Wine Sensory Profile Research Articles

Influence of Technological Operations in the Dissolved Oxygen Content of Wines

Oxygen plays a crucial role in oenology. The oxygen leads to changes in the chemical and sensory profile of wines. On one hand, the impact of moderate oxygen exposure of red wine has a positive effect in its colour, aromatic bouquet and mouth-feel properties. On the other hand, oxygen has a negative effect on white wine's quality, as well as the sensory and compositional levels. The purpose of this study was to quantify the dissolved oxygen in red and white wine, during different cellar operations such as racking, tartaric stabilization, filtering and bottling. The techniques that contribute most to the enrichment of oxygen in wine are: cold tartaric stabilization (2.29 mg/L, white wines), bottling (1.38 mg/L red wines and 1.11 mg/L white wines) and bag-in-box filling (2.47 mg/L red wines; 2.22 mg/L white wines). After identifying the most critical technical operations in wine making, preventive and corrective measures had to be taken to reduce the dissolved oxygen content of wines, as well as preventing their depreciation.

Sequential inoculation versus co-inoculation in Cabernet Franc wine fermentation

A study has been carried out in order to determine the effect of the lactic acid bacteria inoculation time on the kinetic of vinification and on chemical and sensory characteristics of Cabernet Franc wines. Traditional vinifications, with lactic acid bacteria inoculated after completion of alcoholic fermentation were compared with vinifications where yeast and bacteria were co-inoculated at the beginning of vinification. One commercial yeast strain and an autochthonous Oenococcus oeni strain (C22L9), previously identified and selected at our laboratory, were used. Monitoring of alcoholic and malolactic fermentations was carried out by yeast and lactic acid bacteria counts and by measuring l-malic acid concentration. Wines were chemically characterized and analysed for volatile compounds content. A sensory analysis, consisting of a descriptive and a triangular test, was also carried out. Results from this study showed that the concurrent yeast/bacteria inoculation of musts at the beginning of vinification produced a reduction in duration of the process without an excessive increase in volatile acidity. Differences in volatile compounds content and the corresponding impact on the sensorial profile of wines were also displayed. These results suggest that co-inoculation is a worthwhile alternative for winemaking of Cabernet Franc wines, if compared with traditional post-alcoholic fermentation lactic acid bacteria inoculation.

Irrigation effects on the sensory perception of wines from three white grapevine cultivars traditional from Galicia (Albariño, Godello and Treixadura)

This study aimed to assess the effect of irrigation on the sensory profile of wines from three Galician white grapevine cultivars. Field experiments were carried out in 2011 and 2012 at the research farm of the Estación de Viticultura e Enoloxía de Galicia (EVEGA), where two treatments were imposed: rain-fed and irrigation to the 50% of potential evapotranspiration. A panel of seven judges tasted the wines in six sessions (one per cultivar and year) for evaluating their sensory profile. In the case of ‘Albariño’, three descriptors, although not the same for both years, were significantly different between treatments. For ‘Godello’, several descriptors differed between treatments, and citric was present in both years. In ‘Treixadura’ white fruit and persistence were present in 2011 and 2012. Several descriptors contributed to the hedonic index, but differed between wines; however, balance was common for all the cultivars and years. In conclusion, ‘Albariño’ and ‘Godello’ wines from the rain-fed treatment received higher marks than those from the irrigation treatment; whereas Treixadura wines from the irrigation treatment were better valued.

The Effect of Reduced Alcohol on the Sensory Profiles and Consumer Preferences of White Wine

AbstractDealcoholization, the removal of alcohol from wine, is a technique used to combat rising alcohol levels in wine. However, little is known about how changes in alcohol levels affect wine sensory composition. The aim of the study was to investigate the influence of dealcoholization on wine sensory profiles using trained panelists and consumers. A portion of a Californian Chardonnay was dealcoholized and blended back to the original wine at 0.2%v/v increments up to 2%v/v reduction. From a descriptive sensory analysis, with a minimum alcohol difference of 0.4%v/v, wines differed (P ≤ 0.05) in overall aroma intensity and hot mouthfeel, which were positively correlated with alcohol. Unlike panelists, consumers were unable to detect changes among wines with a 1%v/v difference. These results suggest that a moderate reduction of alcohol in oaked Chardonnay wines has a minimal impact on sensory composition and consumer preferences.Practical ImplicationsThis work suggests that reducing the alcohol levels of oaked white wine using dealcoholization techniques results in minimal perceptible changes to the sensory profile. Alcohol reduction technology is of beneficial use to the wine industry. It would be advantageous for wine producers and consumers to be better informed, regarding the financial, social and health benefits of partially dealcoholized wine, without reduction in wine quality.

Effect of different irrigation strategies on vine physiology, yield, grape composition and sensory profile of Sauvignon Blanc (<em>Vitis vinifera</em> L.) in a cool climate area

<p style="text-align: justify;"><strong>Aim</strong>: The impacts of partial root zone drying (PRD) and regulated deficit irrigation (RDI) on soil moisture, vine water status, yield components, fruit composition and wine sensory profile of Sauvignon blanc were studied in a cool climate region.</p><p style="text-align: justify;"><strong>Methods and results</strong>: Field experiments were conducted in a commercial Sauvignon blanc block in Ontario, Canada between 2006 and 2008. Treatments were: non-irrigated control, PRD, full irrigation [100% of crop evapotranspiration (ET<sub>c</sub>)] and one level of RDI (25% ET<sub>c</sub>). Treatments began immediately after fruit set and continued until the beginning of September. Reference evapotranspiration (ET<sub>o</sub>) was calculated using the Penman–Monteith equation. Soil moisture and vine water status (leaf water potential and transpiration rate) in the PRD treatments were generally less than in 100% ET<sub>c</sub> but higher than in non-irrigated and 25% ET<sub>c</sub> treatments. Almost all treatments were different than non-irrigated vines in fruit composition and wine sensory attributes. RDI strategies were more consistent across vintages than the PRD treatments in their effect on vine water status, grape composition and sensory profiles.</p><p style="text-align: justify;"><strong>Conclusions</strong>: Use of RDI or PRD in cool climates during dry and warm years can improve grape composition. In very dry and hot seasons, like that of 2007, irrigation improved grape composition and wine aroma typicity. RDI enhanced fruity aroma attributes, which suggests that this could be a viable strategy to improve grape and wine quality in cool areas. However, due to high climatic variation over the period studied, no consistent pattern of irrigation effects was found for berry composition, suggesting that plant water status was not the only factor that controlled fruit and wine quality.</p><p style="text-align: justify;"><strong>Significance and impact of the study</strong>: To the best of our knowledge, this study is the first evaluation of PRD in a cool, humid climate, and highlights the potential value of both RDI and PRD irrigation techniques in cool climate regions, particularly during dry growing seasons.</p>

Wickerhamomyces anomalus AS1: a new strain with potential to improve wine aroma

The monoterpenes are the most important contribution to the olfactory profile of wine due to their low odour threshold. These and other aroma-active substances do not generally exist in a free form but are conjugated to mono- or disaccharides, thereby forming water-soluble and odourless complexes. Enzymes that cleave the sugar moieties from the precursors can, therefore, have a major impact on the sensory profile of wine, as they release the volatile aroma compounds. For this reason, we searched for wine yeasts producing glycosidases which are active under oenological conditions. A collection of 100 wine yeasts were screened for glycosidase activities in whole cells and in culture supernatants. Kinetic parameters were determined spectrophotometrically with synthetic model substrates, and hydrolysis of natural glycosides was detected by thin-layer chromatography. A yeast isolate, AS1, was identified as a new Wickerhamomyces anomalus strain which hydrolysed a number of synthetic and natural glycosides under oenological conditions. Citronellol- and nerol-glucosides, among the most frequently occurring aroma precursors in wine, were also cleaved. In contrast to a commercial β-glucosidase, whole cells of W. anomalus AS1 catalysed deglycosylation of arbutin and salicin directly in a white and a red wine. Besides the formation of intra- and extracellular glucoside hydrolases, strain AS1 exhibited arabinosidase and xylosidase activities which are also essential for the release of flavour compounds. Even with limited functionality at oenological conditions, the glycoside hydrolase activities of W. anomalus AS1 may improve aroma development, provided that the reaction occurs over a longer period, as it is the case during wine-making.

Characterizing the Chemical and Sensory Profiles of United States Cabernet Sauvignon Wines and Blends

Cabernet Sauvignon is one of the most reputable red grape varieties grown in the United States; however, limited information is available on the chemical and sensory composition of the resulting wines. The purpose of this study was to develop a rapid, targeted profiling method for measuring volatile compounds with sensory impact in U.S. Cabernet Sauvignon wines and blends. We developed a semiquantitative, automated headspace solid-phase microextraction (HS-SPME) gas chromatography–mass spectrometry (GC-MS) method combined with synchronous selected ion monitoring (SIM)/scan detection to measure 61 volatile compounds. The compounds monitored included grape-derived norisoprenoids and terpenes; fermentation-derived esters, higher alcohols, and aldehydes; Brettanomyces-related compounds; and oak-derived compounds. Methoxypyrazine was also measured using HS-SPME-GC-MS/MS. Twenty-four commercial U.S. Cabernet Sauvignon varietal and blended wines from several regions in California and Washington State were selected to encompass a broad range of wine styles and were analyzed using the GC methods developed. The results were compared to a descriptive sensory analysis of the wines using 11 trained assessors to determine the extent to which the chemical analyses could predict sensory profiles. The rapid, targeted profiling method was able to predict a number of aroma sensory descriptors. The Cabernet Sauvignon wines and blends differed in their chemical and sensory profiles and were differentiated, in part, as a result of the direct and indirect influences of varying alcohol levels. This work provides the wine industry with the ability to rapidly assess wine volatile composition in order to further elucidate the relationships between the chemical compounds and sensory profiles of wines.

The influence of alcohol on the sensory perception of red wines

Over the last 20years, wine alcohol concentrations have been steadily increasing worldwide. Despite this, few studies have investigated how alcohol influences wine perception during sensory analyses. The aim of the study was to investigate whether tasting order affects perception of wines with varying levels of alcohol. The sensory profiles of commercial Cabernet Sauvignon wines ranging from 12% v/v to 16% v/v were characterized using three tasting orders: randomized (Random), high alcohol wines (greater than 14% v/v) before low alcohol wines (less than 14% v/v) (Hi-Lo) in each session, and the inverse (Lo-Hi), in both descriptive sensory analysis and wine competition conditions.The order of wine assessment based on alcohol concentration significantly influenced sensory perception, particularly on the palate. In some instances, the two specified tasting orders showed opposing effects of alcohol on wine sensory profiles, whereas the Random group had mostly intermediary responses. The largest differences occurred when low alcohol wines were tasted first, with substantial changes in the sensory profiles of high alcohol wines.The results of the study demonstrate the importance of alcohol concentrations on red wine perception in sensory analyses and suggest the need to consider wine alcohol concentrations when professionally assessing wine quality, such as wine competitions or wine reviews.

Influence of inoculation time of an autochthonous selected malolactic bacterium on volatile and sensory profile of Tempranillo and Merlot wines

A study was carried out to determine the effect of the inoculation time of the lactic acid bacteria (LAB) on the kinetic of vinification and on chemical and sensory characteristics of Tempranillo and Merlot wines. Traditional vinifications, with LAB inoculated after completion of AF, were compared with vinifications where yeast and bacteria were co-inoculated. Two commercial yeast strains and an autochthonous Oenococcus oeni strain (C22L9) previously identified and selected at our laboratory were used. Monitoring of alcoholic and malolactic fermentations was carried out by yeast and lactic acid bacteria counts and by measuring contents of glucose+fructose, malic acid and lactic acid. The implantation rate of O. oeni C22L9 was calculated by typing isolates obtained from count plates using the RAPD-PCR (Randomly Amplified Polymorphic DNA-Polymerase Chain Reaction) technique. Wines were chemically characterised and analysed for biogenic amine and volatile compound contents. A sensory analysis, consisting in a descriptive and a triangular test was also carried out. Results from this study showed that for both grape varieties, the concurrent yeast/bacteria inoculation of musts produced a significant reduction in duration of the process, without a pronounced degradation of malic acid during AF, nor an excessive increase in volatile acidity. Biogenic amine content was also lower in wines produced by co-inoculation. Important differences in volatile compound contents were observed, although there was little impact on the sensorial profile of wines. These results suggest that co-inoculation using O. oeni C22L9 is a worthwhile alternative compared to traditional post AF inoculation for Tempranillo and Merlot winemaking.

Comparison of inorganic and organic nitrogen supplementation of grape juice – Effect on volatile composition and aroma profile of a Chardonnay wine fermented with Saccharomyces cerevisiae yeast

Inorganic nitrogen salts, and to a growing extent organic nitrogen preparations, are widely used to ameliorate a nitrogen deficiency in wine fermentation, but the impact of nitrogen supplementation on perceived wine sensory profile is essentially unknown. Supplementation of a low nitrogen Chardonnay grape juice with either ammonium nitrogen or combined amino acid and ammonium nitrogen showed that the type of nitrogen and concentration in the range 160–480mgN/l had a substantial impact on the formation of yeast volatile compounds and perceived wine aroma. Addition of amino acid and ammonium nitrogen increased both acetate and medium chain fatty acid esters to a greater extent and decreased higher alcohols to a lesser extent than ammonium nitrogen alone whereas ammonium nitrogen substantially increased ethyl acetate and acetic acid. Low nitrogen wines were rated relatively low in floral/fruity aroma descriptors, while moderate nitrogen wines showed a good balance between desirable and less desirable attributes, whereas high nitrogen produced either an acetic/solvent character or highest ratings for floral/fruity attributes, depending on nitrogen type. These results show that amount and type of nitrogen supplement can substantially modulate Chardonnay wine volatiles composition and perceived aroma.

Yeast strain effect on the concentration of major volatile compounds and sensory profile of wines from Vitis vinifera var. Treixadura

The fermentative ability of five Saccharomyces cerevisiae strains and their influence on the aroma and sensory properties of wine from Treixadura were evaluated to determine the most suitable yeast that produces a high quality wine from this grapevine variety. The results indicated that all strains, except T2, were able to lead the vinification process and have good fermentative powers. The chemical composition of wines obtained with resident cellar yeasts consisted of a significant amount of glycerol, a compound that contributes to the structure and smoothness in taste of the wine. In addition, these strains were good producers of acetates, ethyl esters and fatty acids, compounds that positively influence wine aroma. Compounds with a direct contribution to the aroma of Treixadura wines (Odour Activity Value >1) included 2-methyl-1-butanol, 3-methyl-1-butanol, 2-phenylethanol, isoamyl and ethyl acetate and the ethyl esters, ethyl butyrate, ethyl hexanoate, ethyl octanoate and ethyl decanoate. Sensory analysis supported the fact that cellar strains produced more fruity and floral wines than commercial or spontaneous fermentations. We conclude that resident cellar yeasts enhanced sensory quality of wines from Treixadura.

SENSORY ANALYSIS OF RED WINES: DISCRIMINATION BY ADAPTIVE FUZZY PARTITION

ABSTRACT Classification models were established on a set of sensory profiles associated with red wine samples bottled from three vintages. These profiles were defined by eight assessors charged, for all wine samples, to assign to each of 17 sensory descriptors a note ranged from 1.0 to 9.0, with two assessments for each judge. A new and innovative method called adaptive fuzzy partition (AFP), derived from fuzzy logic (FL) concepts, was tested on the same data set. FL is particularly suitable to classify sensory analysis data sets, as it can represent the “fuzziness” linked to an expert's subjectivity in the characterization of wine sensory profiles. More precisely, after subdividing the 48 sensory profiles into training and test sets, the AFP method predicted correctly 75% of the test assessments. These very encouraging preliminary results show the proposed methods are worth investigating more thoroughly, testing large and diverse wine data sets. PRACTICAL APPLICATIONSA new and innovative method called adaptive fuzzy partition, derived from fuzzy logic (FL) concepts, is presented. FL is particularly suitable to classify sensory analysis data sets, as it can represent the “fuzziness” linked to an expert's subjectivity in the characterization of wine sensory profiles.

Magnitude and Interaction of Viticultural and Enological Effects. I. Impact of Canopy Management and Yeast Strain on Sensory and Chemical Composition of Chardonnay Musqué

Chardonnay Musqué vines in Ontario were subjected to hedging (control), basal leaf removal (BLR), or cluster thinning (CT) over a 3-year period. Musts from each treatment were combined in a factorial treatment arrangement with yeast strains VL1, EC1118, and EC1118 + enzyme preparation AR2000. Yield was reduced by 21 to 36% by CT as a result of cluster removal. Fruit maturity was advanced by BLR and CT in reduced berry, must, and wine titratable acidity (TA); increased berry and must pH and Brix; increased must and wine free volatile terpenes (FVT) (CT only); and increased berry, must, and wine potentially volatile terpenes (PVT). VL1 wines were lower in pH and both FVT and PVT (1 of 3 years) than those of EC1118 and had higher TA (1 of 3 years). EC1118 + AR2000 wines did not differ from wines produced solely with EC1118 in terms of TA and FVT but were higher in PVT and pH. CT wines differed from BLR and control wines sensorially, with increased depth of color, higher sweetness and herbaceous/grassy aroma, and reduced tropical fruit aroma. BLR wines had higher tropical fruit and floral aromas, while control wines had greater acidity. Principal component analysis of sensory data suggested that variation in wine sensory profiles was due to both viticultural and enological practices.

Oxidation of Wine Phenolics: A Critical Evaluation and Hypotheses

Oxidation reactions involving phenolics might change the chemical and sensory profile of wines. While oxidation is a long-standing problem in winemaking, a definitive understanding of its chemical mechanisms is lacking, and such an understanding could allow us to better predict and control wine aging. We briefly summarize and discuss the current knowledge on the chemistry of wine phenolic oxidation and propose, along with other researchers, a new, comprehensive scheme in which the Fenton reaction and hydroxyl radicals have an essential role. This hypothesis suggests that catalytic iron converts wine’s hydrogen peroxide into hydroxyl radical. This leads to a much stronger and less selective oxidant that could react with almost all wine components, in proportion to their concentration and with little selectivity for antioxidant properties. This reaction could produce many electrophilic oxidation products, mainly aldehydes and ketones, that could further modify the chemical composition and sensory perception of wine. While the brevity of this report precludes a full review of oxidation, our aim is to stimulate more study and debate on the mechanisms in wine oxidation chemistry.

Sensory Effects of Consuming Cheese Prior to Evaluating Red Wine Flavor

The aim of this study was to assess, through descriptive analysis, the way in which the flavor perception of red wine was influenced by the wine pairing with a variety of cheeses. A panel of 11 trained judges evaluated the flavor of eight wines of four different varieties (Cabernet Sauvignon, Merlot, Pinot noir, and Syrah) before and after tasting cheese. Eight cheeses were selected: two soft (Mozzarella and Teleme), two medium-hard (Cheddars from Vermont and New York), two hard (Emmental and Gruyère), and two blue (Gorgonzola and Stilton). The results obtained by descriptive analysis showed that the cheese had significant effects on red wine flavor. Some attributes, such as astringency, bell pepper, and oak flavor, significantly decreased when the wine was evaluated after tasting cheese. Only butter aroma was significantly enhanced by cheese. It was also found that there was no significant wine-cheese interaction effect; in other words, the effect of any given cheese is equivalent for all wines. Although there were significant effects, the overall sensory profiles of wines without prior cheese tasting and as affected by cheese were very similar.