Final Wine Research Articles

Pre-fermentative cold maceration in the presence of non-Saccharomyces strains: effect on fermentation behaviour and volatile composition of a red wine

Background and Aims This study evaluated the impact of pre-fermentative cold maceration (PCM), in the presence of two non-Saccharomyces yeasts, Metschnikowia pulcherrima MP 346 and Metschnikowia fructicola MF 98-3, and of a commercial pectic enzyme, on fermentation kinetics and on the volatile composition of a Sangiovese red wine. Methods and Results Sangiovese grape must was inoculated with MP 346 or MF 98-3 or treated with a pectic enzyme preparation during PCM, at 5°C for 24 or 72 h. A Control wine was produced by a pure culture of Saccharomyces cerevisiae. Both non-Saccharomyces strains affected the initial yeast population dynamics and the persistence of S. cerevisiae at the end of malolactic fermentation. Irrespective of the duration of PCM, the inoculum of Metschnikowia strains did not influence the rate of sugar consumption or the kinetics of malolactic fermentation. The volatile composition of the final wines was evaluated with solid-phase extraction, followed by GC/MS. The concentration of some terpenes and C13-norisoprenoids, nerol, geraniol, 8-hydroxy-linalool (cis) and 3-oxo-α-ionol, and of some esters, isoamyl lactate and ethyl isoamyl succinate, was higher in wines inoculated with Metschnikowia strains than in the Control and wine treated with pectic enzyme. Conclusions Metschnikowia yeast strains MP 346 and MF 98-3 affect wine volatile composition. Significance of the Study This study shows for the first time that an inoculum of Metschnikowia strains MP 346 and MF 98-3 during PCM is effective in modulating the volatile composition of a Sangiovese red wine.

Characterisation of Thiol-releasing and Lower Volatile Acidityforming Intra-genus Hybrid Yeast Strains for Sauvignon blanc Wine

A single Saccharomyces cerevisiae wine yeast strain produces a range of aroma and flavour metabolites (e.g. volatile thiols), as well as unfavourable metabolites (e.g. volatile acidity [VA]) during the alcoholic fermentation of white wine, especially Sauvignon blanc. The former contributes to the organoleptic quality of the final wine. Previous research showed that yeast derived enzymes (proteins) are involved in the release of wine quality enhancing or reducing metabolites during fermentation. Small-scale winemaking trials were initiated to evaluate protein expression and metabolite release of tropical fruit aroma wine producing S. cerevisiae hybrid yeasts. Commercial ‘thiol-releasing’ wine yeasts (TRWY) were included in winemaking trials as references. Improved hybrids were identified which showed enhanced thiol-releasing, specifically 3-mercaptohexanol (3MH), and lower VA formation during the production of Sauvignon blanc wines compared to some commercial TRWY references. It is noteworthy that the hybrid NH 56 produced wines with the second highest 3MH levels after hybrid NH 84, and lowest acetic acid of all strains included in this study. This yeast was also the only strain to have down-regulated proteins linked to amino acid biosynthesis, pentose phosphate pathway, glycolysis and fructose and galactose metabolism during the lag phase. Furthermore, differences in protein expression were reflected in the variation of metabolite release by different strains, thereby confirming that enzymes (proteins) are the final effectors for metabolite release.

Terroir - Myth and/or Reality - Outstanding Marketing Idea? A Review

In former times the term terroir was connatated negatively. “Le goût du terroir” concerned wines, which could not be sold outside a region, because of quality defects. Later, “terroir products” included agricultural goods produced in specific areas. French scientists developed during the last 3 decennials a scientific base for the system “terroir”. All agricultural production systems adhere to a “unité terroir de base (UTB)”. An interaction with viticulture, changes it to a “unité terroir viticole (UTV)”. An UTV together with a farm or an AOC creates an identifiable typicity of wines. Other groups of scientists in esp. in Germany tried to find out the influences of meso- and microclima on quality parameters of grapevines as well as soil, nutrients, water and soil heat budget. Mesoclimatic, geomorphological, and soil parameters can explain approximately 60-70% of the yield formation as well as the sugar accumulation in berries. The unexplained variability adheres to human skills, soil management, harvesting techniques etc.. Following the production chain from bunches to wine increasing interventions occur: juice extraction systems, spontaneous or controlled fermentation with defined yeast strains. Temperature control, filtration systems will exert an influence on the final wine quality. In contrast to the limited intervention during production of grapes, wine making exceed by far the first mentioned and terroir turns to a “quantité negligeable” in the final wine. Nonetheless, on the consumers’ side terroir is still in discussion. Producers have to respect these movements and have to develop strategies how to incorporate those ideas in their production schemes and their marketing activities.

Study of the influence of varietal amino acid profiles on the polyfunctional mercaptans released from their precursors

Polyfunctional mercaptans such as 4-mercapto-4-methyl-2-pentanone, 3-mercaptohexanol and 3-mercaptohexyl acetate contribute strongly to the varietal aroma of wines. These compounds are released during alcoholic fermentation from their precursors and their concentration is strongly linked to the grape variety. The aim of this work was to determine the effect of nine different amino acid profiles of grape varieties on the release of these polyfunctional mercaptans and on the consumption of their precursors as well as to determine which are the preferred precursors. A set-up of fermentations of synthetic must was prepared, which simulated the amino acid profiles of nine different grape varieties, containing known amounts of polyfunctional mercaptan precursors as well as the elements necessary for the yeast metabolism. The yeast assimilable nitrogen was adjusted in percentage to reach 150mgN/L in all the fermentations. Polyfunctional mercaptans and their precursors were analyzed in the final wine by gas chromatography coupled to mass spectrometry with negative chemical ionization and ultrahigh liquid performance chromatography coupled to mass spectrometry, respectively. The results showed significant differences in the release of these polyfunctional mercaptans as well as in the consumption of their precursors according to the amino acid profile. Moreover, it was observed that the preferred precursor of 4-mercapto-4-methyl-2-pentanone was its cysteinylated precursor. These results suggest that the amount of the amino acids as well as the ratio between them could modify the amount of polyfunctional mercaptans released. This could be a tool for the wine industry to vary the aromatic profile of wines by increasing or decreasing these volatile thiols.

Sequential Inoculation of Native Non-Saccharomyces and Saccharomyces cerevisiae Strains for Wine Making.

The use of non-Saccharomyces yeast for wine making is becoming a common trend in many innovative wineries. The application is normally aimed at increasing aromas, glycerol, reducing acidity, and other improvements. This manuscript focuses on the reproduction of the native microbiota from the vineyard in the inoculum. Thus, native selected yeasts (Hanseniaspora uvarum, Metschnikowia pulcherrima, Torulaspora delbrueckii, Starmerella bacillaris species and three different strains of Saccharomyces cerevisiae) were inoculated sequentially, or only S. cerevisiae (three native strains together or one commercial) was used. Inoculations were performed both in laboratory conditions with synthetic must (400 mL) as well as in industrial conditions (2000 kg of grapes) in red winemaking in two different varieties, Grenache and Carignan. The results showed that all the inoculated S. cerevisiae strains were found at the end of the vinifications, and when non-Saccharomyces yeasts were inoculated, they were found in appreciable populations at mid-fermentation. The final wines produced could be clearly differentiated by sensory analysis and were of similar quality, in terms of sensory analysis panelists’ appreciation.

Grape Composition under Abiotic Constrains: Water Stress and Salinity.

Water stress and increasing soil salt concentration represent the most common abiotic constrains that exert a negative impact on Mediterranean vineyards performance. However, several studies have proven that deficit irrigation strategies are able to improve grape composition. In contrast, irrigation with saline waters negatively affected yield and grape composition, although the magnitude of these effects depended on the cultivar, rootstock, phenological stage when water was applied, as well as on the salt concentration in the irrigation water. In this context, agronomic practices that minimize these effects on berry composition and, consequently, on wine quality must be achieved. In this paper, we briefly reviewed the main findings obtained regarding the effects of deficit irrigation strategies, as well as irrigation with saline water, on the berry composition of both red and white cultivars, as well as on the final wine. A meta-analysis was performed using published data for red and white varieties; a general liner model accounting for the effects of cultivar, rootstock, and midday stem water potential was able to explain up to 90% of the variability in the dataset, depending on the selected variable. In both red and white cultivars, berry weight, must titratable acidity and pH were fairly well simulated, whereas the goodness-of-fit for wine attributes was better for white cultivars.

Trained and consumer panel evaluation of sparkling wines sweetened to brut or demi sec residual sugar levels with three different sugars

The dosage liquid, added at the final stage of sparkling wine production, imparts residual sweetness to the wine. No study has yet analyzed the influence of dosage composition on the final wine's sensory profile or consumer acceptance. In this study, dosage composition was altered through the addition of different sugar types (ST; fructose, glucose, or sucrose) to produce seven sparkling wines of varying residual sugar levels (RSL), including no sugar added, brut (5.3–8.4gST/L) or demi sec (34.9–37.8gST/L). As evaluated by a trained panel (n=9), the interaction between ST and RSL influenced the perception of caramelized/vanilla/honey (CVH) flavor, sweet taste, and sour taste attributes (p<0.05). Demi sec wines displayed lower intensities of green flavor, yeasty flavor, and sour taste compared to the no sugar added wine (p<0.05). Consumers (n=126) also evaluated the sparkling wines and ST, RSL, and their interaction influenced consumer acceptance of different attributes, as well as the perception of the “refreshing” aspect of the wine (p<0.05). Overall consumer acceptance of sparkling wines was highly correlated (r2≤0.88) to CVH, floral, and fruity flavors, as well as sweet taste and creamy mouthfeel. External preference mapping revealed two clusters of consumers. Both consumer clusters liked wines sweetened with fructose, but Cluster 1 liked the demi sec sparkling wine sweetened with fructose (32.8g/L fructose) while Cluster 2 preferred the brut wine sweetened with fructose (8.4g/L fructose). These results suggest that consumer preference for sparkling wine was segmented based on sweetness preference. The results of this study offer winemakers knowledge about the influence of dosage composition on the sensory profile of sparkling wine.

The production and consumer perception of sparkling wines of different carbonation levels

ABSTRACTThe objective of this study was to determine the influence of carbonation level on the sensory and chemical properties of traditional sparkling wine and identify the level of carbonation that could be perceived by consumers. Sparkling wine treatments (n = 11) were produced through the addition of different concentrations of dextrose at bottling to create sparkling wines varying in carbonation (CO2) level. Final wines ranged in CO2 concentration from 0 to 7.5 g CO2/L (p ≤ .05). A consumer sensory evaluation panel (n = 48) evaluated the wines using a paired comparison test in which a sparkling wine at CO2 concentrations of 1.2, 2.0, 4.0, 5.8, or 7.5 g CO2/L was compared to the control sparkling wine (0 g CO2/L) for mouthfeel attributes (carbonation and bite) and sour taste. Results showed significant differences (p ≤ .001) between the control and sparkling wines containing 2.0, 4.0, 5.8, and 7.5 CO2/L for the mouthfeel attributes of carbonation and bite, suggesting that a minimum CO2 concentration of >1.2 g CO2/L was required for consumers to detect mouthfeel differences compared to the control. The results of this study provide sparkling winemakers and manufacturers of other carbonated products with information regarding the level of CO2 perceived by consumers of sparkling wines.

Effect of Temperature on the Prevalence of Saccharomyces Non cerevisiae Species against a S. cerevisiae Wine Strain in Wine Fermentation: Competition, Physiological Fitness, and Influence in Final Wine Composition.

Saccharomyces cerevisiae is the main microorganism responsible for the fermentation of wine. Nevertheless, in the last years wineries are facing new challenges due to current market demands and climate change effects on the wine quality. New yeast starters formed by non-conventional Saccharomyces species (such as S. uvarum or S. kudriavzevii) or their hybrids (S. cerevisiae x S. uvarum and S. cerevisiae x S. kudriavzevii) can contribute to solve some of these challenges. They exhibit good fermentative capabilities at low temperatures, producing wines with lower alcohol and higher glycerol amounts. However, S. cerevisiae can competitively displace other yeast species from wine fermentations, therefore the use of these new starters requires an analysis of their behavior during competition with S. cerevisiae during wine fermentation. In the present study we analyzed the survival capacity of non-cerevisiae strains in competition with S. cerevisiae during fermentation of synthetic wine must at different temperatures. First, we developed a new method, based on QPCR, to quantify the proportion of different Saccharomyces yeasts in mixed cultures. This method was used to assess the effect of competition on the growth fitness. In addition, fermentation kinetics parameters and final wine compositions were also analyzed. We observed that some cryotolerant Saccharomyces yeasts, particularly S. uvarum, seriously compromised S. cerevisiae fitness during competences at lower temperatures, which explains why S. uvarum can replace S. cerevisiae during wine fermentations in European regions with oceanic and continental climates. From an enological point of view, mixed co-cultures between S. cerevisiae and S. paradoxus or S. eubayanus, deteriorated fermentation parameters and the final product composition compared to single S. cerevisiae inoculation. However, in co-inoculated synthetic must in which S. kudriavzevii or S. uvarum coexisted with S. cerevisiae, there were fermentation performance improvements and the final wines contained less ethanol and higher amounts of glycerol. Finally, it is interesting to note that in co-inoculated fermentations, wine strains of S. cerevisiae and S. uvarum performed better than non-wine strains of the same species.

Effect of non-Saccharomycesyeasts on the volatile chemical profile of Shiraz wine

Background and Aims This study evaluated the impact that the non-Saccharomyces yeasts, Torulaspora delbrueckii (TD), Lachancea thermotolerans (LT), Pichia kluyveri (PK), Metschnikowia pulcherrima (MP), Candida zemplinina (CZ) and Kazachstania aerobia (KA), in sequential inoculation with Saccharomyces cerevisiae (SC), had on the volatile chemical profile of Shiraz wine. Methods and Results Shiraz grape must was inoculated with monocultures of the non-Saccharomyces yeasts, which were allowed to ferment until 2% v/v ethanol concentration was reached at which point, SC was added to complete the alcoholic fermentation. The control was SC in monoculture. The final wines were subjected to solid phase microextraction-GC × GC-time of flight-MS to evaluate the untargeted volatile metabolite profile of each treatment. Each fermentation produced a unique chemical profile. The LT–SC sequential fermentation was the most significantly different from the control primarily in the ester, alcohol and terpene profile. The KA–SC sequential fermentation had the highest amount of volatile acidity, and the PK–SC sequential fermentation had a relatively high amount of acetaldehyde and a few esters. The MP–SC sequential fermentation also revealed a higher concentration of several esters. The TD–SC sequential fermentation was notable for its lack of a distinct pattern in comparison with that of the other fermentations. Conclusions Given these characteristics, the LT–SC sequential fermentation showed the most potential for increased chemical complexity of the Shiraz volatile profile. Significance of the Study The results demonstrate that there is no clear, singular trend for how different, non-Saccharomyces species of yeast – once thought to be wholly unfavourable in wine fermentations – will impact wine chemistry, flavour or quality. Each species presents unique metabolic characteristics, many of which could be beneficial, and their potential application in the wine industry should be considered.

Postharvest ozone fumigation of Petit Verdot grapes to prevent the use of sulfites and to increase anthocyanin in wine

Background and Aims The request by the consumer for safer food is also pushing the wine sector to find alternative solutions to sulfur dioxide. The aim of this research has been to evaluate the application of ozone as a sanitising agent of grapes before vinification in order to avoid the use of sulfur dioxide. Methods and Results Postharvest ozone fumigation overnight of Petit Verdot grapes increased anthocyanin concentration by 19% versus 9% in the Control (untreated) during fermentation/maceration. Fermentation kinetics were faster in wine made from ozone-treated grapes (16 vs 21 days for the Control), and extraction of phenolic substances and anthocyanin was more rapid than that in the Control wines, Ozone treatment significantly reduced the count of Saccharomyces cerevisiae and non-Saccharomyces yeasts but also significantly decreased the acetic acid bacteria. The final wine produced from ozone-treated grapes was characterised by low volatile acidity (similar to that of the Control wine) with a significant reduction in sulfur dioxide (17 and 8 mg/L, respectively, total and free sulfur dioxide). Sensory evaluation revealed a strong fruity aroma. Conclusions Ozone gas treatment of grapes reduced the microbial count significantly and increased the extraction of phenolic substances and the aroma of the final wine. Significance of the Study Postharvest ozone fumigation can be used to produce wine without sulfur dioxide.

Influence of Winemaking Processing Steps on the Amounts of (E)-2-Decenal and Tridecane as Off-Odorants Caused by Brown Marmorated Stink Bug (Halyomorpha halys).

Brown marmorated stink bugs (BMSB) release stress compounds, tridecane and (E)-2-decenal, that affect final wine quality. This study focuses on determining the effect of wine processing on (E)-2-decenal and tridecane release in both red and white wines. Wines were produced by adding live BMSB to grape clusters at densities of 0, 0.3, 1, and 3 bugs/cluster. Compound concentrations were measured using headspace solid phase microextraction with multidimensional gas chromatography and mass spectrometry. For red wines, the highest levels of stress compounds were found using 3 BMSB/cluster [tridecane, 614 μg/L; (E)-2-decenal, 2.0 μg/L]. Pressing was found to be the critical process point for stress compound release, and additional pressing processes, press types, and press fractions were investigated. BMSB taint for white wines was not found to be problematic with respect to wine quality. An action control of 3 BMSB/cluster is recommended as this was related to the known consumption rejection threshold for (E)-2-decenal.

Targeting Demalication and Deacetification Methods: The Role of Carboxylic Acids Transporters

As weak organic acids, carboxylic acids partially dissociate in aqueous systems, like wine, establishing equilibrium between uncharged molecules (undissociated form) and their anionic form, according to the medium pH and their pKa. This property influences yeasts cell-behaviour, particularly the mechanisms by which the molecules can cross biological membranes. Occasionally wines may present an excessive amount of organic acids. In the mouth they will seem unbalanced and sometimes excessive sourness diminishes their quality. Moreover, these acids originated from grapes or from the fermentation process itself, negatively affect wine yeasts, yeast fermentation process and the final wine quality. Two of those acids are L-malic acid and acetic acid. The first one affects the wine mainly in his tastiness, making it much to sour; the second one, being a volatile compound, besides the excessive sourness, also imprints the wine with an unpleasant vinegar flavour. One approach to solving this problem is biological deacidification by Saccharomyces and non-Saccharomyces wine yeasts. To these biological processes of wine acidity bio-reduction we can call wine bio-demalication (malic acid bio-degradation) and wine biodeacetification (acetic acid consumption by yeasts).

Selection and Characterisation of Oenococcus oeni and Lactobacillus plantarum South African Wine Isolates for Use as Malolactic Fermentation Starter Cultures

This study focused on characterising 23 Oenococcus oeni and 19 Lactobacillus plantarum strains isolated from the South African wine environment for the development of potential commercial malolactic fermentation (MLF) starter cultures. These strains were characterised with regards to oenological important characteristics, including the genetic screening for enzyme-encoding genes (enzymes that are involved/implicated in wine aroma modification, as well as enzymes pertaining to the wholesomeness of the final wine product), their fermentation capabilities, the ability to maintain viability during MLF, as well as the volatile acidity production. A total of three O. oeni and three L. plantarum strains were selected at the completion of this study. These six strains showed the most potential during the characterisation stages of the study and were able to successfully complete MLF in Pinotage wine. It was also found that L. plantarum strains displayed a more diverse enzyme profile than O. oeni strains, particularly with regards to the presence of the aroma-modifying enzymes β-glucosidase and phenolic acid decarboxylase (PAD), which implies the future use of this species in the modification of the wine aroma profile and use as commercial starter culture.

The effects of flash release conditions on the phenolic compounds and antioxidant activity of Pinot noir red wine

This study investigated the effects of a flash release versus traditional maceration expansion on the content of phenolic compounds (by LC–MS, UPLC–PDA), antioxidant activity (ABTS and FRAP), and other physical and chemical properties of wine from Pinot noir cultivar. The content of polyphenols in a must obtained by the flash release technology was higher than when using a traditional method. Flash release expansion improved the extraction of polyphenol compounds, especially anthocyanins, as well as color properties and antioxidant activity. However, during maturation and storage, the content of polyphenols significantly decreased, especially in the wine exposed to the flash release expansion. Despite lower total polyphenols content (1435 vs. 1686 mg/L in control), the final flash release wine contained more anthocyanins which resulted in approximately 2 times higher antioxidant activity. High correlation between antioxidant activity (r2 = 0.84 and 0.79 for ABTS and FRAP assay, respectively) and the content of anthocyanins was determined in both types of examined wines. Changes in color were also observed in the must prepared by flash release versus traditional maceration. During fermentation, L* and a* parameters, the variables associated with more light and red color, increased, and during maturation, a rise in b* parameter, associated with yellow color, was observed.

Use of Visible and Short-Wave Near-Infrared Hyperspectral Imaging To Fingerprint Anthocyanins in Intact Grape Berries.

In red grape berries, anthocyanins account for about 50% of the skin phenols and are responsible for the final wine color. Individual anthocyanin levels and compositional profiles vary with cultivar, maturity, season, region, and yield and have been proposed as chemical markers to differentiate wines and to provide valuable information regarding the adulteration of musts and wines. A fast, easy, solvent-free, nondestructive method based on visible, short-wave, and near-infrared hyperspectral imaging (HSI) in intact grape berries to fingerprint the color pigments in eight different grape varieties was developed and tested against HPLC. Predictive models based on modified partial least-squares (MPLS) were built for 14 individual anthocyanins with coefficients of determination of cross-validation (R2CV) ranging from 0.70 to 0.93. For the grouping of total and nonacylated anthocyanins, external validation was conducted with coefficient of determination of prediction (R2P) of 0.86. HSI could potentially become an alternative to HPLC with reduced analysis time and labor costs while providing reliable and robust information on the anthocyanin composition of grape berries.

Integrative Effects of Vine Water Relations and Grape Ripeness Level of Vitis vinifera L. cv. Shiraz/Richter 99. II. Grape Composition and Wine Quality

Regulation of grapevine water status is a common practice to manipulate grape composition and wine quality. In this investigation the effect of plant water status (two field water capacity-based irrigation levels, 75% and 100%, applied at single and combined vine developmental stages) and ripeness level (harvesting at different soluble solid levels) on grape composition and wine quality of Vitis vinifera L. cv. Shiraz/ Richter 99 was determined. Integrative effects of vine water relations and grape ripeness level, specifically in a Mediterranean high winter rainfall area, have not yet been investigated systematically. Source:sink mechanisms and dynamics and compositional and physical changes during both green berry and ripening periods (and in response to environment changes), seemed critical for the final grape composition and wine quality/style. Despite relatively favourable conditions of the experiment terroir, additional water was still required to obtain best grape and wine quality. Skin colour and total phenolic contents were stimulated in particular by 75% (field water capacity) pea size (PS) irrigation, post-veraison (PV) irrigation and 75% pea size+post-veraison irrigation, until the last harvest stage. Treatments that included post-veraison irrigation were not negative in terms of ripening parameters. Increasing total soluble solids with ripening were not followed in parallel by anthocyanin potential. Anthocyanin extractability increased with ripening. A late, overripe harvest may result in wines that are slightly better coloured, but highly alcoholic and tannic. Furthermore, at high ripeness level, differences between treatments largely diminished. Over-ripeness of grapes may have tempering and even negative effects on expected outcomes of seasonal cultivation efforts to produce unique wines. This would not favour economic viability. Although non-irrigated wines failed to result in exceptional wine quality at any harvest stage, a better result in overall quality was obtained in comparison to irrigation treatments applied at all stages. Berry and wine composition results corresponded with findings on wine sensorial quality. The 75% PS, PV irrigation, and 75% PS+PV irrigation consistently resulted in good quality wines. At the first harvest stage, 75% PV, 100% PV, 75% PS+V and 75% PS+PV irrigations gave most prominent wines; at the second harvest stage, vines irrigated 75% at PS, 75% at PS+PV and 75% at PV delivered most prominent wines; and at the third harvest stage, 75% PV, 100% PV, 75% PS and 75% PS+PV resulted in most prominent wines. These treatments represented different wine styles at each harvest stage. Restricted PS irrigation and PV irrigation, as single or combined treatments, featured prominently in favouring grape and wine composition and wine sensorial quality. Physical and compositional changes in ripening berries and the impact on wine quality and style were further clarified. New perspectives on managing time of harvesting with varying vine water status are given. Recommendations on vine water status management strategies required to obtain different grape composition and wine style are made.

Interannual climatic variability effects on yield, berry and wine quality indices in long-term deficit irrigated grapevines, determined by multivariate analysis

Interannual climatic variability effects on yield, berry and wine quality indices in long-term deficit irrigated grapevines, determined by multivariate analysis Pascual Romero,1 Jose Ignacio Fern&aacute;ndez-Fern&aacute;ndez,2 Pablo Bot&iacute;a1 1Department of Natural Resources, Irrigation Group and Physiology of Stress, 2Department of Viticulture, The Murcian Institute of Agri-Food Research and Development (IMIDA), Murcia, Spain Abstract: The effects of climatic factors on yield and berry and wine quality for long-term (7&nbsp;years) deficit-irrigated (DI) Monastrell wine grapes under the semiarid conditions of southeast Spain were analyzed. The relationships between climatic variables and the yield, and novel technological berry quality (QItechnologicalberry), phenolic berry quality (QIphenolicberry), overall berry quality (QIoverallberry), and wine quality (QIwine) indices confirmed that the most important climatic factors were rainfall, temperature, and radiation. Climate was more influential in determining yield, berry, and wine composition in some important physiological periods such as early season (budburst&ndash;fruit set) and ripening (v&eacute;raison&ndash;harvest). In general, climate had more influence on berry quality than on wine quality indices and greater QIoverallberry was also reflected in greater QIwine. According to the stepwise multiple regression, the best fitted models for the partial root-zone drying irrigation (PRI) system were less complex (with a lower number of climatic variables) than for the regulated deficit irrigation (RDI) system, suggesting that PRI is less influenced by climatic factors than RDI. For PRI, the models for yield, berry and wine quality were explained by three climatic factors (rainfall, T&ordf;, and radiation), whereas for RDI, more climatic factors came into play (number of hours of sunshine, evapotranspiration, and vapor pressure deficit). According to these models, in RDI, a sunny and drier pre-v&eacute;raison period followed by higher soil water availability and associated greater crop evapotranspiration during ripening favored final berry and wine quality. In contrast, in PRI, greater rainfall during the growing season and greater solar radiation during ripening were the main climatic factors that positively influenced the yield response, berry and wine quality. Besides, berry quality in PRI was more affected (negatively) by high temperatures (high T&ordf;max and T&ordf;min) during the growing season than in RDI and SDI, indicating that cooler and humid years may favor the PRI response more. These results suggest that years with a cool, wet winter followed by a mild, wet spring and early summer (April&ndash;June) and a mild fruit set&ndash;v&eacute;raison period (June&ndash;July), and then greater solar radiation during ripening (August&ndash;mid-September) provide adequate growth potential and increase the likelihood of higher berry and wine quality in PRI. Besides, more irrigated SDI vines were less sensitive to high temperatures and low soil water content during ripening than RDI and PRI vines. Keywords: berry quality indices, climatic factors, multivariate analysis, deficit irrigation techniques, wine quality index, yield

Pinot noir wine volatile and anthocyanin composition under different levels of vine fruit zone leaf removal

The impacts of fruit zone leaf removal on volatile and anthocyanin compositions of Pinot noir wine were investigated over two growing seasons. Wine volatiles were analyzed by multiple techniques, including headspace solid phase microextraction-GC-MS (HS-SPME-GC-MS), headspace-GC-FID (HS-GC-FID) and stir bar sorptive extraction-GC-MS (SBSE-GC-MS). Fruit zone leaf removal affected the concentration of many grape-derived volatile compounds such as terpene alcohols and C13-norisoprenoids in wine, although the degree of impact depended on the vintage year and severity of leaf removal. Fruit zone leaf removal resulted in greater concentrations of linalool, α-terpineol and β-damascenone but had no impact on other terpene alcohols or β-ionone. Fruit zone leaf removal had no consistent impact on C6 alcohols, volatile phenols, lactones, fermentation-derived alcohols, acids, or most esters. Fruit zone leaf removal increased anthocyanins in final wine.

Partial dealcoholization of red wine by nanofiltration and its effect on anthocyanin and resveratrol levels.

The present work studies the use of nanofiltration for the production of red wine concentrate with low alcohol content. Factorial design was applied to measure the influences of transmembrane pressure (10-20 bar) and temperature (20-40 ℃) on the retention of valuable components such as anthocyanins and resveratrol, and on the nanofiltration membrane performance. The highest retention of anthocyanin and resveratrol was achieved at low temperature (20 ℃), while the high transmembrane pressure (20 bar) was found to increase the permeate flux considerably. The experiments demonstrated that nanofiltration appears as a valid technique for the production of low alcohol content red wine concentrate. Reduction of volume by a factor of 4, leads to 2.5-3 times more anthocyanins and resveratrol in the wine concentrates. The final new wine products - obtained by using various forms of reconstitution of the concentrated wine - had low alcohol content (4-6 % by volume) and their sensory attributes were similar to those of the original wine.