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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.

Electrolyzed water (EW) has attracted much recent attention as a high-performance, new technology for its potential use in the food industry. However, the risk of postharvest EW treatments of winegrapes destined for winemaking is the chloroanisoles formation in the final product. In the present study, we investigated the impact of postharvest grape EW and storage treatments on the occurrence of these compounds in wine, 2,4,6-trichloroanisole (TCA) being the main compound responsible for the cork taint off-flavor due to its extremely low perception threshold. The results revealed that the presence of TCA in the wines depended on the concentration of residual free chlorine in the must from the EW treatment. Particularly, TCA was not detected in wine when active chlorine concentrations higher than 0.005 mg/L were present in the must. Chloroanisole and chlorophenol levels in wine were strongly affected not only by EW but also by grape storage conditions (temperature, time, sunlight exposition). The results showed that the 24-hours grape storage at a controlled temperature of 20 °C in the dark, after EW treatment, resulted in the highest TCA concentrations in wines (7.3 ± 2.7 ng/L), while storage and withering in sunlight seemed to mitigate its presence in wine. This could suggest that microbiological formation of chloroanisoles may have been influenced by the storage temperature and germicidal effect of UV light. Biochemical mechanism of chloroanisoles production in grapes and wine is unknown, but the combination of residual free chlorine on the grape surface and the controlled storage conditions in the dark may have positively influenced the bio-formation of chloroanisoles and therefore their presence in wine.

Moscato nero d'Acqui is an Italian aromatic black winegrape variety characterized by a low content of anthocyanins (mostly tri-substituted), a satisfactory content of high molecular mass tannins, and a fair amount of terpenes. The grapes were subjected to a postharvest dehydration process under controlled thermohygrometric conditions (16-18. C, 55-70 RH%, 0.6. m/s air speed) with the aim to produce three different special wine types (fortified, . sfursat, and . passito) from fresh, partially dehydrated (27Brix), and withered (36Brix) grapes, respectively. Chemical traits of produced grapes and wines were then evaluated through spectrophotometric, HPLC, and GC-MS methods. Increased contents of skin phenolic compounds and reduced extractable contents of seed phenolic compounds were observed as dehydration progressed. Few significant differences were found in the anthocyanin profile of grapes, although the relative abundance of coumaroylated anthocyanins was higher in dehydrated grapes. The predominant free volatile compound found in grapes was geraniol, which decreased with increasing water loss, whereas the contents of major glycosylated volatile compounds increased even above the concentration effect. The changes in the phenolic composition among wines agreed with those among grape skins. . Fortified wines were chromatically unsatisfactory probably due to the low content of total anthocyanins, whereas . sfursat and . passito wines meet good chromatic characteristics as a result of the concentration effect during grape dehydration. . Fortified and . sfursat wines had free aroma profiles richer in 2-phenylethanol and citronellol, whereas . passito wines were mainly composed of 2-phenylethanol and 2-phenylethyl acetate, citronellol being the predominant terpenol in all the wine types studied. © 2016 Elsevier Ltd.

In this work, the chemical compositions and texture characteristics of three native Romanian wine grape varieties (Feteascə regalə, Feteascə alba, and Feteascə neagrə) were studied. We assessed the distinct characteristics directly linked to their phenolic compositions, volatile profiles, and mechanical properties and compared these characteristics with those of Pinot noir grapes. The effect of the growing zone was also evaluated. Various spectrophotometric indices directly related to the phenolic compositions of berry skins and seeds were determined. The detailed phenolic compositions (anthocyanins, hydroxycinnamoyl tartaric acids, and stilbenes) of the skins were determined using high-performance liquid chromatography methods. Free and bound volatile compounds in the berries were quantified by gas chromatography/mass spectrometry. The textural properties of the skins and seeds were measured by instrumental texture analysis. The results showed high diversity among the varieties and zones that affected the enological potential. Among the white varieties, Feteascə albə grapes could be less susceptible to browning as a consequence of their lower trans-caffeoyltartaric acid concentration, whereas Feteascə regalə grapes from Cluj had the highest concentrations of total free and bound volatile compounds, particularly terpenes and norisoprenoids. Among the red varieties, Feteascə neagrə was identified as a promising variety to be exploited in the future for its particular phenolic characteristics, particularly those grapes grown in Mica. Nevertheless, Feteascə neagrə grapes grown in Cluj had the highest total glycosidically bound terpene concentrations. Finally, differences in the mechanical and/or acoustic properties of the skins and seeds could strongly influence the kinetics and completeness of phenolic compound extractions.

This study represents the first time that the extraction of phenolic compounds from the seeds is assessed from instrumental texture properties for dehydrated grapes. Nebbiolo winegrapes were postharvest dehydrated at 20 °C and 41% relative humidity. During the dehydration process, sampling was performed at 15%, 30%, 45% and 60% weight loss. The extractable fraction and extractability of phenolic compounds from the seeds were determined after simulated maceration. The evolution of mechanical and acoustic attributes of intact seeds was also determined during grape dehydration to evaluate how these changes affected the extraction of phenolic compounds. The extractable content and extractability of monomeric flavanols and proanthocyanidins, as well as the galloylation percentage of flavanols, might be predicted easily and quickly from the mechanical and acoustic properties of intact seeds. This would help in decision-making on the optimal dehydration level of winegrapes and the best management of winemaking of dehydrated grapes.

The dipping of berries in a dilute solution of sodium hydroxide during a short time was evaluated as pretreatment undertaken prior to convective dehydration of wine grapes. The impact of the sodium hydroxide content and dipping time on weight loss (WL) at different dehydration times was thoroughly assessed using central composite design (CCD) and response surface methodology (RSM). Furthermore, the effects of these two variables were also investigated on the skin mechanical properties of dehydrated grapes. The effect of these two pretreatment factors on the dehydration kinetics and skin hardness was satisfactorily fitted to regression models. The berry pretreatment with low sodium hydroxide contents (from 10 to 20 g/L) facilitated the dehydration process during the first 5 days when dipping times longer than 300 s were used. From the seventh day of dehydration, at which time the average WL% was close to 50, the highest values of WL% were obtained using intermediate sodium hydroxide contents and dipping times (around 45 g/L and 185 s, respectively). Because skin hardness affects the dehydration kinetics during postharvest withering, the strongest decrease in skin hardness corresponded to these last berry pretreatment conditions, whereas the greatest increase required the highest sodium hydroxide contents and longest dipping times. The quality of berries dehydrated may be influenced by the pretreatment conditions used, and the present study contributes to increase the knowledge on this effect to a better management of the alkaline pretreatment and dehydration process.

The impact of an enzyme preparation on the extraction of grape skin anthocyanins into a wine-like solution was evaluated during maceration (25. °C, 8. days). The study was performed on Vitis vinifera L. cv. Cabernet Sauvignon and Nebbiolo because of their different anthocyanin profiles, which are mainly composed of tri- and disubstituted forms, respectively. Maceration enzymes enhanced the skin releasing capacity for anthocyanins between 8% and 15% more, depending on the enzyme dose and variety, and shortened the time required to reach the maximum extraction yield by about 40. h, when compared to the control samples. The effect of enzymes on the profile and total content of anthocyanins during maceration was significant only for Cabernet Sauvignon. Therefore, a variety effect was found. In particular, the relative amount of malvidin glucosides increased up to 9% more whereas that of delphinidin, cyanidin and peonidin glucosides decreased up to 5%, 2% and 3% more, respectively, with the addition of the enzyme preparation. The results also showed lower anthocyanin degradation at maceration times longer than 72. h with the use of enzymes. Furthermore, the relationship between this enzyme effect and the instrumental skin hardness was assessed for the first time, as no previous study deals with the variation in the mechanical properties of the berry skin after using maceration enzymes. Significant positive relationships were found between the skin softening and the anthocyanin extraction yield (. R>. 0.69, p<. 0.01), which confirmed that the skin degradation by enzymes facilitates the anthocyanin release.

The aim of this work was to determine the impact of using independently berry density and diameter as sorting methodologies on important physicochemical parameters affecting the grape quality, such as mechanical properties, phenolic composition and aromatic profile. Muscat Hamburg berries were classified according to the density by flotation in different salt solutions and to the diameter. The three most representative density (1081, 1088 and 1094 kg/m3) and diameter (16-17, 18-19 and 20-21 mm) classes were selected. The results showed that there were relationships of both density and diameter with the mechanical properties and chemical composition of the berries. Densimetric sorting is a more promising methodology to separate grape berries with different quality attributes, particularly skin hardness, berry cohesiveness and resilience, total hydroxycinnamic acids, anthocyanins and rose oxide, than diameter sorting. This knowledge can be of great interest for the 'fresh-cut' industry in the production of 'ready-to-eat' fruits salad.

Seed mechanical properties were instrumentally measured by compression testing in thirty white and red wine grape varieties at harvest. The effect of berry heterogeneity in a vineyard on these seed texture parameters was also evaluated to improve the understanding of intra-sample variabifity. Furthermore, the mechanical properties of the seeds were assessed as possible predictors of their phenolic extractabifity. The results show that the texture parameters of the seeds are independent of the location of the berry in the vineyard and the soluble solid content at harvest. Densimetric flotation of the berries permits the reduction of the intra-sample variabifity that could hinder the differentiation and/or classification of wine grape varieties according to seed mechanical attributes. Cluster analysis classified the wine grape varieties studied into three groups according to seed hardness (low: 32.51 to 40.80 N, intermediate: 42.84 to 44.99 N, high: 46.71 to 57.78 N). The relationships between the seed mechanical properties and the extractable content of phenolic compounds, determined by spectrophotometric and chromatographic reference chemical methods, were evaluated by means of correlation analysis. Linear regression calibration models were developed for each cluster. The statistical parameters highlighted that total flavonoids, proanthocyanidins and flavanols reactive to vanillin can be predicted successfully from the seed mechanical properties for the varieties having low and intermediate seed hardness (SEC% ca. 20, RPIQ> 1.6). For varieties with harder seeds, a satisfactory predictive accuracy seems to require the construction of separate calibration models for each cultivar (Nebbiolo, SEC% ca. 20, RPIQ> 2.2).

Flesh firmness is a sensory characteristic proposed by Organisation Internationale de la Vigne et du Vin (OIV) as an ampelographic descriptor for grape varieties and Vitis species (OIV code 235). To accurately define the flesh firmness of table grapes, an instrumental texture parameter that makes it possible to classify the five reference table-grape cultivars according to this descriptor was selected. The mechanical properties of the berry flesh were determined by texture profile analysis and cutting tests. The results showed that the berry hardness and gumminess, normalized by berry diameter, are accurate instrumental indicators of flesh firmness because the variations among the cultivars were evident, independently of berry size and maturity grade. The interquartile ranges of berry hardness normalized by berry diameter for each flesh-firmness group established by OIV (soft, slightly firm, very firm) were 0.074 to 0.117, 0.121 to 0.158, and 0.205 to 0.391 N/mm, respectively. This standardized protocol can be applied to better compare the performance of grape varieties.

The evolution of the content and profile of anthocyanins was studied in the skin and pulp of Gamay winegrapes during twelve days of carbonic maceration. The ripening effect was also investigated using berries belonging to two density classes (A = 1094-1100 kg/m3 and B = 1107-1115 kg/m3). The ripest berries showed a higher extraction yield, even though the differences among density classes tended to decline towards the end of the process, and few significant differences were found in the anthocyanin profile. The maceration time influenced strongly not only the content and extraction yield, but also the qualitative composition of anthocyanins towards the predominance of malvidin derivatives. Finally, the extraction yield of anthocyanins was positively related with the ethanol formed and the skin mechanical properties using linear regression models, which showed that the skin hardness is likely to be an important variable in modelling daily anthocyanin extraction during carbonic maceration, particularly from the sixth day.

The feasibility of Fourier transform-near-infrared (FT-NIR) spectroscopy for predicting the extractable content of phenolic compounds directly in intact grape seeds was evaluated. NIR calibration models were based on the correlation of spectral data with the phenolic composition determined by reference chemical methods for 40 grape samples. The vintage effect was studied evidencing that the predictive accuracy improved only for spectrophotometric indices when samples of two years were simultaneously considered. The statistical parameters of calibration showed that the models developed are sufficiently robust for quantitative purposes of total flavonoids, proanthocyanidins, low molecular weight flavanols, catechin, epicatechin, procyanidin B1, and galloylation percentage (standard prediction error (SEP%) < 15, predictive index (RPIQ) > 3.0), but could be also useful for screening of absorbance at 280 nm, total polymers, epicatechin gallate, and procyanidin B2 (SEP% < 15, RPIQ = 2.7-2.9). Although a calibration model is required for each geographical origin, the results suggest that FT-NIR spectroscopy is a promising analytical technique in this field.

The impact of different ripening stages on berry texture properties of sorted 'Red Globe' and 'Crimson Seedless' table grapes was evaluated. Density sorting at different harvest dates was utilised to obtain homogeneous samples for each ripening stage. At the same ripening stage, 'Red Globe' berries were more firm, cohesive, springy, chewy and resilient but less hard and gummy than 'Crimson Seedless'. Particularly for cv. Red Globe, the choice of the ripening stage at harvest could be a determinant for the berry quality because riper berries were associated with higher skin thickness values (+25%). The berry hardness and gumminess of 'Crimson Seedless' decreased significantly during ripening (-50%), and these parameters were most influenced by the berry size. Conversely, berry cohesiveness can be used as a ripeness predictor of table grapes because the changes during the ripening process were independent of berry size. The peduncle detachment resistance of the berry in the Crimson Seedless grapes decreased to values lower than 3.4. N, negatively affecting the quality attributes of the berry.

By texture analysis tests, the ability of berries to resist rupture under compression load during intracellular fermentation was studied for twenty-three red wine grape varieties. The softest berries were associated with Ancellotta (1.72 N), Dolcetto (1.79 N), Gamay (2.26 N) and Schiava gentile (2.29 N) cultivars. The hardest berries corresponded to Franconia and Bonarda cultivars (4.02-4.03 N). High resistance to splitting was also detected for Grenache, Raboso, Marzemino, Negramaro, Montepulciano and Croatina cultivars (3.50-3.95 N). The differentiating power of the mechanical variables of the whole berry and skin was assessed by univariate and multivariate analysis. Relationships among the instrumental berry hardness and other physical and mechanical properties were also investigated. The results obtained suggest that the manufacture of carbonic macerated wines should be planned considering the berry hardness, and it represents a new variable that should be considered in selecting the most appropriate wine grape variety to elaborate these wines. © 2012 The Authors. International Journal of Food Science and Technology

Summary: The impact of cluster heterogeneity on mechanical properties, chromatic indices and chemical composition of Italia table grape berries sorted by flotation was evaluated in this study. The density sorting at commercial harvest permitted to get berries of different ripeness and relatively different quality attributes. Individually, some grape chromatic characteristics, physical characteristics (weight of the whole berry and berry skin), content and composition of reducing sugars, organic acids and phenolic compounds (flavanols of low molecular mass in berry skins) permitted to characterise and to differentiate berries belonging to different density classes. However, the tested mechanical properties were not related to the berry density. When the variables that significantly contributed to the berry differentiation were globally assessed, the chemical parameters related to sugars (142.3-164.4 g kg-1), content of skin oligomeric flavanols [46.3-137 mg (+)-catechin kg-1], berry skin weight (379-607 mg), yellow/blue colour component (26.31-29.96) and chroma (26.40-30.06) were the more representative.

'Corvina' winegrapes were postharvest withered under three controlled thermohygrometric conditions. Sampling was done on different days of withering and the mechanical properties, technological ripeness parameters, phenolic composition, and anthocyanin profile were determined. Depending on the condition, skin break force and pedicel detachment force significantly decreased during the dehydration process with a maximum variation of -0.258 and -1.306 N, respectively. Instead, total flavonoids of skin and seeds, and proanthocyanidins and low-weight flavanols of seeds increased, with a maximum variation of +1,483, +733, +1,022, and +469 mg/kg, respectively. The skin hardness was confirmed to be an important parameter for the dehydration kinetics.

The use of instrumental acoustic parameters produced during a compression test as reliable predictors of the extractable phenolic composition in intact winegrape seeds, determined by reference chemical methods, was evaluated by means of the analytical performance of calibration models. These models were developed only for those phenolic compounds most significantly and strongly correlated with the acoustic parameters. The analytical performance of the models was expressed in terms of standard error of cross-validation (SECV) and residual predictive interquartile amplitude (RPIQ), among other statistics. Several acoustic parameters showed satisfactory predictive accuracy for the percentage of galloylation in the terminal units, the content of (-)-epicatechin, and the mean degree of polymerization. Most of the reliable models developed are fairly recommended not for quantitative purposes but for fast screening (SECV% < 19, 1.6 < RPIQ < 2.1).

Aims: Fourier Transform-Near Infrared (FT-NIR) spectrum and instrumental texture parameters were assessed as total phenol content and extractability predictors in intact grape seeds. Methods and results:The study was carried out on Cabernet-Sauvignon seeds from grapes harvested at six different advanced physiological stages throughout ripening and calibrated by flotation to reduce the in-field heterogeneity inside each sample. Among the instrumental mechanical properties tested (i. e., break force, break energy, Young's modulus of elasticity and deformation index), the seed Young's modulus of elasticity showed an increase during the first four weeks of ripening. This parameter also showed significant correlations with phenol content and extractability, although with low R coefficients. These correlations highlighted that the springier seed tissues greatly increase phenol extractability. Nevertheless, the best prediction of seed phenol content, performed directly on intact seeds, was found using FT-NIR spectroscopy in transmittance mode. The standard error of prediction for total phenol content was less than 8 %, while that for phenol extractability was worse. Conclusion: On the basis of these results, the two analytical methods could be applied in oenology for the rapid monitoring of seed phenolic maturity. Significance and impact of the study: The phenolic composition of grapes at the harvest time is a key factor determining their quality, and thus the quality of the finished wine. The chemical methods used for the determination of seed phenol content and extractability are generally slow because they require a preliminary extraction. Therefore, a rapid evaluation of these parameters could be highly interesting for the oenological sector

Instrumental mechanical and acoustic variables were determined for berry seeds of Cabernet Sauvignon grapes harvested at different ripening stages. The main goal of this research was to assess the influence of developmental changes on the texture properties of grape seed to provide useful indicators of maturity. Although most of the instrumental texture properties were characterized by a large intrasample variability, the following indices could be considered indicative of maturity: deformation index, acoustic energy, and average sound pressure. A correlation study between the instrumental mechanical and acoustic variables showed that the Young's modulus of elasticity proved to have the strongest positive correlation with the acoustic variables.

This article presents a detailed study on the influence of winegrape variety, skin hardness of fresh berries, and withering thermo-hygrometric conditions on the dehydration kinetics of the grape. Although some works focused on the changes in the weight loss rate during grape dehydration under different environment conditions for several varieties, the combined effect of the skin mechanical properties and the thermo-hygrometric conditions has not been previously considered. The skin break force was confirmed as the varietal marker. Furthermore, its role in the selection of the withering conditions was assessed. The fresh grape berries were classified into two groups (soft and hard) according to the skin break force, and four off-vine withering conditions were evaluated. The softer skins facilitated the dehydration process increasing the weight loss rate, but the increase was significant only at low temperatures. The increase in temperature and/or decrease in relative humidity was beneficial to the grape dehydration process. A weight loss of about 50% after 12 days of withering was achieved at an air temperature of 28°C and relative humidity of 40%. Under the same dryer environmental conditions, a certain varietal effect on the dehydration kinetics was observed because a faster weight loss occurred for those grapes characterized by lower values of skin break force. These results suggest that the grape dehydration rate, influencing the quality of dessert wines, should be planned considering the skin hardness of fresh berries and the withering conditions. The skin break force represents a new variable that should be considered in modeling the withering process and in selecting, prior to harvest, the most appropriate vineyard for the dessert wines desired.

In vineyards, in-field grape variability attributable to environmental factors can induce differences in the ripening process and, therefore, in the physicochemical characteristics of grape berries. This variability is often higher among different growing locations. Automatic, densimetric berry-sorting machines have recently been developed and proposed for use in wineries to reduce this variability, thereby making grapes uniform in terms of density. Densimetric sorting requires the selection of a density value according to objective quality parameters of the berries. The aim of this work was to determine the relationships among different objective quality parameters of Nebbiolo grapes harvested on the same date, such as mechanical properties, phenolic composition, and extractability indices; to determine the berry density estimated by flotation in different salt solutions of densities ranging from 1069 to 1125 kg m-3; and to investigate the influence of the growing location on these relationships. The results revealed that the most promising physicochemical parameters for determining the appropriate density are the total anthocyanin and flavonoid concentrations in the skins, the total flavonoid and oligomer proanthocyanidin contents in the seeds, and skin hardness and thickness. Nevertheless, density selection must be performed for each individual vineyard or homogeneous group of vineyards belonging to the same production zone because the correlation of berry density with these parameters also depends on the vineyard effect. Densimetric sorting of berries can be used to separate grapes with different quality parameters.

An instrumental texture analysis method has been optimized for the differentiation of grape ripening stages based on the simultaneous determination of mechanical and acoustic parameters of the seeds. Two factorial central composite design was used to optimize the most influencing operative conditions (speed and deformation) on mechanical and acoustic measurements. This experimental design in combination with response surface methodology showed that the most responsive parameters to changes in seeds during ripening were Young's modulus of elasticity, many acoustic parameters measured with instrumental gain set to 0 (acoustic energy, linear distance, and number of peaks) and others measured at 24 dB gain (linear distance, number of peaks, and average pressure level). However, the optimal operative conditions depended on the texture parameter used. A correlation study between texture parameters and phenolic compounds of the seeds revealed that acoustic parameters like the average pressure level could be proposed as phenolic maturity indices.

Changes in the phenolic composition, phenol extractability indices, and mechanical properties occur in grape berries during the ripening process, but the heterogeneity of the grapes harvested at different ripening stages affects the reliability of the results obtained. In this work, these changes were studied in Nebbiolo grapes harvested during five consecutive weeks and then separated according to three density classes. The changes observed in chemical and mechanical parameters through the ripening process are more related to berry density than harvest date. Therefore, the winemaker has to select the flotation density according to the objective quality properties of the wine to be elaborated. On the other hand, the stiffer grapes were associated with a higher accumulation of proanthocyanidins. The harder grapes provided the higher concentration and extractability of flavanols reactive to vanillin, whereas the thicker ones facilitated the extraction of proanthocyanidins.

The Brachetto variety is the most important aromatic red grape used for the production of sweet sparkling wines in Italy. The phenolic composition and chromatic characteristics were studied in base and red sweet sparkling wines made from this variety. The present work represents the first study on sparkling wines manufactured with Brachetto grapes. The amount of pigments extracted in the base wine was low as a consequence of the necessity for short maceration time (48. h) and low alcohol content (< 3.5% v/v). The second fermentation (prise de mousse) caused a pigment content decrease, accompanied by both a color intensity decrease and a tonality increase. In terms of phenolic compounds and chromatic characteristics, lightly sparkling wines (final bottle pressure < 1.7. bar) agreed with fully sparkling wines (final bottle pressure > 3.0. bar) at the end of the second fermentation and, therefore, the chromatic quality was independent on the winemaking methodology used, excepting for lightness and color intensity. Response surface methodology was applied to predict the effect of two independent variables, namely time and temperature of storing, on the phenolic composition and chromatic properties in both lightly and fully sparkling wines. So, it is possible to evaluate the development of two types of sweet sparkling wines during their ageing in bottle and their commercial shelf-life. A central composite design (CCD) and response surface methodology (RSM) were used for this purpose. Quantitative changes were observed in the color parameters. Although the time variable strongly influenced them, the two sparkling wines were stable enough only at low temperatures after 12. months of ageing. During the wine ageing in bottle, an increase in the formation of polymeric red pigments can be suggested taking into account the losses observed in monomeric anthocyanins. The results obtained showed that the color of fully sparkling wines was more stable than that of lightly ones and

The phenolic composition and extractability indices of grape berries play a key role in assessing redwine quality because the relationship between grape phenolic maturity and wine phenolic composition is well known. In this work, grape quality indices were determined in Nebbiolo grapes from two growing areas of Langhe (South Piedmont), at different stages throughout the ripening process in six consecutive years (2004 to 2009), with the aim of evaluating the ripening- and growing area-related changes in the grape indices separately. The effect of vintage was also investigated. Ripeness data were compared with analogous data determined in Nebbiolo grapes grown in the Carema area (North Piedmont). The vintage effect far outweighed any changes in the grape indices introduced by the ripening stage, even those arising from differences in the production area. In the Langhe and Carema zones, the average berry mass, pH, total acidity, total anthocyanins extractable at pH 3.2, total flavonoids and non-anthocyanin flavonoids extractable at pH 1, and the seed maturity index were seasonally dependent. The more ripening-affected parameters were the technological ones. This work highlights the importance of determining the phenol extractability, since it provides relevant information that allows improved management of the maceration stage.