Experimental Wines Research Articles

New insights about sensory contribution of grape stems during winemaking: role of astilbin, a sweet polyphenol

In the usual red winemaking process, grapes are destemmed between the harvest and the filling of the vat. However, in regions like Bourgogne, some winemakers let all or a part of the stems in contact with the juice during vatting. This choice will likely affect the sensory properties of wine, such as its gustatory perception. The present study investigated the effect of adding stems during the winemaking process on the concentration of a sweetening compound, astilbin. The sensory contribution of astilbin in wines was first clarified by measuring its taste detection threshold and comparing it with the concentrations found in various commercial wines. Then, experimental wines resulting from the addition of stems in various proportions were analysed. These practical experiments were carried out in various French wine estates, in Bourgogne, Beaujolais and Bordeaux, over three vintages, allowing the comparison of different grape varieties, namely Pinot noir, Gamay and Merlot. For each experiment, the modality with the addition of stems was compared with a vat of destemmed grapes from the same plot. Samples were taken throughout the winemaking process to be analysed by liquid chromatography coupled with high-resolution mass spectrometry (UHPLC-Exactive, Orbitrap analyser). The results showed that the addition of stems during vatting significantly increased astilbin concentration. Furthermore, this increase varied according to the grape variety. Whereas the astilbin contents were lower in Merlot wines than in Pinot noir or Gamay wines, the ratio between its concentration of wines from the two modalities was higher in Merlot than in Pinot noir and Gamay. The localisation of astilbin in the different components of the bunch, depending on the grape variety, was also investigated to understand this difference better. Thus, a higher abundance of astilbin in stems than in skins was found in the Merlot variety, whereas, for Gamay and Pinot noir, the total quantity of astilbin in a bunch was located in equal proportions in stems and skins. These new results bring new tools to understand better the practice of whole bunch vinification from a chemical perspective.

Influence of Cryoextraction and Cold Pre-Fermentative Maceration on the Yeast Microbiota and the Volatile Compounds Profile of Sangiovese Wine

Low-temperature treatments can be applied to grapes or must before alcoholic fermentation to enhance the wine’s sensory characteristics. Several studies have shown that such practices have a positive effect on the polyphenol profile of the wine, but only a few surveys have examined the effect of these treatments on the yeast microbiota of grapes and wine. Therefore, this study aimed to evaluate how cryoextraction (freezing the grape with liquid nitrogen) and cold pre-fermentative maceration (at 5 °C for 48 h) affect the Saccharomyces and non-Saccharomyces populations during the winemaking process of red grapes, cv Sangiovese, conducted at two temperatures (20 and 30 °C). This research analyzed the concentration of various yeast species, their fermentation abilities, and the resulting wine’s aromatic profile. The Principal Component Analysis performed on yeast concentrations during the fermentations of various wines did not group the experimental wines based on treatment. However, the same groupings were highlighted when the concentrations of the volatile compounds, quantified in the experimental wines, were processed using the same statistical approach. Therefore, cryoextraction and cold pre-fermentative maceration seem to contribute less to the aromatic profile than the yeasts involved in the fermentation process.

Effect of an innovative sorbent material coupled to continuous flow process in the protein and oxidative stability of white wines

In this work the impact of an innovative protein stabilization method (TiO2-based composite sorbent material coupled with a prototype device operating under continuous flow) has been tested in terms of protein and oxidative stability of white wines. Optimal process parameters (duration 60 min; flow rate 1.5 ± 0.1 L/h in 6 cycle rates/h) ensured an average 32.5 % reduction of total proteins; the nanoporous TiO2 film supported on inert glass beads acted as selective sorbent for pathogenesis-related proteins (PRPs, 10–60 kDa) responsible for wine instability, based on the protein stability studies (heat-test) performed in the experimental wines. The stabilization process has been tested for the release of contaminants (Ti), and the innovative treatment has been proven to preserve wine from oxidation also delaying the browning onset under extreme storage conditions.

TaqMan® and HRM approaches for SNP genotyping in genetic traceability of musts and wines

The fight against fraud in the wine sector requires continuous improvements and validations of new technologies applicable to musts and wines. Starting from published data from the Vitis18kSNP array, a series of new specific single nucleotide polymorphism (SNP) markers have been identified for some important north-western Italian cultivars, such as Barbera, Dolcetto and Arneis (Vitis vinifera L.), used in the production of high-quality wines under Protected Denomination of Origin. A pair of new SNP markers for each grape variety were selected and validated using two real-time PCR techniques: TaqMan® genotyping assays and high-resolution melting analysis (HRM). The TaqMan® assay has proven to be more reliable and repeatable than HRM analysis because despite being an economical and versatile technique for the detection of different types of genomic mutations (SNPs, insertions or deletions), HRM has shown limitations in the presence of poor-quality DNA extracted from musts and wines. TaqMan® assays have successfully identified Barbera, Dolcetto and Arneis in their respective musts and experimental wines, and with good efficiency in commercial wines. Marked differences between genotypes were observed, varietal identification in Dolcetto-based musts/wines was more efficient than that in Arneis-based wines. Therefore, the TaqMan® assay has considerable potential for varietal identification in wines and the procedure described in the present work can be easily adapted to all wines with adequate setup of DNA extraction methods that should be adapted to different wines.

Effect of the grape thinning on the content of trans-resveratrol in some Syrah clones

Wine is a product obtained through fermentation process, the trans-resveratrol is a polyphenol derived from grapes and a natural antioxidant that passes into wine. The trans-resveratrol is a rare compound with the highest content in the red wine and a positive physiological effect on human organism. The present study was conducted in three years period from 2020 until 2022 at the Agricultural university-Plovdiv experimental vineyard, located near the village of Brestnik. Four Syrah wine variety clones were included and eight experimental wines have been made during the experimental period. In all tested wines, the presence of trans-resveratrol was detected but its amount was higher in clone 524 (V4) with non-reduced yield (3.35, 4.36, 7.02 mg/L), and in clone 100 (V5) with reduced yield (5.24, 3.75, 7.23 mg/L). Reducing the bunch numbers at the “pea size” stage did not significantly influence the content of trans-resveratrol. The wine antioxidant properties were directly affected by the clone and the grape harvest and was under the terroir influence. In today's conditions of overproduction and increased competition, the results of this study provide a valuable economic information and expand the portfolio of wineries. Keywords: clones, Syrah, red wine, resveratrol, bunch thinning, canopy management

Grapevine stem water potential seasonal curves: response to meteorological conditions, and association to yield and red wine quality

Managing grapevine water status is a key component for achieving optimal yield and wine quality. Stem water potential (SWP) is used for determining the drought stress and is associated with physiological, vegetative, and reproductive processes. SWP seasonal curves (SWP-SCs) represent the seasonal stress levels. SWP-SCs may change within and between growing seasons according to environmental and irrigation factors. The objective was to analyze the temporal dynamics of SWP-SCs, their response to meteorological and irrigation conditions, and their impact on yield and wine quality. A dataset was assembled from a six-year experiment (2014-2019) in a ‘Cabernet Sauvignon’ vineyard, including meteorological features, irrigation treatments, field measurements of SWP, yield components (i.e., yield, number of clusters, cluster weight, and berry mass), and wine-quality scores from experimental wines. Between- and within-seasonal variations of SWP-SCs were assessed using ANOVA and discriminant analysis. The effects of meteorology and irrigation on SWP-SCs were quantified using random forest. Clustering of SWP-SCs was conducted using a fuzzy c-means algorithm and the clusters (groups) were analyzed against yield components and wine quality using ANOVA. Our findings show that the mean seasonal SWP values were significantly different among seasons, while SWP values during the weeks proximal to veraison were the major discriminators. Temperature was a strong driver of SWP, followed by relative humidity and precipitation. Three clusters were generated according to stress levels throughout the season. The moderate-severe stress group (Cluster 2) was associated with similar yield components levels compared to the moderately-stressed group (Cluster 1) and significantly higher wine quality components, with a minimal SWP threshold of -1.5 - -1.6 MPa before harvest. The extreme drought stress group (Cluster 3) was associated with significantly lower yield and wine quality. Increasing temperatures and shifting patterns of precipitation are projected to continue excessively, inducing disruptive conditions to the target vine drought stress levels.

Utilization of the AIRMIXING M.I.™ System in Producing Red Wine without Added Sulphites

Sulphur dioxide (SO2) is usually used in winemaking due to its effectiveness as an antimicrobial and antioxidant agent. However, there is growing interest in finding alternatives to SO2 because of its adverse effects on human health. Therefore, in this work, a low-SO2-producing Saccharomyces cerevisiae strain was selected and the AIR-MIXINGTM M.ITM (A.M.) system, capable of determining a high extraction of polyphenols, was used to produce a red wine without added sulphites. A tank managed with the traditional pumping-over technique was used as a comparison. Microbiological and chemical monitoring of both fermentations performed by plate counts and HPLC analyses, respectively, did not indicate significant differences as regards the yeast growth kinetics and the degradation of the sugars, while it highlighted a faster extraction kinetics of colour and total polyphenols in the fermentation carried out with the A.M. system. Both experimental wines showed a total SO2 content <10 mg/L, but in the wine produced with A.M., a higher content of the polymeric forms of anthocyanins and non-anthocyanin phenols was found in favour of a higher stability of the wine achieved in a shorter time than the control. Furthermore, a higher concentration of reduced glutathione, a compound well-known for its antioxidant activity, occurred in wine obtained with the A.M. system. In conclusion, the use of low-SO2-producing yeasts in combination with the A.M. system could be a suitable approach to produce wines without sulphites added.

ВЛИЯНИЕ БУТЫЛОЧНОЙ ВЫДЕРЖКИ НА СОСТАВ ОРГАНИЧЕСКИХ КИСЛОТ ВИН ИЗ СОРТОВ ВИНОГРАДА ВЕНГЕРСКОЙ СЕЛЕКЦИИ В УСЛОВИЯХ НИЖНЕГО ПРИДОНЬЯ

The aim of the work was to study the influence of bottle aging on the composition of organic acids and organoleptic properties of wines made from white grapevine varieties of Hungarian breeding growing in the Lower Don Region. The objects of the study were dry white wines made from grapevine varieties of Hungarian breeding − Bianca, Lakhedyi mesesh, Crystal, control − Aligote (Vitis vinifera L.), aged in a bottle from 1 to 3 years in the oenoteca of the Institute. The studies showed that during 3 years of aging the total content of organic acids (sum) decreased by 0.35−2.41 g/dm3. The largest decrease in the amount of organic acids was noted in the experimental wines from the variety Bianca (by 2.41 g/dm3). In the experimental wines the total amount of tartaric and malic acids was 56,8−76,3% of all the acids in the wine and decreased in the wines from variety Aligote (control) − by 11.2 %; Bianca − by 18.6 %; Lakhedi Mezesh − by 10,2 %; Kristall − by 7 % as it was aged in the bottle. The greatest decrease in tartaric acid concentration was observed in experimental wines of Bianca variety (by 2.4 g/dm3). In all the experiments the concentrations of succinic acid (by 13.3−28.3 %) and citric acid (by 20−38 %) decreased. The change of succinic acid content in the wines from Aligote variety (control) occurred after 2 years of aging in bottle, and of citric acid after 3 years of aging. In wines from varieties of Hungarian breeding (Bianca, Lakhedy Mesz, Crystal) it was observed that the change of citric acid content occurred after 2 years of aging and of amber acid content after 3 years. As a result of the organoleptic analysis it was determined that the highest tasting scores were given to Aligote (Control) (8,7−8,9 points) and Lakheddi mezesz (8,6−8,7 points), these wines during 3 years long aging had a bright varietal aroma, and more over their bouquet has improved, they have a light harmonious taste with a long pleasant aftertaste.

EVOLUTION OF CIS AND TRANS-RESVERATROL IN WINES OBTAINED THROUGH INOCULATION WITH ACTIVE DRY YEAST AT PIETROASA VINEYARD

This paper presents the results of the testing during the winemaking process using commercial active dry yeasts (CADY) in parallel with yeast biomass produced starting from yeasts isolated from Pietroasa area (Romania) (PAY). PAYs were obtained based on autochthonous yeasts isolated from Busuioacă de Bohotin (BB) and Tămâioasa Românească (TR) grape varieties. Two variants of must for each grape variety were taken in study, i.e. obtained from early harvested grapes (TRD and BBD) and from late harvested grapes (TRS and BBS). Winemaking experiments were carried out with 7 types of commercial yeasts and two types of commercial nutrients. The alcoholic concentration of the experimental wines varied from 11.8 % for WTRD to 18.4% for WBBD. The WBBD & S samples showed a higher average trans-resveratrol content (1.716 and 1.555 mg/L, respectively) compared to the WTRD & S wine samples (0.590 and 1.365 mg/L, respectively). The variation in the cis-resveratrol content between the experimental variants produced with PAY was not significant.

Management of in-Amphora "Trebbiano Toscano" Wine Production: Selection of Indigenous Saccharomyces cerevisiae Strains and Influence on the Phenolic and Sensory Profile.

The use of earthenware amphorae in winemaking can give wines unique attributes enhancing their typicity. Therefore, in this study, spontaneous and inoculated in-amphora fermentations of Trebbiano Toscano grape must were monitored to assess the Saccharomyces cerevisiae strains occurring in each fermentation as well as the chemical characteristics of the wines. Strain typing via Interdelta analyses pointed out that the commercial starters did not dominate, showing 24% and 13% implantation percentages, and that 20 indigenous strains were present at different percentages, ranging from 2 to 20%, in inoculated and spontaneous fermentations. The assessment of the technical characteristics of the indigenous strains via fermentations at lab and pilot scale (20 L amphorae) and the sensory analysis of the experimental wines allowed for the selection of two indigenous strains to be used as starter cultures in comparison to a commercial strain in 300-L-amphorae vinifications in the cellar. The observed fermentative performances and sensory analysis of the experimental wines highlighted that one indigenous S. cerevisiae strain dominated the process and conferred distinctive sensory characteristics to the Trebbiano Toscano wine, demonstrating its effectiveness in managing the in-amphora fermentations. In addition, the results demonstrated the ability of amphorae to protect the polyphenolic compounds from oxidation during wine ageing. Indeed, the concentration of both hydroxycinnamic acids and flavonols decreased, with an average reduction of 30% and 14%, respectively, while hydroxybenzoic acids remained unchanged.

Color Characterization of Bordeaux Red Wines Produced without Added Sulfites.

Nowadays, the development of naturalness as a concept is illustrated in the oenological field by the development of wine produced with lower inputs, sometimes even without any addition of SO2 throughout the winemaking process, up to the bottling stage. Despite the increase in the offer of these wines, they remain poorly explored in the literature and require characterization. This study was developed to evaluate the color of Bordeaux red wines without SO2 addition using colorimetric and polymeric pigments analysis. From a batch of commercial Bordeaux red wines with and without SO2 addition, and experimental wines produced from homogenous grapes according to different winemaking processes, colorimetric analyses (CIELab and color intensity (CI)) revealed a large difference in wine color depending on the presence or absence of SO2. Indeed, wines without SO2 were significantly darker and presented with a deeper purplish color. According to these observations, polymeric pigments were quantified using UPLC-DAD/ESI QTof, and a higher concentration of polymeric pigments bound by the ethylidene bridge was observed in wines without SO2. This correlated with differences observed for CIELab and CI. Finally, a comparison with polymeric tannins bound by ethylidene bridge was made and revealed that no differences were observed between wines with and without added SO2. This underlines the affinity difference between tannins and anthocyanins to react with acetaldehyde to form ethylidene bridges.

Dimethyl Sulfide (DMS) in Amarone Wines: Influence of Aging, Withering, Grape Variety, and Geographical Origin.

Occurrence of dimethyl sulfide (DMS), a potent aroma compound accumulating during aging, was investigated in commercial and experimental Amarone wines. In commercial Amarone, DMS was observed in concentrations ranging from 2.9 to 64.3 μg/L. Model aging studies on experimental wines indicated that DMS in Amarone is strongly associated with aging and that wines from different vineyards can vary significantly in their ability to accumulate DMS during aging. The capacity of certain vineyards to give wines with higher DMS-forming potential was consistent across three consecutive vintages, representing a true terroir factor to be expressed with aging. Wine content of primary amino acids (PAN), a commonly analyzed enological parameter of grape must, was shown to be positively correlated with DMS accumulation during aging. Grape withering also increased DMS-forming potential mostly due to increased PAN resulting from concentration due to water loss. Increased pH due to withering also contributed to a higher DMS content of withered wines, but to a lower extent. In certain vineyard sites, an influence of vintage conditions on DMS-forming potential was also observed.

Benzothiadiazole Affects Grape Polyphenol Metabolism and Wine Quality in Two Greek Cultivars: Effects during Ripening Period over Two Years.

Grape berries are one of the most important sources of phenolic compounds, either consumed fresh or as wine. A pioneer practice aiming to enrich grape phenolic content has been developed based on the application of biostimulants such as agrochemicals initially designed to induce resistance against plant pathogens. A field experiment was conducted in two growing seasons (2019-2020) to investigate the effect of benzothiadiazole on polyphenol biosynthesis during grape ripening in Mouhtaro (red-colored) and Savvatiano (white-colored) varieties. Grapevines were treated at the stage of veraison with 0.3 mM and 0.6 mM benzothiadiazole. The phenolic content of grapes, as well as the expression level of genes involved in the phenylpropanoid pathway were evaluated and showed an induction of genes specifically engaged in anthocyanins and stilbenoids biosynthesis. Experimental wines deriving from benzothiadiazole-treated grapes exhibited increased amounts of phenolic compounds in both varietal wines, as well as an enhancement in anthocyanin content of Mouhtaro wines. Taken together, benzothiadiazole can be utilized to induce the biosynthesis of secondary metabolites with oenological interest and to improve the quality characteristics of grapes produced under organic conditions.

The influence of the vine rootstock on the agrobiological and technological characteristics of the Kaylashki Rubin variety

The rootstock had a significant impact on the quantity and quality of grapes of the varieties grafted on it. That had been determined by the different growth strength of the rootstocks, their different absorption capacity and compatibility with the cultivated vine. During the period 2017-2020, a study was carried out on the agrobiological and technological properties of grapes and wine of the Kaylashki Rubin variety, grafted on vine rootstocks SО4, 110 Rihter, 44-53 Malegue and Fercal. Differences in the investigated indicators were found as a result of the influence of the used rootstocks. A mechanical analysis was made to determine the composition and structure of the clusters and berries. For the period, the highest average yield per vine was reported for Fercal rootstock, while the best theoretical yield had the variant on 44-53 Malegue rootstock. The chemical composition of grapes and experimental wines had been determined. On the average for the period the highest sugar accumulation and respectively the lowest titratable acids in grapes were reported in the variant of 44-53 Malegue rootstock. The opposite relationship was observed for 110 Richter. Differences in the chemical composition of the wines depending on the used rootstocks were found. The wines from 44-53 Malegue variant had the highest average alcohol content and sugar-free extract, but the lowest rates of titratable acids. The average amounts of the total phenolic compounds and anthocyanins in the wines from the variants of the different rootstocks were close. Their values were the lowest in the samples 2017 vintage. The rootstock type also affected the organoleptic properties of the Kaylashki Rubin wines; however, there was no common trend for the studied period. In 2018 and 2020, the samples from the 110 Rihter variant showed the best tasting qualities.

Methyl Salicylate, an Odor-Active Compound in Bordeaux Red Wines Produced without Sulfites Addition

Red wines produced without the addition of any SO2 are currently the source of a new consumer trend. The first characterization approaches regarding these specific wines were devoted to sensory studies that highlighted differences according to the use of SO2 during winemaking. The goal of this paper is to extend our knowledge of such aromatic specificities. Examining experimental wines produced with and without the addition of SO2, aroma fractionation, gas chromatography coupled with olfactometry, and mass spectrometry were applied to identify compounds at the origin of the specificities of these wines. Thus, we identified methyl salicylate as being impacted by the use of SO2 during the winemaking process. Studying a large number of commercial Bordeaux red wines, methyl salicylate was significantly quantified at a higher content in wines without added SO2. A sensory approach revealed a significant impact of methyl salicylate on wines without the sulfite aroma, particularly concerning fruity aromas and wine freshness.

ОСОБЕННОСТИ СОСТАВА ОРГАНИЧЕСКИХ КИСЛОТ СУСЕЛ И ВИН ИЗ КРАСНЫХ СОРТОВ ВИНОГРАДА МЕЖВИДОВОГО ПРОИСХОЖДЕНИЯ

The aim of the work was to study the composi-tion of organic acids of musts and wines made from red grapevine varieties of interspecific origin growing in the conditions of Rostov re-gion. The objects of the study were must and wines prepared under conditions of micro winemaking from red grapevine varieties of interspecific origin bred by ARRIV&W, a branch of FSBSI FRASC ‒ Denisovsky, Cab-ernet Severniy, Augusta, Cabernet Sauvignon (control), according to the classical technology adopted for red dry wines. As a result of the study the following results were obtained. In must of all studied varieties the predominance of tartaric acid over malic acid was observed in several times, while in the interspecific grape-vine varieties the concentration of tartaric acid was 5‒6 times higher than malic acid, while in the control only 2.5 times higher. The greatest amount of tartaric acid was observed in the must from Cabernet Severniy grapes ‒ 5.6 g/dm3. Malic acid accumulation was signifi-cantly lower in all variants (0.48‒1.1 g/dm3) compared with the control Cabernet Sauvignon (2 g/dm3). There was a slight accumulation of succinic acid in the must from Denisovsky and Cabernet Severniy grapes. In all variants, with the exception of Augusta wine, the concentra-tion of tartaric and malic acids decreased. The total proportion of tartaric and malic acids in the experimental wines was 38‒74.7 % of all acids in wine. The highest concentration of succinic acid was observed in wines from Den-isovsky and Cabernet Sauvignon varieties.

Influence of Wine pH and Ethanol Content on the Fining Efficacy of Proteins from Winemaking By-Products.

Wine color and limpidity are important aspects of consumer preferences. The alteration of these parameters can damage wine’s appearance but also its mouthfeel characteristics due to its relationship with attributes such as bitterness and astringency. Fining is a practice usually used in enology to modulate undesirable wine organoleptic attributes. However, there are several factors that influence this technique. In this study, the influence of wine pH and ethanol content on grape seed protein fining efficacy has been assessed. Wine clarification, total phenolic and flavanol contents, antioxidant activity, and chromatic parameters have been investigated before and after fining process. The most noticeable clarifying effects were observed for the experimental wines with a lower pH and ethanol content. Control of these factors will make it possible to modulate the main organoleptic properties of the wine, also avoiding the addition of large amounts of fining agents and thus providing greater versatility to wineries during winemaking. Furthermore, our findings indicated that grape seed protein is a potential alternative to other plant-based fining proteins commonly used in winemaking. Its effects on clarification and color quality have been found to be comparable to those of potato protein and significantly better than those of pea protein.

Study of the effect of some herbicides on the volatile composition of red wines from Cabernet sauvignon

Gas chromatographic study (GC-FID) to determine the volatile composition of wines (two harvests - 2018 and 2019) of the Cabernet Sauvignon variety with the treatment of experimental plantations with herbicides Pledge 50 WP (flumioxazin), Lumax 538 SC (s-metolachlor + terbuthylazine + mesotrione) and Guild (pyraflufen-ethyl + glyphosate) was performed. The results were compared with untreated control. The wines of the 2018 harvest showed a higher total content of volatile compounds compared to the 2019 harvest. Herbicide treatment had the effect of increasing the content of higher alcohols in the experimental wines. This was a possible effect of blocking competition for nutrients needful for the vine metabolism by weeds elimination. The wines of the 2018 harvest contain 9 higher alcohols, the main ones were 1-propanol, 2-methyl-1-butanol, 3-methyl-1-butanol and 4-methyl-2-pentanol. The wines from the next harvest showed a poorer species composition of higher alcohols - 5 representatives, with the main presence of 2-methyl-1-butanol and 3-methyl-1-butanol. The experimental variants for the wines of the 2018 harvest showed a higher total ester content compared to the control and the main esters were ethyl acetate and ethyl decanoate. In the next harvest this tendency was absent, and the main representative of the esters was propyl acetate. The aldehyde fraction was represented by acetaldehyde. A low total terpene content in the wines was found, which was normal, as Cabernet Sauvignon is a non-muscat variety. Methyl alcohol concentrations were defined. They were many times lower than the maximum allowable, which characterized wines as toxicologically harmless. The study showed that the treatment with the herbicides Guild, Lumax 538 SC and Pledge 50 WP of experimental plantations of Cabernet Sauvignon led to improved synthesis of higher alcohols and esters in wines, which reflected in improving of their volatile and aromatic quality.

РЕЗУЛЬТАТЫ ИЗУЧЕНИЯ ЭЛЕМЕНТНОГО СОСТАВА И КАЧЕСТВА ВИНОМАТЕРИАЛОВ ИЗ УСТОЙЧИВЫХ СОРТОВ ВИНОГРАДА НОВОГО ПОКОЛЕНИЯ

In recent years, much attention has been paid to the restoration and development of viticulture and winemaking in our country. The state promotes the planting of new vineyards by providing subsidies for for the establishment of vineyards and the care of young plantings. Favorable conditions are created for the competitiveness of domestic winegrowing products. Another vector of agricultural development is the growing popularity of organic farming products farming in the world. The Federal Law No 280-FZ “On Organic Products and on Amendments to Certain Legislative Acts of the Russian Federation” was adopted and entered into force on January 01, 2020. The principles of organic production are increasingly spread in viticulture production. Consequently the cultivation of resistant grape varieties is of great importance, because classic European varieties require repeated pesticide treatments to protect crops and plants from diseases. The purpose of the research is to assess qualitative composition of wine materials of a group of new resistant grape varieties for the production of red wines. The research involved the following resistant wine grape varieties by VCR breeding with red berry color: Merlot Early, Merlot Khorus, Cabernet Volos, Cabernet Eidos. Merlot variety served as the control. The origin of varieties is complex interspecific. The evaluation of the varieties of a new generation was carried out according to the methods generally accepted in viticulture and winemaking. When assessing the elemental composition of wine materials, quantitative parameters of the presence of 27 mineral elements in leaves and wine materials were established. It was found that potassium (1329.0–1877.0 mg/l) is in the first place in terms of content in wine materials, followed by sulfur, calcium, magnesium, silicon, phosphorus, sodium, boron, iron, copper, manganese, zinc. A significant excess of the content in the leaves and wine materials of the control variety compared with the experimental varieties was established by the content of iron, sodium, sulfur, phosphorus. The silicon content was higher in the experimental wine materials.

Schizosaccharomyces japonicus/Saccharomyces cerevisiae mixed starter cultures: New perspectives for the improvement of Sangiovese aroma, taste, and color stability

Schizosaccharomyces japonicus and Saccharomyces cerevisiae were inoculated in Sangiovese grape must and the impact of simultaneous (co-inoculation) and sequential inoculation protocols on growth and fermentation kinetics, and on the analytical and sensory profiles of the experimental wines, was evaluated at the end of the alcoholic fermentation and after aging in bottle.While Sch. japonicus proved to affect S. cerevisiae growth and fermentative performances solely in sequential inoculation, the combined activity of the two yeasts always resulted in significantly higher total polysaccharides concentrations (p < 0.05), no matter the inoculation protocol utilized. Moreover, Sch. japonicus modulated the concentration of some volatile compounds when in mixed culture. In particular, ethyl acetate, that reached high levels at the end of alcoholic fermentation, showed a significant decrease after twenty-four months of bottle aging (p < 0.05), when the occurrence of hydrolysis/esterification reactions led to a significant increase of other acetate esters (p < 0.05). As a result, sensory analyses showed no significant differences for the ethyl acetate perception in mixed fermentation and control aged wines. Moreover, sequentially inoculated wines showed significantly higher sweetness compared to control wines, possibly due to the higher glycerol and polysaccharide content.