Cabernet Franc Wines Research Articles

Volatile aroma compound-based decoding and prediction of sweet berry aromas in dry red wine

To explore the volatile markers of typical sweet berry flavors in dry red wine, Marselan, Cabernet Sauvignon, Merlot, and Cabernet Franc wines were pretreated using solid-phase microextraction (SPME) and liquid-liquid extraction-solvent-assisted flavor evaporation (LLE-SAFE), and key odorants were analyzed using sensomics approach. Results indicated that Marselan wines exhibited intense sweet berry aromas compared to other varieties wines. Omission tests on one- and four-year-aged wines identified β-damascenone, isoamyl acetate, 2,3-butanediol, phenylethanol as sweet aroma markers, while geranyl acetone, ethyl isobutyrate, ethyl 2-methylbutyrate as berry aroma markers, which were verified by partial least squares regression. Meanwhile, optimal flavor intensity prediction models between sweet/berry aroma and volatile markers natural logarithms concentration were created with all wines. Moreover, consistent with aroma intensity, most berry markers content increased during aging while sweet markers decreased. This study completes the analytical methodology for volatile markers of wine typical aroma and provides theoretical support for wine flavor prediction.

Hybrid variety Dionis (Cabernet Franc E11 × Panonia) vs. Cabernet Franc wines: Comparative study of chemical profile, in vitro biological activity, sensory quality and potential health risk

In the 20th century, resistant grape varieties did not succeed due to the lack of wine quality analyses prior to introduction to the market. Thus, newly created resistant varieties should be tested for wine quality characteristics. This study evaluates new, resistant interspecies variety Dionis and parental Cabernet Franc wines (vintages 2017−2021): chemical characteristics (oenological parameters; polyphenolic profile by HPLC analysis), in vitro biological activity (biochemical and cell-based assays related to enzyme inhibitory, antioxidant and anti-inflammatory activity), safety aspects (ochratoxin A (OTA) occurrence), and sensory profile. According to oenological parameters, Dionis wine is very similar to Cabernet Franc wine. The most abundant phenolic acid in all samples was gallic acid (14.77−99.08 mg/L), catechin (8.12–41.09 mg/L) was the dominant flavonoid, and malvidin-3-O-glucoside (1.5–120.8 mg/L) the leading anthocyanin. Some differences in polyphenolic profile arose due to variety; annual environmental factors probably do not have great impact. All samples expressed considerable in vitro biological activity, reasonably correlated with content of some polyphenolics, such as anthocyanins. OTA was not detected in any sample. In general, sensory properties of Dionis and Cabernet Franc were similar, while, dependent on vintage, Dionis showed a more variable sensory profile.

Classification of Cabernet Franc Wines from Different Geographical Indications of Mendoza, Argentina, by Descriptive Sensory Analysis and Phenolic Profiles

Classification of Cabernet Franc Wines from Different Geographical Indications of Mendoza, Argentina, by Descriptive Sensory Analysis and Phenolic Profiles

Analysis of Volatile Aroma Compounds and Sensory Characteristics Contributing to Regional Style of Red Wines from Hexi Corridor Based on Sixteen Grape Varieties/Clones

Hexi Corridor is an excellent region for high-quality wines in China, but the characteristic and style of red wine from this region is unclear. To elucidate the regional style of red wines from Hexi Corridor, the aroma properties of red wines made from 16 different varieties/clones of grapes were comprehensively analyzed using HS-SPME-GC-MS, sensory evaluation, odor activity value method, and partial least squares regression analyses. We identified 52 aroma compounds and found that floral and black berry provided a good reference for shaping red wine style and selecting related varieties in Hexi Corridor region. Ethyl caproate, (Z)-3-hexen-1-ol, ethyl 9-decenoate, and hexyl alcohol, which were the characteristic aroma substances of Hexi Corridor red wines, had positive effects on the floral aroma of Merlot, Cabernet Sauvignon, Pinot Noir, and Malbec wines. Hexyl alcohol and (Z)-3-hexen-1-ol also contributed to the black berry and spice aromas, while isobutyl acetate opposed the expression of these aromas of Malbec and Cabernet Franc wines. These results showed that the sensory characteristics of floral and black berry are of vital significance in shaping the red wine style of Hexi Corridor, among which ethyl caproate, (Z)-3-hexen-1-ol, ethyl 9-decenoate, and hexyl alcohol are important contributors.

Influence of in‐amphorae vinification on the molecular profile of Sangiovese and Cabernet Franc

AbstractIn the last decade, some wine producers have re‐evaluated the role of micro‐oxygenation guaranteed by the porosity of the earthenware in the fermentation and refinement phases and, thus, the potential and limitations of this technique on the flavour and aromatic profile of wine need further investigations. The wine volatile profile was analysed by headspace solid phase microextraction coupled with gas chromatography—mass spectrometry, and the volatile compound percentages in Sangiovese and Cabernet Franc vinified in Stainless Steel Containers and in amphorae over time were compared. Results showed that the in‐amphorae vinification enhances the aromatic components of the Cabernet Franc wine, while there is no substantial difference for Sangiovese wine. A metabolomic approach was also attempted for the first time, and the NMR analysis highlighted a difference between the spectra of the samples vinified in‐amphorae with respect to those vinified in steel suggesting a potential new approach to obtain a significant traceability.

Modification of Sensory Expression of 3-Isobutyl-2-methoxypyrazine in Wines through Blending Technique.

Sensory interactions exist between 3-alkyl-2-methoxypyrazines and various volatiles in wines. In this study, the binary blending of Cabernet Franc wines containing high levels of MPs and three monovarietal red wines with two proportions was conducted after fermentation. Volatiles were detected by gas chromatography-mass spectrometry (GC-MS), and wines were evaluated by quantitative descriptive analysis at three-month intervals during six-month bottle aging. Results showed blending wines exhibited lower intensity of ‘green pepper’, especially CFC samples blended by Cabernet Sauvignon wines with an even higher concentration of 3-isobutyl-2-methoxypyrazine (IBMP). Based on Pearson correlation analysis, acetates could promote the expression of ‘tropical fruity’ and suppress ‘green pepper’ caused by IBMP. Positive correlation was observed among ‘green pepper’, ‘herbaceous’, and ‘berry’. The concentration balance between IBMP and other volatiles associated with ‘green pepper’ and fruity notes was further investigated through sensory experiments in aroma reconstitution. Higher pleasant fruity perception was obtained with the concentration proportion of 1-hexanol (1000 μg/L), isoamyl acetate (550 μg/L), ethyl hexanoate (400 μg/L), and ethyl octanoate (900 μg/L) as in CFC samples. Blending wines with proper concentration of those volatiles would be efficient to weaken ‘green pepper’ and highlight fruity notes, which provided scientific theory on sensory modification of IBMP through blending technique.

Chloroanisoles occurrence in wine from grapes subjected to electrolyzed water treatments in the vineyard

Recently the use of electrolyzed water (EW) attracted much attention as a high-performance, new technology for its potential use in the food industry. The aim of this work was to investigate the impact of grape EW treatments, applied at different time intervals prior to harvest, on the indigenous yeast populations of grape surface (Chenin blanc and Cabernet franc) and the occurrence of 2,4,6-trichloroanisole (TCA) in Cabernet franc wine. In addition, the evolution of inoculated and spontaneous fermentations on treated and non-treated grapes was also considered. The yeast population present on grape berries surface was influenced in a grape variety and EW treatment time-dependent way, since only Chenin blanc grapes treated with EW 7 days prior to harvest had significantly lower yeast population levels, compared to the respective control. Concerning the yeast diversity in the grape samples, a dominance of Aureobasidium pullulans was observed in treated grapes, independently of the grape variety. At the end of alcoholic fermentation, 2,4,6-trichloroanisole was detected in wine when the EW solution was applied at one or two weeks before harvest time. After wine storage, 2,4,6-trichloroanisole and chlorophenols contents generally exhibited a loss relative to initial values. The results showed that EW treatments tended to slightly increase the TCA concentration in final wine and did not affect the fermentation performances and chromatic properties of resulting wine. On the other hand, absorption or desorption phenomena by wine lees could be involved in the change of 2,4,6-trichloroanisole concentration in wine during storage time.

Comparison of sensory evaluation techniques for Hungarian wines

AbstractThe aim of this study was to compare different Hungarian Kadarka, Kékfrankos, and Cabernet franc wines produced and aged by the same methods and to compare two types of sensory analysis methods as well: the 100‐point OIV system and quantitative descriptive analysis (QDA). Both tests were conducted by 12 assessors of the University of Pécs, Institute for Regional Development, Faculty of Horticulture and Oenology. This study provides conclusions about the use of sensory analysis methods, highlighting the advantages and disadvantages of QDA and the OIV system. Principal component analysis, analysis of variance (ANOVA), multiple factor analysis, and partial least squares dicriminant analysis were used for the evaluation of the data. Our results showed that the sensory panel was able to discriminate the samples by both sensory methods; however, the information provided by them was significantly different. ANOVA clearly showed that the two methods have different sensitivity when comparing wines (commercial and produced wine samples) and QDA proved to be the more sensitive, as well as more detailed, method. Partial least squares discriminant analysis augmented the findings in the classification part of the different type of wine samples. In general, OIV is able to show the general quality of the wines, while QDA coupled with proper chemometric methods is able to describe why the given samples received good or bad OIV scores.

Raleio de cachos próximo ao ‘véraison’ nas variedades ‘Montepulciano’ e ‘Cabernet Franc’ em região de elevada altitude do sul do Brasil

The objective of this study was to evaluate the effects of pre- and post-veraison cluster thinning on the physicochemical characteristics of Montepulciano and Cabernet Franc grape varieties grown in regions 900 m above sea level (ASL) in Santa Catarina, southern region of Brazil. The experiment was conducted in two commercial vineyards, Montepulciano vineyard located at 28o12'58''S, 50o06'45''W, 1,185 m ASL during the 2007, 2008 and 2009 vintages; and Cabernet Franc vineyard located at 28°15'20S, 49°56'60W, 1,284 m ASL, during the 2010 and 2011 vintages. Treatments consisted on cluster thinning at three distinct moments for both varieties: during veraison, about 15 days pre-veraison and 15 days post-veraison. For Montepulciano, when cluster thinning is performed post-veraison, there is a reduction in cluster mass and a slight reduction on the acidity of grapes. For Cabernet Franc, when cluster thinning is performed during veraison, there is an increase in total soluble solids of grapes. In general, cluster thinning is recommended two weeks pre- or post-veraison for Montepulciano and Cabernet Franc wine grapes produced in southern Brazilian highlands.

Impacts of natural yield variances on wine composition and sensory attributes ofVitis viniferacultivars Riesling and Cabernet Franc

Impacts of naturally-varying yields on composition and sensory attributes of Ontario Riesling and Cabernet Franc wines were investigated. The sites investigated represented five Vintners Quality Alliance sub-appellations. A grid pattern of sentinel vines was established in each vineyard for data collection. Yields were divided into categories [low, medium, or high (LY, MY, HY)] at harvest (2010, 2011) and replicate wines were made from each. Wines were subjected to sensory sorting tasks to confirm differences between yield categories and sites, and were thereafter subjected to descriptive analysis. All HY vines had higher clusters/vine, berry weights, and Ravaz indices. The HY Cabernet Franc wines had lower colour, anthocyanins, and phenols. Sensory sorting revealed differences amongst wines and descriptive analysis demonstrated several aroma/flavour attributes between yield categories. The HY Riesling wines had less fruit and honey and higher mineral and floral attributes, whereas HY Cabernet Franc wines displayed higher bell pepper, vegetal, and herbaceous characteristics and less fruit attributes. Riesling wines from Lincoln Lakeshore North and Niagara Lakeshore sub-appellations had higher mineral or vegetal attributes, Four Mile Creek had more apple/pear, and St. Davids Bench, Beamsville Bench, and Lincoln Lakeshore South displayed higher fruit and citrus. Escarpment Bench and Four Mile Creek Cabernet Franc 2010 wines had the highest bell pepper aroma, Lincoln Lakeshore North displayed the most earthiness, and Lincoln Lakeshore South had the most cooked fruit. In 2011, cooler sites adjacent to Lake Ontario displayed higher vegetal attributes. Zones of differing yields, dependent upon magnitudes of yield differences, can result in substantially different wine sensory properties.

Anthocyanins and polyphenols in Cabernet Franc wines produced with Saccharomyces cerevisiae and Torulaspora delbrueckii yeast strains: Spectrophotometric analysis and effect on selected sensory attributes

Grapes and wine contain phenolics divided into non-flavonoid and flavonoid classes. Yeast modulates the phenolics of wine by adsorption onto yeast cell walls. This may be advantageous for colour and quality. The effect of Torulaspora delbrueckii (654&M2/1) and Saccharomyces cerevisiae (VIN13) on phenolics and sensory attributes of Cabernet Franc wines (2012/2013) were evaluated. Spectrophotometric analysis was used to determine the phenolic content. Sensory analysis was conducted by expert tasters to evaluate the wines. ANOVA showed that polyphenols and anthocyanins were higher in M2/1 + VIN13 wines (2012/2013) than 654 + VIN13 wines. Colour, fruitiness, mouthfeel, sweetness, astringency and quality were different between treatments. 654 + VIN13 wines (2012) were higher in polyphenols, acidity, astringency and mouthfeel than M2/1 + VIN13 wines. M2/1 + VIN13 (2012/2013) had increased colour and quality than 654 + VIN13 wines. Two treatments were identified for Cabernet Franc wines; M2/1 + VIN13 and 654 + VIN13, which resulted in wines with increased colour and wines with increased mouthfeel and astringency, respectively.

A Preliminary Study of Aroma Composition and Impact Odorants of Cabernet Franc Wines under Different Terrain Conditions of the Loess Plateau Region (China).

Due to its appropriate climate characteristics, the Loess Plateau region is considered to be one of the biggest optimal regions for producing high-quality mountain wine in China. However, the complex landform conditions of vineyards are conducive to the formation of mountainous microclimates, which ultimately influence the wine quality. This study aimed to elucidate the influences of three terrain conditions of the Loess Plateau region on the aroma compounds of Cabernet Franc wines by using solid phase microextraction (SPME) with gas chromatography-mass spectrometry (GC-MS). A total of 40, 36 and 35 volatiles were identified and quantified from the flat, lower slope and higher slope vineyards, respectively. Esters were the largest group of volatiles, accounting for 54.6–56.6% of total volatiles, followed by alcohols. Wines from the slope lands had the higher levels of aroma compounds than that from flat land. According to their aroma-active values (OAVs), ethyl hexanoate, ethyl octanoate and isoamyl acetate were the most powerful compounds among the eight impact odorants, showing only quantitative but not qualitative differences between the three terrain wines. The shapes of the OAVs for three terrain wines were very similar.

Wine Chemical Composition and Radical Scavenging Activity of Some Cabernet Franc Clones.

Three clones of Cabernet Franc (Nos. 02, 010 and 012) were selected in the last phase of clonal selection in Serbia. Wines made from each clone were assessed for quality parameters and taste during five consecutive vintages (2008-2012) and compared to the standard. The wine quality was determined based on the following parameters: alcohol, total extract, anthocyanins, tannins, pH, titratable acidity, volatile acidity, aldehydes, esters and reducing sugars, relative density, ash, colour, tonality, and tasting score. In the last year of the study, grapes and wines of Cabernet Franc clones and a standard were subjected to a chemical analysis of their phenolic composition, resveratrol and radical scavenging activity. In the last year of the study, grapes and wines of Cabernet Franc clones and a standard were subjected to a chemical analysis of their phenolic composition, resveratrol and radical scavenging activity. Chemical analyses of grapes and wines along with sensory and radical scavenging activity evaluations were done according to the standard procedures. The wines of the clone No. 010 showed some superior properties compared to the other two clones and the standard; in five-year period the average concentration of anthocyanins (179±3.8 mg/L) and polyphenolics (1.85±0.02 g/L) was significantly higher than in wines of clones and the standard, (168-173 mg/L and 1.63-1.74 g/L for anthocyanins and phenolics, respectively). Furthermore, the same clone had a higher alcohol content (13.97±0.03%) in each year of the study, which indicated that it ripened faster than other clones (13.06-13.08 %) and compared to the standard (13.04±0.07%). This finding suggested that the clone No. 010 could possibly have a significant economic impact and further increase popularity of Cabernet Franc in a cooler climate viticultural region. It was also found to have the highest contents of aldehydes (488±1.54 mg/L) and esters (322±0.71 mg/L) compared to aldehydes (452-467 mg/L) and esters (290-310 mg/L) measured in other wines. Finally, the highest amount of phenolic compounds (1220±40 mg/kg) and resveratrol (70±3.3 mg/kg) were found in the grapes of the clone No. 010. The present study revealed a strong correlation of total phenolic contents and anthocyanins with radical scavenging activities (0.936 and 0.929, P<0.001, respectively) indicating that this activity of wines was derived mainly from their phenolic compounds. The wine of the clone No. 010 contained the highest concentration of aldehydes, esters, anthocyanins, polyphenolics and resveratrol and consequently achieved the best tasting score. This clone may offer a new Cabernet Franc wine with geographical indication.

Effect of Torulaspora delbrueckii Yeast on the Anthocyanin and Flavanol Concentrations of Cabernet franc and Pinotage Wines

Pinotage and Cabernet franc grape must were inoculated with Saccharomyces cerevisiae and Torulaspora delbrueckii yeasts. Differences in colour were observed between Pinotage (S. cerevisiae) and Pinotage (T. delbrueckii) wines, whereas differences in berry and herbaceous character were observed between Cabernet franc (S. cerevisiae) and Cabernet franc (T. delbrueckii) wines. Mouthfeel properties between treatments for both wines were not significantly different. Overall quality was slightly higher in wines inoculated with T. delbrueckii compared to wines inoculated with S. cerevisiae. Anthocyanins and flavanols measured in Pinotage wines made with T. delbrueckii were higher compared to Pinotage must inoculated with S. cerevisiae. Cabernet franc wines made with S. cerevisiae were higher in anthocyanin glycoside and flavanol concentrations compared to Cabernet franc wines made with T. delbrueckii. Insignificant differences in acetylated and coumarylated anthocyanins were evident between Cabernet franc (S. cerevisiae) and Cabernet franc (T. delbrueckii) wines. Principal component analysis showed that epigallocatechin gallate, epicatechin gallate, procyanidin B2, peonidin 3-O-glucoside, delphinidin 3-(6-acetyl) glucoside, petunidin 3-(6-acetyl) glucoside, malvidin 3-(6-acetyl) glucoside and malvidin 3-O-glucoside concentrations were highest in Pinotage wines inoculated with T. delbrueckii. Cabernet franc wines inoculated with S. cerevisiae yeasts were highest in malvidin 3-(6-p-coumaroyl) glucoside, petunidin 3-(6-p-coumaroyl) glucoside, petunidin 3-O-glucoside, epicatechin gallate and epigallocatechin gallate concentrations. Total anthocyanins were highest in Pinotage (S. cerevisiae) wines and Cabernet franc (T. delbrueckii) wines. Flavanols were highest in Pinotage (T. delbrueckii) and Cabernet franc (S. cerevisiae) wines. It is evident from the results that yeast species has an impact on the flavonoid concentrations within a grape variety.

The natural product content of the selected Cabernet Franc wine samples originating from Serbia: a case study of phenolics

This work aimed to evaluate the content of selected phenolic natural products in the wine samples made of three new Serbian Cabernet Franc clones (Nos. 02, 010 and 012, respectively) and mother vine (used as the relevant standard) during the period 2008–2012. Compared with all other wine samples, the Cabernet Franc wine of the clone No. 010 was found to have the highest total content of polyphenolics (1.85 ± 0.02 g/L) and anthocyanins (178.55 ± 3.75 mg/L). In addition, its Folin–Ciocalteu index (36.86 ± 0.12) stood out among the examined samples. Finally, the same wine was enriched with ellagic and gallic acids (3.44 ± 0.29 and 27.46 ± 0.21 mg/L, respectively), catechin (135.16 ± 6.47 mg/L) and epicatechin (51.33 ± 2.33 mg/L), the natural products known to exert significant lipid-lowering effects. Taken all together, the clone No. 010 developed in Serbia may offer new Cabernet Franc wine with geographical indication.

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

Evaluating the correlation between chemical and sensory compounds in Blaufränkisch and Cabernet Franc wines

The positive physiological effects of the bioactive compounds of red wines have been known for a long time. Besides that, the polyphenolic compounds of red wines represent one of the most important factors for oenology. With a special chemical analysis, we discover the relationship between chemical and sensory compounds. In this way, we explore which compounds influence sensory properties. The phenolic compounds are the quality attributes of the wine. The analysis of phenolic compounds was carried out in two red wines: Cabernet Franc and Blaufränkisch. The aim of this study was to analyse the chemical and organoleptic characteristics of these two wines and evaluate the connection between the two parameters. In addition, we also examined the influence of the polyphenolic content on sensory perception. The experiment was carried out in a cool climate wine region in Eger, Hungary, in vintage of 2008. We investigated the profile of phenolic contents in new and aged wines. Total polyphenolic content, anthocyanin, leucoanthocyanin and catechin were evaluated by spectrophotometer. Stilbenes were identified and quantified by high-performance liquid chromatography.

Evaluating the correlation between chemical and sensory compounds in Blaufränkisch and Cabernet Franc wines

The positive physiological effects of the bioactive compounds of red wines have been known for a long time. Besides that, the polyphenolic compounds of red wines represent one of the most important factors for oenology. With a special chemical analysis, we discover the relationship between chemical and sensory compounds. In this way, we explore which compounds influence sensory properties. The phenolic compounds are the quality attributes of the wine. The analysis of phenolic compounds was carried out in two red wines: Cabernet Franc and Blaufränkisch. The aim of this study was to analyse the chemical and organoleptic characteristics of these two wines and evaluate the connection between the two parameters. In addition, we also examined the influence of the polyphenolic content on sensory perception. The experiment was carried out in a cool climate wine region in Eger, Hungary, in vintage of 2008. We investigated the profile of phenolic contents in new and aged wines. Total polyphenolic content, anthocyanin, leucoanthocyanin and catechin were evaluated by spectrophotometer. Stilbenes were identified and quantified by high-performance liquid chromatography.

Exemplarity measurement and estimation of the level of interjudge agreement for two categories of French red wines

Exemplarity measurements of wines by at least 20 judges are used to estimate the degree of interjudge (dis)agreement and to tell wines apart into two contrasting extremes. Two sets of French red wines – Pinot noir from Burgundy and Cabernet franc from the Loire Valley – are studied separately but by the same approach. Short-listing criteria are used to collate 40 starting-price and middle-range wines for each set differing a priori in olfactory terms. Wine professionals assess their local wines first orthonasally and then, independently, by global evaluation. A pool of descriptive and inferential statistics indicates there is generally neither complete divergence nor real agreement among judges. For Burgundy Pinot noir, the weak agreement observed and measured for orthonasal evaluation strengthens slightly for global evaluation. Contrariwise, for Loire Valley Cabernet franc wines, agreement is poorer for global evaluation than for olfactory evaluation. With orthonasal evaluation, responses are more consistent for Cabernet franc than for Pinot noir, whereas for global evaluation, the levels of interjudge agreement are of the same order for both sets of wines. The subjectivity of sensory responses is interpreted for each situation. The personal judgment of exemplarity (or typicality) may therefore be defined as a demanding cognitive decision varying with the circumstances of the experiment and responding to a process of perceptual categorization based on previous knowledge and on an intuitive comparison between a sample and an abstract but conscious image of the category. Agreement among judges is sufficient to bipolarize the wines. As the power to discriminate among the wines is related to the level of interjudge agreement, bipolarization is most marked for the Cabernet franc wines evaluated by olfactory evaluation.

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.