Experimental Wines Research Articles

Impact of vine water status on sensory attributes of Cabernet Franc wines in the Niagara Peninsula of Ontario

<p style="text-align: justify;"><strong>Aim</strong>: To examine the impact of vine water status on sensory and chemical characteristics of Cabernet franc wines on non-irrigated sites in the Niagara Peninsula, Ontario, to assess whether vine water status might be a key factor in the determination of so-called terroir effects.</p><p style="text-align: justify;"><strong>Methods and results</strong>: The effects of vine water status on wine sensory characteristics were studied in <em>Vitis vinifera</em> L cv. Cabernet franc in the Niagara Peninsula (Ontario, Canada) in the 2005 and 2006 vintages. Vine water status was monitored throughout the growing season in ten vineyard blocks using midday leaf water potential (Ψ) values. Chemical and descriptive sensory analyses were performed on nine (2005) and eight (2006) pairs of experimental wines to elucidate differences between wines from high and low water status (HWS, LWS) zones in each vineyard. Twelve trained judges evaluated six aroma, six flavor and three mouthfeel/taste sensory attributes, as well as color intensity. In 2005, LWS wines had higher color intensity (four sites), black cherry flavor (one site), and red fruit aroma and flavor (two sites). Similar trends were observed in the 2006 vintage. No differences were found from one year to the next between the wines produced from the same vineyard, despite markedly different conditions in the 2005 and 2006 vintages.</p><p style="text-align: justify;"><strong>Conclusions</strong>: Measurement of midday leaf Ψ was successful in detecting differences among vine water status levels throughout the growing season. The range of leaf Ψ values were almost consistent at most sites in both 2005 and 2006 years. Differences in vine water status resulted in wines with different composition, aroma, flavor, and color intensity. Despite two different vintages of hot and dry (2005) and wet (2006) seasons, similar trends were observed in high and low water status wines.</p><p style="text-align: justify;"><strong>Significance and impact of study</strong>: The strong relationships between leaf Ψ and sensory attributes of Cabernet franc suggest that vine water status is a major basis for the terroir effect.</p>

Characterization, antigenicity and detection of fish gelatine and isinglass used as processing aids in wines

Fish gelatine (FG) and isinglass (IG) are widely used in the pharmaceutical industry and as ingredients or processing aids in food production. Both products are the focus of interest since several countries, particularly the member states of the EU and Japan, USA, Australia and New Zealand, have introduced special labelling regulations for allergenic foodstuffs, such as fish and products thereof. Thus, there is a demand for a reliable and sensitive method for the detection of FG and IG in foodstuffs. In this study, the characterization of various FGs and IGs, polyclonal antibodies raised against fish collagen and the development of a sensitive indirect ELISA for the detection of FG and IG is described. The ELISA method detected ≤0.11 µg ml−1 from all FGs and IGs tested. The indirect ELISA was applied to various experimental wines where FG and IG had been used as processing aids and to several commercial wines. No residues of FG and IG were detected in the experimental wines additionally treated with bentonite, a strong adsorbent for proteins, and successive filtration. Additionally, no residues were found in the commercial wines. However, amounts of up to 0.33 µg ml−1 were found in some experimental wines not treated with bentonite and successive filtration. Therefore, wines may contain traces of FG and IG that were used as processing aids during wine production. However, treatment with bentonite in combination with additional filtration had a clear impact on these residues.

Feature extraction and selection from volatile compounds for analytical classification of Chinese red wines from different varieties

This work was undertaken to evaluate whether it is possible to determine the variety of a Chinese wine on the basis of its volatile compounds, and to investigate if discrimination models could be developed with the experimental wines that could be used for the commercial ones. A headspace solid-phase microextraction gas chromatographic (HS-SPME-GC) procedure was used to determine the volatile compounds and a blind analysis based on Ac/Ais (peak area of volatile compound/peak area of internal standard) was carried out for statistical purposes. One way analysis of variance (ANOVA), principal component analysis (PCA) and stepwise linear discriminant analysis (SLDA) were used to process data and to develop discriminant models. Only 11 peaks enabled to differentiate and classify the experimental wines. SLDA allowed 100% recognition ability for three grape varieties, 100% prediction ability for Cabernet Sauvignon and Cabernet Gernischt wines, but only 92.31% for Merlot wines. A more valid and robust way was to use the PCA scores to do the discriminant analysis. When we performed SLDA this way, 100% recognition ability and 100% prediction ability were obtained. At last, 11 peaks which selected by SLDA from raw analysis set had been identified. When we demonstrated the models using commercial wines, the models showed 100% recognition ability for the wines collected directly from winery and without ageing, but only 65% for the others. Therefore, the varietal factor was currently discredited as a differentiating parameter for commercial wines in China. Nevertheless, this method could be applied as a screening tool and as a complement to other methods for grape base liquors which do not need ageing and blending procedures.

Determination of the Bovine Food Allergen Casein in White Wines by Quantitative Indirect ELISA, SDS−PAGE, Western Blot and Immunostaining

This study describes the characterization of allergic bovine casein and caseinate fining agents by SDS-PAGE analysis and the development of a quantitative indirect ELISA for the detection of these substances in wines. The ELISA was applied to various experimental wines that were treated with different caseinate dosages and went through different processing steps and to a panel of commercial wines. Positive results were assured by SDS-PAGE, Western blot, and immunostaining. Comprehensive literature research was done to evaluate the demanded sensitivity of the ELISA. The results showed that alpha- and beta-caseins remain in some wines and are detectable. Estimated amounts were in the range or below an estimated no-observed adverse effect level (NOAEL) of 0.9 mg/L, but it was concluded that there is still an uncertainty about this NOAEL. Additional applied processing, referring to bentonite treatment and successive filtration, was determined to contribute to a significant decrease of casein residues in wines.

SPME–GC method as a tool to differentiate VOC profiles in Saccharomyces cerevisiae wine yeasts

The aim of this work was to study the variability of 36 Saccharomyces cerevisiae wild strains isolated from different grape varieties and from two very distant zones, located in Northern and Southern Italy. The strains were differentiated on the basis of parameters of technological interest, such as resistance to antimicrobial compounds frequently present in wine, and the production of volatile aromatic compounds (VOC), determined by SPME procedure in the experimental wines obtained by inoculated fermentations. The VOC profile allowed to differentiate the yeasts in function of isolation area: S. cerevisiae isolated from Southern Italy grapes were able to produce more volatile compounds than those from Northern Italy. The compounds synthesized by all the yeasts, besides the ethanol, were 3-methyl-1-butanol and ethyl acetate. The production of acids during the alcoholic fermentation was a characteristic of Southern yeast strains. The screening of S. cerevisiae strains for technological parameters, such as sulphur dioxide, copper and ethanol resistance or hydrogen sulphide production, revealed similar behaviour for sulphur dioxide resistance among Northern and Southern S. cerevisiae strains. Copper resistance and sulphur dioxide production were correlated to isolation area: S. cerevisiae “Northern” strains showed higher copper resistance and lowest hydrogen sulphide production than that exhibited from “Southern” strains.

Effect of juice clarification by flotation on the quality of white wine and orange juice and drink - Short Communication

White wines of Debina cultivar were made from musts clarified by flotation using nitrogen as foaming agent. Flotation using air as the foaming agent (must hyperoxidation), without SO<sub>2</sub> addition, was also applied. Turbidity and suspended solids were lower in must clarified by flotation using nitrogen than in that clarified by sedimentation (control). Flotation with hyperoxidation led to a reduction of must phenolics. All experimental wines exhibited similar gross compositions (alcohol, reducing sugars, total acidity, and volatile acidity). Wines made from musts clarified by flotation using nitrogen had similar total phenolic content, browning capacity, and organoleptic quality as the control wines. Wines made from musts clarified by flotation using air had lower total phenolic contents and browning capacity than were those in control wines. These wines were of well acceptable quality but exhibited a slightly oxidised aftertaste. The results indicate that flotation using nitrogen can be effective in the production of typical Debina wine, while flotation using air may be useful in that of table wine without SO<sub>2</sub> addition. Orange juice was clarified by flotation using nitrogen or air as the foaming agent. Orange juice clarified by flotation using nitrogen as the foaming agent exhibited lower turbidity and a similar pulp content to that clarified by centrifugal separator (control). It had an acceptable taste and aroma. Juice clarified by flotation using air as the foaming agent, along with pectolytic enzyme treatment, exhibited much lower turbidity and pulp content compared to control. The clear juice had an acceptable taste but no aroma. The fermented clear juice was averagely rated, exhibiting a pleasant aroma and only a slightly bitter taste. The results indicate that flotation using nitrogen can be effective in the production of natural orange juice, while flotation using air may be useful in the production of orange drink.

Biodiversity of wild strains of Saccharomyces cerevisiae as tool to complement and optimize wine quality

The principal agent in winemaking is the yeast Saccharomyces cerevisiae, which is characterized by a significant strain biodiversity. Here we report the characterization of 80 wild S. cerevisiae strains, isolated from grapes of different varieties in southern Italy, for genetic and technological variability. By PCR amplification with M13 primer a significant polymorphism was recorded and 12 different biotypes were identified among the strains. The specific strain-pattern could be used to follow the dynamics of different biotypes during the fermentation process. The analysis of experimental wines obtained by inoculated fermentations with the 80 strains showed significant differences among the wines. The level of each compound was a function of the strain performing the fermentative process. The main variables for the strain differentiation were the production of acetaldehyde and acetic acid, which ranged from 53 to 282 mg/l and from 0.20 to 1.88 g/l, respectively. Selected strains were tested in fermentation with two different grape musts, yielding experimental wines differing in the levels of secondary compounds and polyphenol content, in function of the interaction “grape must composition/yeast strain”. This finding has an applicative value for the potentiality of utilizing the resource of strain variability as a tool to individuate suitable starter cultures, which are able to complement and optimize grape quality.

Prediction of Wine Color Attributes from the Phenolic Profiles of Red Grapes (Vitis vinifera)

Knowledge about the relation between grape and wine phenolics is of key interest for the wine industry with respect to being able to predict wine quality from analyses of grapes. Prediction of the phenolic composition and color of experimentally produced red wines from the detailed phenolic composition of the corresponding grapes was investigated using a multivariate approach. Grape extracts and wines were produced from 55 different grape samples, covering 8 different Vitis vinifera cultivars: Alicante, Merlot, Syrah, Cinsault, Grenache, Carignan, Cabernet Sauvignon, and Mourvedre. The phenolic composition of the grapes and wines showed that the average ratios between wine and grape phenolics ranged from 0.25 to 7.9 for the different phenolic compounds. Most interestingly, the average ratios were low for anthocyanins (0.31) and tannins (0.32), intermediate for (+)-catechin (0.75) and polymeric pigments (0.98), and high for gallic acid (7.9). Individual wine phenolics in general correlated well with several grape phenolics, indicating that a multivariate approach might be advantageous for prediction of wine phenolics from grape phenolics analysis. However the use of multivariate prediction of individual wine phenolics from the complete grape phenolic composition only improved the prediction of wine polymeric pigments, whereas wine anthocyanins were predicted with the same precision as from the direct relation with grape anthocyanins. Prediction of color attributes of pH normalized experimental wines from the phenolic profiles of grapes was accomplished using a multivariate approach. The correlation between predicted and measured total wine color was high ( r = 0.958) but was very similar to the correlation coefficient obtained for the direct relation between grape anthocyanins and total wine color ( r = 0.961). Color due to copigmentation, color due to anthocyanins, and color intensity were also predicted well.

A charming little Cabernet

PurposeThe purpose of this research is to examine the impact of brand personality on purchase intent and the influence of three design elements of wine labels on brand personality.Design/methodology/approachParticipants made brand personality judgments and rated their purchase intent for subsets of 90 experimental wine labels, which varied along the dimensions of color, illustration, and design layout.FindingsBrand personality explained nearly half of the variance in purchase intent, with the facets successful, charming, spirited, and up‐to‐date being most strongly correlated with purchase intent. Of the three dimensions of visual design studied, the illustration used on the label had the greatest impact on both purchase intent and perceptions of brand personality.Research limitations/implicationsThis study used a proxy to measure purchase intent and studied only a subset of brand personality facets, limiting the generality of findings.Practical implicationsThis research offers brand managers a potential means of evaluating prospective designs in terms of their likely impact on purchase intent and consumer perceptions of brand personality, and suggests general guidelines for the design of product line extensions from a successful label design.Originality/valueThis research helps brand managers and packaging designers to leverage brand personality research and evaluate the effectiveness of new designs.

Formation of Hydroxyphenyl-pyranoanthocyanins in Grenache Wines: Precursor Levels and Evolution during Aging

Grenache red wines were produced following three different winemaking techniques, that is, small-scale standard experimental wines and industrial-scale wines by both double-mash fermentation and fermentation in Ganimede vats. Wines were analyzed for their color properties, as well as the anthocyanin, flavonol, hydroxycinnamic acid, and pyranoanthocyanin profiles following alcoholic and malolactic fermentation. The evolution of pyranoanthocyanins and their corresponding precursors in the experimental wines was monitored at 6 and 10 months of aging. Wines produced by double-mash fermentation exhibited superior color properties compared to Ganimede wines and the experimental red wines, due to better extraction of flavonols and anthocyanins as well as a lower degree of polymerization. Pyranoanthocyanin formation varied within the different classes of pigments. Vitisins A and B were formed only during alcoholic fermentation. Pinotin A (i.e., the reaction product from malvidin 3-glucoside and caffeic acid) formation took place only during the aging process, whereas formation of hydroxyphenyl-pyranoanthocyanins derived from p-coumaric and ferulic acid followed two different pathways, that is, an enzymatically assisted production during fermentation and a pure chemical formation during aging.

Differentiation of Young Red Wines Based on Chemometrics of Minor Polyphenolic Constituents

For reasons of examining any possible discrimination of young red wines based on selected, minor polyphenols, a survey was carried out including 35 samples originating from three Hellenic native and three international Vitis vinifera cultivars from various regions of Greece. All samples were experimental wines vinified and stored under identical conditions, in an effort to minimize the effect of different winemaking technologies as well as aging. The polyphenols analyzed belonged to two categories: benzoic acid derivatives, including gallic acid, protocatechuic acid, vanillic acid, and syringic acid, and stilbenes, including astringin, piceid, and resveratrol (all trans isomers). Data handling employing discriminant analysis (DA) yielded very satisfactory categorization of samples in terms of both cultivar and geographical region of origin. This outcome was discussed with regard to the value of certain minor polyphenols that could serve as characteristic indices for discrimination of varietal red wines, after appropriate implementation of chemometrics.

Occurrence and Significance of Quercitol and Other Inositols in Wines during Oak Wood Aging

Inositols (quercitol, <i>chiro</i>-inositol, <i>scyllo</i>-inositol, and <i>myo</i>-inositol) were analyzed in commercial wines, in samples of experimental wines, in wines aged in oak barrels from different origins and with different time of usage, and in oak chip-treated wines. <i>chiro</i>-Inositol and quercitol were documented for the first time in wine. <i>chiro</i>-Inositol seemed to be a component arising from grapes, together with other cyclitols such as <i>myo</i>-inositol and <i>scyllo</i>-inositol, whereas quercitol was only found in oak-aged wines. <i>chiro</i>-Inositol was not detected in some commercial wines, indicating that the amount of this cyclitol could change with grape variety. The concentration of quercitol increased with aging time and depended on the age and characteristics of the barrels, but not on the grape variety used. For the other cyclitols, aging in oak barrels did not appreciably modify the concentration in each batch. In oak chip-treated wines, quercitol was also present and its concentration was influenced by chip size. Quercitol seems to be a potential new indicator of the contact of wine with oak wood.

Influence of Saccharomyces cerevisiae strains on wine total antioxidant capacity evaluated by photochemiluminescence

A preliminary investigation on 20 Aglianico del Vulture commercial wines from the Basilicata region proved the existence of a significant variability in total antioxidant capacity which can exert a potential impact on wine quality. Nineteen Saccharomyces cerevisiae strains were tested in Aglianico del Vulture on pilot scale fermentation and the experimental wines obtained were evaluated for the antioxidant capacity, ethanol and total polyphenols. At the ninth day of fermentation the experimental wines had an antioxidant capacity, measured by photochemiluminescence, between 2.88 and 6.25 mM of ascorbic acid equivalent, ethanol concentration, measured by GC, between 5.49% and 10.99% and total polyphenols, determined by Folin Ciocalteau reagent, from 1153 to 1867 mg catechins/l. After 12 days the total antioxidant capacity was increased in most wines but decreased in some wines. These results, statistically analysed by principal component analysis, revealed a significant influence of S. cerevisiae strain on total antioxidant capacity and total polyphenols content of wine.

Influence of Vineyard Location and Vine Water Status on Fruit Maturation of Nonirrigated Cv. Agiorgitiko (Vitis viniferaL.). Effects on Wine Phenolic and Aroma Components

The influence of site on grape and wine composition was investigated for Vitis vinifera L. cv. Agiorgitiko in the Nemea appellation area in southern Greece. Three nonirrigated plots were studied during the 1997 and 1998 vintages, which were typically very hot and without summer rainfall. Vines were subjected to different water regimens as a result of the variation of soil water-holding capacity and evaporative demand. Vine water status was determined by means of predawn leaf water potential. Differences in vine water status between sites were highly correlated with the earliness of shoot growth cessation and veraison. Grape composition was monitored during fruit ripening. Water deficit accelerated sugar accumulation and malic acid breakdown in the juice. Early water deficit during the growth period was demonstrated to have beneficial effects on the concentration of anthocyanins and total phenolics in berry skins. A similar pattern was observed for the phenolic content of wines elaborated after vinification of grapes harvested on each plot, in both seasons. Limited water availability seemed to increase glycoconjugates of the main aromatic components of grapes as a quantitative increase in levels of bound volatile compounds of the experimental wines was observed under water deficit in both years. Wines produced from grapes of stressed vineyards were also preferred in tasting trials.

Winemaking Ability of Wild Yeast Strains and Comparative Volatile Profiles of Wines Fermented at 12.DEG. or 20.DEG.C.

Several wild yeast strains isolated from spontaneous must fermentation were tested for use in winemaking. The ability of Saccharomyces cerevisiae GR7 and GR3 to produce a regular fermentation process, complete fermentation, and produce ethanol and low volatile acidity at both 12°C and 20°C indicate that both strains are promising as starter cultures in winemaking. The effect of wild yeast strains on the relative composition of several volatile compounds in wines fermented at 12°C or 20°C was also studied. Pinot Grigio must fermentation was carried out using selected yeast strains. In addition, Debina and Roditis wines were made by spontaneous must fermentation. Experimental wines were analyzed for volatile compounds using solid phase microextraction and GC-MS analysis. In all wines fermented at 12°C, most acetate esters, ethyl esters, higher alcohols and fatty acids were lower than in those fermented at 20°C.

Prediction of perceived astringency induced by phenolic compounds II: Criteria for panel selection and preliminary application on wine samples

In the following work, subject saliva characteristics affecting panel astringency evaluation in phenolic mixtures were studied. Sixty subjects were selected on the basis of their salivary flow, haze developing capacity and protein concentration. Subjects rated the perceived astringency of tannic acid (TA), commercial procyanidin (PA) and grape seed extract (GSE) solutions with concentration values ranging from 0.42 to 1.4 g/L. Astringency intensity perception proved to be inversely related to saliva flow rate and haze developing capacity. No significant correlations were found between saliva protein concentration and intensity of astringency perception. A panel selected on the basis of subject similarity for flow rate and haze developing capacity rated the astringency intensity of set sample training solutions of TA, PA and GSE with concentrations ranging from 0.39 to 4.48 g/L. The reactivity of the same astringent solutions with mucin was measured in an in vitro assay and expressed in terms of Nephelometric Turbidity Units (NTU). Three predictive models described by a linear regression of astringency intensity vs. NTU were found. The possibility of a practical application of the proposed assay for optimization of wine production was evaluated on 18 experimental wines. A linear correlation was found between the intensity astringency ratings of wine samples and the in vitro assay response.

The Impact of Information on Wine Auction Prices: Results of an Experiment

This paper reports the results of an experimental wine auction. Participants of the experiment were randomly assigned to three rooms. In each room four wines had to be evaluated, but the level of information to which participants had access differed across rooms. After the evaluations, the wines were sold sequentially, by four separate Vickrey auctions with secret reservation prices. We fi nd that certain socio-economic characteristics such as gender, income and consumption habits, have a signifi cant impact on the willingness to pay for wine, while others such as age and nationality, do not. We also fi nd that once individuals have read the label characteristics and extracts from wine guides, the taste of the wines does not have an additional impact on willingness to pay. Conversely, if individuals who have only tasted the wines blindly are informed about the wine characteristics and opinions from experts, their willingness to pay increases substantially.

English

Wines contain a large array of phenolic compounds, belonging to non-flavonoids, flavonoids and phenolic-protein-polysaccharide complexes. Phenolics in wine are responsible for wine color, astringency, and bitterness. This study evaluates phenolic composition of commercial and experimental wines derived from bunch (Vitis vinifera) and muscadine (Vitis rotundifolia) grapes to determine compositional differences in phenolics. HPLC analysis of wines showed that majority of phenolic compounds eluted during the first 30 min. Of the red wines tested, Château Cabrieres Chateauneuf de Pape (Rhone) showed the simplest phenolics profile while Cabernet Sauvignon (Vitis vinifera-California) showed the most complex profile. The phenolics composition of red and white wines varied greatly. Some white wines from bunch grape were devoid of any phenolics. Among muscadine white wines, some contained large number of phenolic compounds while the others showed smaller number of phenolic compounds. These data suggested that both the red and white wines contained a complex mixture of phenolic compounds whose content and composition varied by brand suggesting that the wine processing technique greatly influences phenolics composition of wines than color of the wine. Muscadine red wines were quite distinct than that of the bunch grapes, indicating that grape chemistry has a greater influence on wine phenolic composition.

Trans-Resveratrol, quercetin, (+)-catechin, and (-)-epicatechin content in south Italian monovarietal wines: relationship with maceration time and marc pressing during winemaking.

The concentrations of trans-resveratrol, (+)-catechin, (-)-epicatechin, and quercetin were evaluated by means of high-performance liquid chromatography-diode array detection in red wines obtained from Aglianico, Piedirosso, and Nerello Mascalese grapes. The trans-resveratrol and epicatechin concentrations did not differ significantly between experimental wines. The concentration of quercetin in Nerello Mascalese wines was more than twice that observed in Aglianico and Piedirosso wines. Nerello Mascalese wines also significantly differed from other wines in the (+)-catechin content, which was significantly higher than those found in the other two wines. During maceration, the maximum extraction of trans-resveratrol was reached after 12 days for Aglianico and Piedirosso, after which a decline was observed. On the contrary, in the case of Nerello Mascalese, the concentration of trans-resveratrol increased steadily throughout the whole maceration process. After 2 days of maceration, the maximum concentration of quercetin was observed in Aglianico must, whereas the maximum quercetin extraction was reached after 12 days for Piedirosso and 17 days for Nerello Mascalese. The maximum levels of (+)-catechin and (-)-epicatechin were generally observed after 12 days of maceration for all wines, although a decline of (-)-epicatechin occurred after maximum extraction in Aglianico and Piedirosso wines. Following marc pressing, a significant increase in the concentration of trans-resveratrol for Aglianico, (+)-catechin and (-)-epicatechin for Piedirosso, and (-)-epicatechin for Nerello Mascalese was observed.

Ochratoxin A occurrence in experimental wines in relationship with different pesticide treatments on grapes

A reversed-phase HPLC method was utilized for Ocrhratoxin A (OTA) determination in 23 white and red wine samples produced in the year 2000. All were come from some vineyards, treated with different pesticides, located in three Italian regions. Analytical methods included commercial immunoaffinity columns and a HPLC system equipped with a RF detector. The sensitivity of the analytical method was 0.01 ng ml −1. Values of OTA found in wine samples show that OTA is more frequently detected in red than in white wines. In fact, all red wine samples were contaminated. The OTA levels reported in this work are comparable with those reported for mycotoxin in red wine. Moreover, the different contents of Ochratoxin A in the wines can be considered an efficiency index of pesticides used.