol, as they are produced by the sugar fermentation. Wines from Slovakia were evaluated as the best samples among selected ones within their sensory evaluation.

Effect of Microwave Maceration and SO2 Free Vinification on Volatile Composition of Red Wines.

This study evaluates the effect of microwave treatment in grape maceration at laboratory scale on the content of free and glycosidically bound varietal compounds of must and wines and on the overall aroma of wines produced with and without SO2. The volatile compounds were extracted by solid phase extraction and analyzed by gas chromatography–mass spectrometry, carrying out a sensory evaluation of wines by quantitative descriptive analysis. Microwave treatment significantly increased the free and bound fraction of most varietal compounds in the must. Wines from microwave maceration showed faster fermentation kinetics and shorter lag phase, resulting in an increase in some volatile compounds of sensory relevance. The absence of SO2 caused a decrease in concentration of some volatile compounds, mainly fatty acids and esters. The sensory assessment of wines from microwave treatment was higher than the control wine, especially in wines without SO2, which had higher scores in the “red berry” and “floral” odor attributes and a more intense aroma. This indicates that the pre-fermentative treatment of grapes with microwaves could be used to increase the wine aroma and to reduce the occurrence of SO2.

Effect of Power Ultrasound Treatment on Free and Glycosidically-Bound Volatile Compounds and the Sensorial Profile of Red Wines.

This study presents the effect of the application of high-power ultrasound to crushed grapes, at a winery-scale, on the content of varietal volatile compounds (free and glycosidically-bound) in musts and on the overall aroma of wines. Two different frequencies (20 kHz and 28 kHz) were tested and the combination of grape sonication and different maceration times on wine aroma was also evaluated. The volatile compounds were isolated by solid phase extraction and analyzed by gas chromatography-mass spectrometry, carrying out a sensory evaluation of wines by quantitative descriptive analysis. Sonication produced an increase in the concentration of free varietal compounds such as C6 alcohols, terpenes and norisoprenoids in musts and also in wines made by 48 h of skin maceration, being less efficient in the extraction of the bound fraction. Fermentation compounds were also positively affected by ultrasound treatment, although this effect was variable depending on the frequency used, the maceration time and the type of compound. All the wines made from sonicated grapes had better scores in the evaluated olfactory attributes with respect to the control wines. Our results indicate that sonication could produce an increase in the content of some volatile compounds of sensory relevance, obtaining wines with an aroma quality similar or higher than those elaborated with longer maceration times.

Study of consistency of expert evaluations of wine sensory characteristics by positional analysis

Individual characteristics inherent in the expert, as well as their physical and psycho-emotional state subject to the influence of random, uncontrollable factors, contribute to subjectivity in the sensory evaluation of wines. With great variability of opinions, the final results of sensory evaluation may become doubtful. The presence of a random component in the sensory evaluation justifies the use of statistical methods for analyzing the consistency of expert evaluations. Along with Spearman's correlation coefficients and Kendall matching, Cronbach alpha criterion was used to assess the consistency of expert opinions. The advantages of positional analysis have been discussed – Cronbach's alpha criterion is calculated not by the rank of expert points, but by the initial point scale considering its variability; it allows to evaluate the contribution of each expert to the consistency of expert evaluations, as well as the reliability of the total scale of points set for each wine sample. Based on the data analysis from sensory evaluation of the quality of dry red and white wines of Russian production, the results of the consistency study of expert evaluations as well as the reliability of the total score scale have been presented. What is more, analysis of the “loyalty” of experts in evaluating the quality of wines has been performed.

BACTERIOLOGICAL QUALITY AND SENSORY EVALUATION OF WINE PRODUCED FROM BLENDS OF DATE PALM FRUIT AND CUCUMBER JUICE USING Saccharomyces cerevesiae

Bacteriological quality and sensory evaluation of wine produced from blends of date palm fruit and cucumber juice using Saccharomyces cerevisiae was investigated. The yeast was isolated and identified using standard techniques. The S. cerevisiae inoculum was produced using standard procedures and used to ferment the blends of date and cucumber to produce wine. Five (5) samples of wine were produced from date and cucumber at various concentration of substrates, anaerobically (Aerobic fermentation were terminated after 6 days and the fermented ‘’musts’’ were sieved to remove the shaft and debris of the crushed fruits.During the anaerobic phase of fermentation, the filtrates obtained after sieving the ‘’musts’’ were transferred into anaerobic fermentation round bottom flask (s) and incubated at room temperature. An air trap were fixed to the fermenting jars. Fermentation were terminated after four (4) weeks). Physicochemical, microbiological and sensory evaluation (using 7 point hedonic scale by 20 panelist) of the produced wine were studied. The yeast was identified as Saccharomyces cerevisiae. The physiochemical analysis of the produced wines showed that percentage of alcoholic content of wine B had the highest at 16.6 %, as Wine A had 15.8 %, Wine D had 13.17 %, Wine C had 11.17% and Wine E had 10.18% of alcohol content after fermentation. The suspected bacteria isolate were Corynebacterium sp. Neisseria sp, Corynebacterium sp., Micrococcus sp. Enterobacteriaceace sp. Lactobacillu sp.and Micrococcus sp. and some fungi sp. were isolated from the wines before pasteurization for sensory evaluation. But no microorganisms were detected after pasteurization of the produced wines. The sample C (Date and Cucumber) of ratio 3:1 was significantly preferred (p<0.05) from other wine A, B, D and E in respect to the aroma, test and appearance and over all acceptability. The S. cerevisiae used in the production of the wines gave excellent results. Harnesing the date and cucumber for wine production will reduce post-harvest loss of the fruit (wastage), improve, conribute to the economy and reduce unemployment.

Einfluss von Zucker‑, Ethanolgehalt und Farbe des Weines auf die sensorische Bewertung: vom Weinwettbewerb „Tage des Weines Nemčiňany“ in der Slowakei (2013–2016)

The possible influences of residual sugar content, color and ethanol content on sensory evaluation of wines were assessed. A set of 456 wine samples from the wine competition “Nemciňany Wine Days” (Slovakia) was selected for the study. Samples were analysed using by Fourier-transform infrared spectroscopy. For statistical data processing and testing ANOVA, LSD test, Student’s t‑test with significance level 0.05 were used. The wines were evaluated by 60 professional judges using the scale (100 point) of the International Union of Oenologists. The effect of the reducing sugar’s content on the wine score was confirmed. No statistically significant effect of the reducing sugar content on the sensory evaluation within the category semi-dry wines was confirmed. Wine color affects the sensory score. Significantly higher and more balanced sensory evaluation of red and rose wines compared to white wines was confirmed. Sensory score depending on ethanol content was statistically not significant.

Characteristic volatile compounds of Monastrell wines

Seventy-five percent of the red wines of the Protected Designation of Origin (PDO) Alicante are based on Monastrell grapes. The wine aroma is one of the most important characteristics linked to the quality and consumers’ preferences. Scopus database was used to gather information about the concentrations ranges of the main volatile compounds present in the Monastrell red wines, with their aromatic descriptions and their detection and/or recognition thresholds. Seventeen volatile compounds were identified as those having a significant contribution to this red wine aroma. However, it is important to indicate that there is a need to continue reviewing critically the threshold values (detection and/or recognition) of the main volatile compounds with a "potentially" significant contribution to the odor/aroma/flavor of the Monastrell wines. This information will be essential in preparing reference materials for trained sensory panels calibration for descriptive sensory evaluation of wines.

Sensory evaluation of wine through correspondence analysis: a theoretical and empirical rationale

ABSTRACTSensory evaluation in wine research focuses on understanding wine preference and choice within a holistic framework. This study offers a theoretical and empirical rationale for the sensory evaluation of wine. A precondition for sustainability and success in the market arena is a clear understanding of potential interaction of sensory evaluation properties and other factors affecting consumer choice. New approaches and methodologies for preference matching and assessment of sensory properties and information queues on overall liking are of fundamental importance for wine makers. The aim of this study is to advance the understanding of sensory evaluations affecting consumer both on empirical and theoretical grounds. For the implementation of this aim, an empirical research with real wine tasting data was conducted and analyzed through the use of Correspondence Analysis (CA). The findings of this study demonstrate that this method is more appropriate in wine sensory data analysis due to their categorical and non-parametric nature. CA is a very useful technique to establish a solid knowledge for the identification of the wines based on evidence and facts of their aromatic characteristics.

Proposal of the head-heart-base technique as an innovative method to describe and evaluate the aroma profile of wine and cider

ABSTRACTA novel method for the sensory evaluation of wine and cider is proposed that combines advantages of other commonly used techniques while simplifying a tasting protocol that is more accessible for unexperienced panelists. The method is based on panelist’s evaluation of samples in three discrete and directed steps; evaluation of head, heart, and base characters. The technique provides the sensory analyst with a simplified approach to difference testing and, in many instances, helps statistically differentiate samples by reducing panelist confusion. The head aroma is defined as the first impression after removing the lid from a covered glass prior to agitating the sample. The heart aroma is defined as the primary impression after agitating the sample. The base character is defined as the final aroma impression and retronasal evaluation of the product. Each component is evaluated independently using a generalized grouping of descriptors; sensory impression or grouping descriptors can be refined if the analyst aims to draw a higher level of detail or descriptive analysis from their panel. Application of the proposed analytical protocol suggests that the technique is simple for less-experienced panelists to learn and follow, and allowed them to easily focus on the testing attributes with minimal confusion of confounding factors.

A Novel Fuzzy Mathematical Method to the Sensory Evaluation of Wine

The aim of this study is to propose a new sensory evaluation method of wine. Sensory evaluation of wine contains four evaluating factors, which are color, aroma, taste and style. Sensory evaluation values given by experts are usually expressed with linguistic terms, which are more suitable depicted by triangular numbers than crisp numbers. The new evaluation method is developed with the concept of TOPSIS combining with fuzzy AHP method. The fuzzy AHP method is used to determine the weights of attributes and TOPSIS method is used to rank all the wine samples. An applied example is given to verify the new method and the result shows that the proposed method is effective and feasible.

Winter chill protection of grapevines by burial: evaluation of the crawled cordon training system

The objective of this work was to select a training system suitable for grapevines grown in areas where vine burial is practiced for protection against winter chill (especially as it is practised in the arid/semiarid areas of northern China). We evaluate the influence of a new training system crawled cordon training (CCT) and compare it with a traditional training system independent long-stem pruning (ILSP). The study considers fruit quality, sensory evaluation of wines and an analysis of labour practices at Rongchen Chateau in China during the years 2011, 2012 and 2013. During the first three years under CCT, average yield was 39.69 % lower than under ILSP but CCT showed higher yield stability. The ripeness of grapes under CCT was higher than under ILSP, so sensory evaluation of CCT wines was also higher. Moreover, CCT also reduced the labour involved for winter pruning, summer pruning and harvesting by 24.4 %, 25.0 % and 37.5 %, respectively. This study shows that under CCT grape quality, yield stability and wine quality were significantly higher than under ILSP, while labour inputs (costs) were significantly lower.

Effect of co‐inoculation with yeast and bacteria on chemical and sensory characteristics of commercial Cabernet Franc red wine from Switzerland

AbstractBACKGROUNDMalolactic fermentation (MLF) is a critical step in modern winemaking and the co‐inoculation of lactic acid bacteria with yeasts represents an emerging approach to improve the quality of wine. This study aims to evaluate the effect of inoculation timing on the chemical and sensory characteristics of two commercial Cabernet Franc wines: (i) a control wine in which MLF was inoculated after the completion of alcoholic fermentation (AF); and (ii) a co‐inoculated wine where simultaneous alcoholic and malolactic fermentations occurred.RESULTSBesides the expected full conversion of malic acid into lactic acid, the MLF with co‐inoculum of yeast/bacteria at initial AF allowed for reduced fermentation times, i.e. faster winemaking process. Although important changes in the chemical parameters of wines were found, especially color intensity and volatile compounds, there was a trend on the sensory evaluation of wines with a greater perception of red and ripe fruits in the case of co‐inoculation wine, while the control wine was dominated by notes of spice and herbs. The results of GC/MS analysis showed the largest differences for the 3‐hydroxy‐2‐butanone (acetoin, the reduced form of diacetyl) and isoamyl alcohol concentrations, the former was 3.2 times higher under co‐inoculum conditions, whereas the latter showed the opposite behavior.CONCLUSIONThe co‐inoculation protocol proposed is a valuable choice for innovative winemaking of Cabernet Franc wines, and results from a large‐scale winemaking process are provided for the first time. © 2015 Society of Chemical Industry

Effect of headspace volume, ascorbic acid and sulphur dioxide on oxidative status and sensory profile of Riesling wine

White wine spoilage due to oxidation is a major concern during post-fermentation treatments and bottling. In this study, we explored the effects of different oxygen and free SO2 levels and ascorbic acid addition on the development of white wine. Riesling wine was bottled in 500-mL bottles under screw caps with four different headspace volumes (0, 10, 20 and 30 mL), two levels of free SO2 (45 and 70 mg/L) and with and without ascorbic acid (250 mg/L) addition giving 16 wines for analysis. Cold stored (at 5 °C) control was used as reference for data analysis and sensory evaluation. Dissolved oxygen and the oxygen in headspace were measured in the resulting 17 wines. Free and total SO2 concentrations, ascorbic acid concentration, colour, redox potential and antioxidative capacity were measured regularly in wine samples. After 6 months of storage, the wines were evaluated using descriptive sensory analysis. Both sensory and analytical results showed significant differences among the wines. Intensive wine exposure to oxygen (headspace volume) affected colour, free and total SO2 rate, and the overall sensory quality of wine. Ascorbic acid addition had positive effect on the sensory evaluation of wines and on SO2 levels, whereas combined with large headspace volumes, provoked intensive browning in wine samples.

Relationship between wine scores and visible–near-infrared spectra of Australian red wines

Sensory analysis of wine involves the measurement, interpretation and understanding of human responses to the properties perceived by the senses such as sight, smell and taste. The sensory evaluation of wine is often carried out by wine judges, winemakers and technical staff, and allows characterization of the quality of the wine. However, this method is lengthy, expensive, and its results depend on panel training and the specific vocabulary used by the panel. A robust, rapid, unbiased and inexpensive method to assist in quality assessment purposes will therefore be beneficial for the modern wine industry. This study aims to investigate the relationship between sensory analysis, visible (VIS) and near-infrared (NIR) spectroscopy to assess sensory properties of commercial Australian wine varieties. For the purposes of this study 118 red wine samples (Cabernet Sauvignon, Shiraz, Pinot Noir, Tempranillo, Nebbiolo and blends) graded by a panel of experienced tasters and scored according to the Australian wine show system were scanned in transmission in the VIS and NIR range (400-2,500 nm). Partial least squares regression models were developed between the overall score given by the judges and the combined VIS-NIR spectra, using full cross validation (leave-one-out method). The results showed that NIR spectroscopy was able to predict wine quality scores in red wine samples (R = 0.61 and standard error of prediction of 0.81). The practical implication of this study is that instrumental methods such as VIS-NIR spectroscopy can be used to complement sensory analysis and can facilitate the task at early stages of product development, making high-throughput screening of novel products feasible or maintaining the consistency of the product.

Sensory Evaluation of Wine and Commercial Realities: Review of Current Practices and Perspectives

The attributes of a wine rely on the sensory acuity of the winemaker or the winemaker’s team. Depending on the winery operations or the style of wine made, the winemaker can be viewed as the expert crafting an artisan wine or producing a commercial alcoholic beverage designed to appeal to many consumers. The globalization of the wine market now enables more consumers to taste wines produced in foreign regions. Winemakers producing popular wines have been challenged by evolving consumer needs, values, and motivations for drinking wines, consumption habits, and greater product competition. This review discusses the tools sensory evaluation provides to assist winery operations by characterizing wine sensory properties and by better understanding consumer preferences in order to design better wine styles. By reviewing the scientific and marketing literature, key concepts are illustrated and new perspectives for consumer-driven winemaking and wine business strategies are proposed.

Composition and Quality of Juices and Wines of EightVitis RotundifoliaMichx. Cultivars

The composition and quality of muscadine grape juices and wines of three bronze (Carlos, Magnolia and Summit) and five purple (Noble, Regale, Tarheel, NC 94-4 and NC 154-2) cultivars were assessed over a two-year period. The grapes were grown in 1975 and 1976 in the experimental vineyard at the Delta Branch of the Mississippi Agricultural and Forestry Experiment Station located at Stoneville, Mississippi. The composition of juices was typical of grapes grown in hot, humid climates. The soluble solids ranged from 12.8 to 19.8°Brix for the two-year period. Total acid content varied chiefly with cultivar, and to a lesser extent with the year of harvest; for example, in 1975 the acid content ranged from 0.34 to 0.83% and in 1976 from 0.38 to 0.88%. Tannins, as expected, were about twice as high in juices of red grapes as in those of bronze grapes, although their respective concentrations were generally within the limits reported for bunch grapes (0.0 to 0.2%). Six cations (Ca, Mg, K, Na, Mn and Zn) occurred chiefly in the non-solid portion of juices while Fe and Cu were found mainly in the solid fraction of juices. Wines had an average pH of 3.22 and contained 0.71% total acid, 37 mg/100 mL volatile acid, 0.68% fixed acids, 11.9% ethanol by volume, and 46 mg/100 mL methanol. The total phenol content was about three times higher in red wines than in white wines. Tristimulus color description of white wines showed that they had a natural light golden color with little or no variation among cultivars. The combined means of their L values for 1975 and 1976 were 96.98, 96.38 and 95.28 for Magnolia, Carlos and Summit, respectively. Out of the five red wines, Tarheel and Noble displayed the most desirable tristimulus color characteristics. Their mean L values were 39.26 (Tarheel), and 42.22 (Noble) and their saturation values were 4.55 and 19.20, respectively. For all red wines the color description ranged from light red (NC 94-4) to dark blue-red (Tarheel). Sensory evaluation of wines was conducted by the paired comparison preference test. The paired comparison test showed that wines with higher residual sugar contents were preferred by the majority of panelists.

Pin-Mill and Roller Crushers Compared. 3. Sensory Evaluation of Wines

Dry table wines produced by a pin-mill crusher in three consecutive vintages were compared with equivalent roller-crusher wines. The bouquet of white wines was better in the pin-mill samples, and further improved with skin contact time prior to fermentation. Red wine quality was also enhanced, though to a limited degree. No significant preference for roller-crusher wines was recorded.

Pin-Mill and Roller Crushers Compared. 3. Sensory Evaluation of Wines

Dry table wines produced by a pin-mill crusher in three consecutive vintages were compared with equivalent roller-crusher wines. The bouquet of white wines was better in the pin-mill samples, and further improved with skin contact time prior to fermentation. Red wine quality was also enhanced, though to a limited degree. No significant preference for roller-crusher wines was recorded.