Red Wine Production Research Articles

Alzheimer's Disease Genetic Influences Impact the Associations between Diet and Resting-State Functional Connectivity: A Study from the UK Biobank.

Red wine and dairy products have been staples in human diets for a long period. However, the impact of red wine and dairy intake on brain network activity remains ambiguous and requires further investigation. This study investigated the associations between dairy and red wine consumption and seven neural networks' connectivity with functional magnetic resonance imaging (fMRI) data from a sub-cohort of the UK Biobank database. Linear mixed models were employed to regress dairy and red wine consumption against the intrinsic functional connectivity for each neural network. Interactions with Alzheimer's disease (AD) risk factors, including apolipoprotein E4 (APOE4) genotype, TOMM40 genotype, and family history of AD, were also assessed. More red wine consumption was associated with enhanced connectivity in the central executive function network and posterior default mode network. Greater milk intake was correlated with more left executive function network connectivity, while higher cheese consumption was linked to reduced posterior default mode network connectivity. For participants without a family history of Alzheimer's disease (AD), increased red wine consumption was positively correlated with enhanced left executive function network connectivity. In contrast, participants with a family history of AD displayed diminished network connectivity in relation to their red wine consumption. The association between cheese consumption and neural network connectivity was influenced by APOE4 status, TOMM40 status, and family history, exhibiting contrasting patterns across different subgroups. The findings of this study indicate that family history modifies the relationship between red wine consumption and network strength. The interaction effects between cheese intake and network connectivity may vary depending on the presence of different genetic factors.

Characteristics of red wines depending on the applied maceration method

Wine is an alcoholic beverage created as a product of alcoholic fermentation. It is a complex compound consisting of a large number of components (water, alcohols, acids, sugars, mineral substances, phenols, esters, glycerol, etc.). The chemical composition and quality of wine largely depend on the variety, wine type, production, and storage methods. Maceration is an essential part of the red wine production process. During maceration, numerous compounds are separated from the solid parts of the grape and berry and they are extracted into wine, and thanks to this process, red wine acquires most of its characteristics. It is considered that temperature and duration are the most important maceration factors that affect the quality of red wines. This paper aims to determine the influence of different maceration regimes on the quality of red wines of the Vranac and Merlot varieties. Vinification was carried out in 2021 in the Microbiology Laboratory of the Faculty of Technology in Banja Luka, where maceration regimes for 6 and 12 days were applied, at temperatures of 16 and 25°C. Wine quality analyses were done in the Laboratory for Ampelography and Winemaking at the Faculty of Agriculture in Banja Luka. Differences in wine quality were observed depending on the maceration regime. The highest alcohol content was observed after 6 days of maceration at 25°C, while prolonged maceration led to reduction in the alcohol content. The increased temperature had a positive effect on the total extract, as well as on the wine chromatic characteristics of both varieties. The wines of the Merlot variety had lower total acidity at longer maceration, while the wines of the Vranac variety had lower total acidity at shorter maceration. All analyzed wines had a satisfactorily low volatile acidity, as well as pH. The Merlot wines had the highest ash content after 12 days of maceration at 25°C, and the Vranac wines after 6 days of maceration at 25°C.

The impact of climate change on the sustainability of wine production and the structure of its consumption in Czechia

Vine-growing for the production of wine constitutes one of the major areas of agriculture of Czechia, and in recent years it has been qualitatively improved. The purpose of this study is to express the effects of climate change on the structure of wine production and consumption in the Czech Republic in connection with the growing local popularity of white wine consumption. The current consumer preferences of wine consumers in the Czech Republic (characterized by the growing popularity of white wines) are not in line with the effects of future climate change associated with the assumption of growing vine varieties suitable for the production of red wines. The methodology of the following study is based especially on the evaluation of statistical data about vine growing and wine production of Czechia and a research investigation about consumers’ preferences in the consumption of wines in Czechia. The effect of long-term climate change in the region are likely to lead to an increase in growing areas, especially in favour of vine varieties suitable for the production of red or rosé wines. The harvest of wine grapes, the hectare yield of grapes and the production of wine in Czechia do not show a significant development trend in the long-term time series of 2000–2019. Thus, in the future, the development of viticulture in Czechia will be influenced mainly by the location of the planted area of vineyards or the development of consumer habits and preferences.

The Effect of Seed Removal and Extraction Time on the Phenolic Profile of Plavac Mali Wine

The maceration process is one of the indispensable winemaking steps in red wine production that has a marked impact on phenolic compound extraction and can strongly influence the color and gustatory quality. Seed removal can have a substantial impact on the intensity of bitterness and astringency which are mainly influenced by the presence of flavanols. The main aim of this study was to investigate the influence of seed removal and extraction time on the phenolic composition, color parameters, and organoleptic properties of Plavac mali wines produced from the grapes from the Pelješac Peninsula. The achieved results showed that the control wines differ in terms of their highest content of total anthocyanins in both years and total flavonols in one year of investigation, while prolonged maceration without seeds decreases the concentration of phenolic acids as well as that of flavan-3-ols. A prolonged extraction time influenced the color intensity and tonality, moving it towards more yellow pigments. These changes could possibly be explained by the pronounced interaction between phenolic compounds and the formation of the new ones. Interestingly, seed removal probably diminished that change because the potential absorption of the anthocyanins by grape seeds and tannins were excluded. The highest quality was sensory defined in wines produced by prolonged maceration without seeds.

Aromatic ripeness may be the type of maturity that impacts red wine typicity the most. Part I: the aromas involved in aromatic ripeness

Harvesting grapes at the appropriate maturity is key to the production of high quality red wines. Viticulturists, oenologists and winemakers define several types of maturity: technological, phenolic and aromatic. Aromatic maturity is probably the most important for determining wine quality and typicity, including terroir expression. This article (part I) reviews the state-of-the-art of compounds underpinning aromatic maturity; the influence of terroir factors and management practices are addressed in a follow-up article (part II).

Optimization of A Procedure to Improve the Extraction Rate of Biologically Active Compounds in Red Grape Must Using High-Power Ultrasound

The primary focus in the production of quality red wine is the extraction of grape components, which can be achieved in a variety of ways. This work investigates the extraction yield of biologically active compounds from crushed Merlot grapes, as a result of ultrasound treatment applied before maceration, and optimizes the process parameters of a laboratory scale using response surface methodology (RSM) within a central composite design (CCD) model. The two factors whose response was studied were amplitude (A) % and treatment time (t), while the dependent variables were the total phenolic compounds (TPC), monomeric anthocyanins (MA), and antioxidant activity expressed as ferric reducing antioxidant power (FRAP) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity. The results showed that the application of high-power ultrasound treatment to crushed grapes for a few minutes increased both the extraction rate of bioactive compounds and the antioxidant activity by a maximum of 12 times for the TPC, 14 times for the MA, 3.6 times for the FRAP value, and 18.77% for the DPPH. The optimized solution had an amplitude of 90% and a treatment time of 4 min and 24 s. The validation experiments yielded errors between—8.70% and 3.14%, confirming the proposed model. Thus, the RSM model is recommended as a tool to optimize a procedure for enhancing both the extraction rate of the bioactive compounds from grapes and the antioxidant properties of grape must. Our results demonstrate the ultimate benefits of using ultrasonic treatment on crushed grapes at the beginning of the winemaking process, as a highly effective technique for improving the extraction of high-value bioactive chemicals, with significant application potential.

Combined Use of Schizosaccharomyces pombe and a Lachancea thermotolerans Strain with a High Malic Acid Consumption Ability for Wine Production

The development of new fermentative strategies exploiting the potential of different wine-related species is of great interest for new winemaking conditions and consumer preferences. One of the most promising non-conventional approaches to wine fermentation is the combined use of deacidifying and acidifying yeasts. Lachancea thermotolerans shows several other properties besides lactic acid production; among them, high malic acid consumption is of great interest in the production of red wines for avoiding undesirable refermentations once bottled. The combination of a L. thermotolerans strain that is able to consume malic acid with a Schizosaccharomyces pombe strain helps to ensure malic acid elimination during alcoholic fermentation while increasing the final acidity by lactic acid production. To properly assess the influence of this alternative strategy, we developed combined fermentations between specific strains of L. thermotolerans and S. pombe under sequential inoculation. Both species showed a great performance under the studied conditions, influencing not only the acidity but also the aromatic compound profiles of the resulting wines. The new proposed biotechnological strategy reduced the final concentrations of ethanol, malic acid and succinic acid, while it increased the concentrations of lactic acid and esters.

Development of a novel (poly)phenol-rich diet score and its association with urinary (poly)phenol metabolites.

Background: Estimating (poly)phenol intake is challenging due to inadequate dietary assessment tools and limited food content data. Currently, a priori diet scores to characterise (poly)phenol-rich diets are lacking. This study aimed to develop a novel (poly)phenol-rich diet score (PPS) and explore its relationship with circulating (poly)phenol metabolites. Methods: A total of 543 healthy free-living participants aged 18-80 years completed a food frequency questionnaire (FFQ) (EPIC-Norfolk) and provided 24 h urine samples. The PPS was developed based on the relative intake (quintiles) of 20 selected (poly)phenol-rich food items abundant in the UK diet, including tea, coffee, red wine, whole grains, chocolate and cocoa products, berries, apples and juice, pears, grapes, plums, citrus fruits and juice, potatoes and carrots, onions, peppers, garlic, green vegetables, pulses, soy and soy products, nuts, and olive oil. Foods included in the PPS were chosen based on their (poly)phenol content, main sources of (poly)phenols, and consumption frequencies in the UK population. Associations between the PPS and urinary phenolic metabolites were investigated using linear models adjusting energy intake and multiple testing (FDR adjusted p < 0.05). Result: The total PPS ranged from 25 to 88, with a mean score of 54. A total of 51 individual urinary metabolites were significantly associated with the PPS, including 39 phenolic acids, 5 flavonoids, 3 lignans, 2 resveratrol and 2 other (poly)phenol metabolites. The total (poly)phenol intake derived from FFQs also showed a positive association with PPS (stdBeta 0.32, 95% CI (0.24, 0.40), p < 0.01). Significant positive associations were observed in 24 of 27 classes and subclasses of estimated (poly)phenol intake and PPS, with stdBeta values ranging from 0.12 (0.04, 0.20) for theaflavins/thearubigins to 0.43 (0.34, 0.51) for flavonols (p < 0.01). Conclusion: High adherence to the PPS diet is associated with (poly)phenol intake and urinary biomarkers, indicating the utility of the PPS to characterise diets rich in (poly)phenols at a population level.

Physico-chemical Characterization and Polyphenolic Composition of Red Wines Produced from Autochthonous Grapes Varieties (Vitis vinifera) in Turkey

Aims: Local varieties of “Hönüsü” and “Horozkarası” red grapes have been evaluated for the production of red wine and characterized33 for their chemical and sensory characteristics.&#x0D; Study Design: This research was initiated by the Food microbiology researcher and Applications Unit of Fermentation Laboratory.&#x0D; Place and Duration of Study: Laboratory of Fermentation of the Food Engineering Department in Gaziantep University, October 2019 to May 2021.&#x0D; Methodology: All wines were produced by a standard procedure of vinification. Three types of red wines were produced from combinations of red grapes. Ten phenolics were quantitatively detected in the red wines during processing. Brix, alcohol, pH and free SO2 contents were also detected.&#x0D; Results: The results showed that the type of technology affects significantly (p&lt;0.05) the level of phenolic compounds formed during processing. Horozkarası” red grape contributed to the highest amount of phenolic compounds in red wines. Gaziantep wine provides valuable information about the production of red wine from Gaziantep red grapes.&#x0D; Conclusion: The phenolic compounds of red wines were significantly (p&lt;0.05) higher than that of musts. Many of the remarkable features of the phenolic profiles and Brix of grape varieties could help us to characterize Gaziantep wines. The mixture of must from “Hönüsü” and “Horozkarası” red grapes with 7:3 ratio contributes suitable sugar and phenolic compounds for red wine. The results from this study provide valuable information about the red wine produced from the ancient grape varieties of the Southeast region.

Preliminary study of novel autochthonous starter culture for red wine production with reduced biogenic amine content

AbstractMost Chilean red wine is produced by spontaneous malolactic fermentation (MLF), which generates prolonged fermentations resulting in uncertain results, increase production cost, and lead to biogenic amine (BA) formation. The objective of this work was to carry out a preliminary study of an autochthonous MLF starter culture to perform shorter and controlled MLF to elaborated red wines with low BA content. The autochthonous Oenococcus oeni strain (OoB6) isolated from spontaneous MLF was assayed in bioreactors using filtered and unfiltered wines. OoB6 strain efficiently carried out MLF samples showing a similar performance to commercial starter culture. Both accomplished malic acid concentrations (&lt;0.12 g/L) significantly lower (p &lt; .05) than the initial content (1.21 ± 0.11 g/L). OoB6 strain produced a 50% reduction in MLF time and showed very low BA formation (ca. 5 mg/L) without detecting the presence toxicological important BA histamine and tyramine.Novelty impact statement To the best of our knowledge, this work report for the first time a preliminary study of potential autochthonous MLF starter culture to elaborate Chilean red wines. Autochthonous MLF starter culture produced a 50% reduction in MLF time compared with traditional spontaneous MLF. Autochthonous MLF starter culture showed very low BA formation (ca. 5 mg/L) without detecting the presence toxicological important BA histamine and tyramine.

Prediction of Nitrogen Dosage in 'Alicante Bouschet' Vineyards with Machine Learning Models.

Vineyard soils normally do not provide the amount of nitrogen (N) necessary for red wine production. Traditionally, the N concentration in leaves guides the N fertilization of vineyards to reach high grape yields and chemical composition under the ceteris paribus assumption. Moreover, the carryover effects of nutrients and carbohydrates stored by perennials such as grapevines are neglected. Where a well-documented database is assembled, machine learning (ML) methods can account for key site-specific features and carryover effects, impacting the performance of grapevines. The aim of this study was to predict, using ML tools, N management from local features to reach high berry yield and quality in ‘Alicante Bouschet’ vineyards. The 5-year (2015–2019) fertilizer trial comprised six N doses (0–20–40–60–80–100 kg N ha−1) and three regimes of irrigation. Model features included N dosage, climatic indices, foliar N application, and stem diameter of the preceding season, all of which were indices of the carryover effects. Accuracy of ML models was the highest with a yield cutoff of 14 t ha−1 and a total anthocyanin content (TAC) of 3900 mg L−1. Regression models were more accurate for total soluble solids (TSS), total titratable acidity (TTA), pH, TAC, and total phenolic content (TPC) in the marketable grape yield. The tissue N ranges differed between high marketable yield and TAC, indicating a trade-off about 24 g N kg−1 in the diagnostic leaf. The N dosage predicted varied from 0 to 40 kg N ha−1 depending on target variable, this was calculated from local features and carryover effects but excluded climatic indices. The dataset can increase in size and diversity with the collaboration of growers, which can help to cross over the numerous combinations of features found in vineyards. This research contributes to the rational use of N fertilizers, but with the guarantee that obtaining high productivity must be with adequate composition.

Selecting south European wine based on carbon footprint

The largest wine producers globally are located in Southern Europe and climate is a major factor in wine production. The European Union aims to complement the consumer’s choice for wine with information about environmental sustainability. The carbon footprint is a worldwide-standardized indicator that both wine producers and consumers perceive as the most important environmental indicator. So far, environmental life cycle assessment studies show variability in the system boundaries design and functional unit selection, and review papers do not include life cycle inventory data, and consider vineyards in various locations worldwide. This study aimed to investigate what are the key factors affecting the carbon footprint of red and white wine production in South European countries with the same climatic conditions, and benchmark both wine types. The results showed that the carbon footprints of white and red wines are comparable. The average carbon footprints were 1.02, 1.25, and 1.62 CO 2 eq. bottle of wine −1 for organic red wine, conventional red wine, and conventional white wine, respectively. The viticulture, winemaking, and packaging stages affect greatly the carbon footprint. Diesel consumption at the viticulture stage, electricity consumption at the viticulture and winemaking stages, and glass production at the packaging stage are the largest contributors to the carbon footprint. Wine consumption stage was omitted from most studies, even though it can increase the carbon footprint by 5%. Our results suggest that consumers should choose (conventional or organic) red wine that is produced locally. • This review investigates the carbon footprint of red and white wines. • The review considers the LC inventories of reviewed studies. • Organic red wine shows the lowest carbon footprint. • Red wine has a lower carbon footprint than white wine.

Determination of trace levels of organic fining agents in wines: Latest and relevant findings.

The production of red wine plays a key role in the local and international economies of several nations. During the winemaking process, to clarify the final product, before bottling, and to remove undesired substances (proteins, phenols, and tannins), fining agents are commonly added to wines. These substances have different origins (animal and vegetable proteins or mineral compounds), and they show a potential risk for the health of allergic subjects. For these reasons, the residues of fining agents, constituted by exogenous proteins based on gluten, egg, and milk proteins, should not be present in the final product and their trace residues should be quantified with accuracy. In the last decade, several analytical approaches have been developed for their quantitative determination using different sample treatment protocols and analytical techniques. These methods are based on liquid chromatography coupled with mass spectrometry or enzyme-linked immunosorbent assays (ELISAs). Recently, biosensors have been proposed as a potential alternative to immunoassay approaches, allowing rapid, cheap, and simple multi-residue detection. This short review aimed to report the most recent and relevant findings in the field.

Climate change projections for UK viticulture to 2040: a focus on improving suitability for Pinot Noir

Between 1981–2000 and 1999–2018, growing season average temperatures (GST) in the main UK viticulture regions have warmed ~1.0 °C and are now more reliably &gt;14.0 °C GST. This warming has underpinned the rapid expansion of the UK viticulture sector and its current focus on growing grape varieties for sparkling wine. Near-term (2021–2040) climate change may condition opportunities for further variety and/or wine style changes. Using the latest high-resolution (5 km) ensemble (×12) of downscaled climate change models for the UK (UK Climate Projections; UKCP18) under Representative Concentration Pathway (RCP) 8.5, we calculate near-term trends and variability in bioclimatic indices (BCIs). We simulate the projected repetition of the UK’s highest yielding season—2018—and use an analogue approach to model the 1999–2018 mean growing season temperatures from Pinot Noir producing areas of Champagne (France), Burgundy (France) and Baden (Germany) over the UK during 2021–2040. We also project, across the UK for the 2021–2040 period, BCI values of recent high-quality vintage years from Champagne and Burgundy. GST are projected to increase from a 1999–2018 spatial range of 13.0 (minimum threshold) –15.7 °C to a future (2021–2040) range of 13.0–17.0 °C, and Growing Degree Days (GDD) from 850 (minimum threshold) –1267 to 850–1515. Growing season precipitation (GSP) is projected to decline in some UK viticulture areas but is not modelled as a limiting viticulture factor. High inter-annual weather variability is simulated to remain a feature of the UK viticulture climate and early season frost risk is likely to occur earlier. Large areas of the UK are projected to have &gt;50 % of years within the bioclimatic ranges experienced during the 2018 growing season, indicating potential higher yields in the future. The 1999–2018 mean Champagne, Burgundy and Baden GST and GDD are projected for much of England and some areas in the far south and south-east of Wales during 2021–2040, with significant areas projected to have &gt;25 % of years within the BCI ranges of top Champagne vintages. These results indicate greater potential for Pinot Noir for sparkling wines and shifting suitability to still red wine production. Accounting for changes in variety suitability and wine styles will be essential to maximise opportunities and build resilience within this rapidly expanding wine region.

Biochemical composition and antioxidant activity of the mannoprotein preparation obtained yeast biomass from wine industry waste

In this study, the procedure of obtaining new biologically active mannoprotein preparation based on the yeast biomass from the residues of the wine industry, namely the production of Merlot dry red wine is presented. The process for obtaining of the preparation includes lysis of the yeast cell wall with sodium phosphate buffer, extraction of anthocyanins by treatment with 50% alcohol solution, hydrolysis with 1N NaOH, sedimentation of mannoproteins with ethyl alcohol, centrifugation and dissolution of purified sediment in distilled water, standardization of the preparation obtained up to a concentration of 10 mg/ml. As a result, it has been established that the mannoprotein preparation possesses a valuable biochemical composition characterized by a high content of proteins, carbohydrates, anthocyanins, and a wide range of minerals, macro, microelements, and does not practically contain heavy metals. Due to its biochemical composition, the preparation, also, possessed antioxidant activities and high catalase and superoxide dismutase activity. In conclusion, we can mention that the varied biochemical composition, antioxidant, and enzymatic activity highlight the high biological value of the mannoprotein preparation and the enormous potential for implementation in various fields, especially in animal husbandry and viticulture, food and cosmetic industry.

Aromatic maturity is a cornerstone of terroir expression in red wine

Harvesting grapes at adequate maturity is key to the production of high-quality red wines. Viticulturists, enologists, and wine makers define several types of maturity, including physiological maturity, technological maturity, phenolic maturity, and aromatic maturity. Physiological maturity is a biological concept. Technological maturity and phenolic maturity are relatively well documented in the scientific literature, being linked to quantifiable compounds in grape must. Articles on aromatic maturity are scarcer. This is surprising, because aromatic maturity is, probably, the most important of the four in determining wine quality and typicity, including terroir expression, i.e. the identifiable taste of wine in relation to its origin. Optimal terroir expression can be obtained when technological, phenolic, and aromatic maturity are reached at the same time, or within a short time frame. This is more likely to occur when the ripening takes place under mild temperatures, neither too cool, nor too hot.Aromatic expression in wine can be driven, in order from low to high maturity, by green, herbal, spicy, floral, fresh fruit, ripe fruit, jammy fruit, dried fruit, candied, or cooked fruit aromas. Green and cooked fruit aromas are not desirable in red wines, while the levels of other aromatic nuances contribute to the typicity of the wine in relation to its place of origin. Wines produced in cool climates, or on cool soils in temperate climates, are likely to express herbal or fresh fruit aromas, while wines produced under warm climates, or on warm soils in temperate climates, may express ripe fruit, jammy fruit, or candied fruit aromas.This article reviews the state of the art of compounds underpinning the aromas of wines obtained from grapes harvested at different stages of maturity. Advances in the understanding of how aromatic maturity shapes terroir expression and how it can be manipulated by variety choices and management practices, under current and future climatic conditions, are shown. Early ripening varieties perform better in cool climates and late ripening varieties in warm climates. Additionally, maturity can be advanced or delayed by different canopy management practices or training systems. Timing of harvest also impacts aromatic expression of the produced wine. Gaps in the literature are highlighted to guide future directions of research.

Continuous malolactic fermentation of red wine in a reactor using silica-alginate encapsulated Oenococcus oeni

Malolactic fermentation (MLF) is a challenging and time-consuming step in the winemaking process. The effects of climate change are making the intrinsic conditions in red wine more challenging for the growth of lactic acid bacteria through interfering with a prompt and effective MLF. However, this is a necessary process in red wine production that contributes to high quality of wine demanded by consumers. Previous studies in our group reported a highly efficient MLF of red wine by using encapsulated Oenococcus oeni. Here, we designed a bench-scale packed-bed reactor using encapsulated bacteria to facilitate and speed up this process. The time to complete MLF was reduced as the concentration of biocapsules increased. The system exhibited operational stability and efficiency in sequential batches of wine recirculated through the column. Furthermore, an efficient continuous MLF was achieved using the packed-bed reactor. In general, a slight reduction in the concentration of some volatile organic compounds (VOCs) in the wines from the continuous system was observed as compared to those from the recirculated system.

Dietary Flavonoids as Modulators of Lipid Metabolism in Poultry

Flavonoids, naturally-occurring compounds with multiple phenolic structures, are the most widely distributed phytochemicals in the plant kingdom, and are mainly found in vegetables, fruits, grains, roots, herbs, and tea and red wine products. Flavonoids have health-promoting effects and are indispensable compounds in nutritional and pharmaceutical (i.e., nutraceutical) applications. Among the demonstrated bioactive effects of flavonoids are anti-oxidant, anti-inflammatory, and anti-microbial in a range of research models. Through dietary formulation strategies, numerous flavonoids provide the ability to support bird health while improving the nutritional quality of poultry meat and eggs by changing the profile of fatty acids and reducing cholesterol content. A number of such compounds have been shown to inhibit adipogenesis, and promote lipolysis and apoptosis in adipose tissue cells, and thereby have the potential to affect fat accretion in poultry at various ages and stages of production. Antioxidant and anti-inflammatory properties contribute to animal health by preventing free radical damage in tissues and ameliorating inflammation in adipose tissue, which are concerns in broiler breeders and laying hens. In this review, we summarize the progress in understanding the effects of dietary flavonoids on lipid metabolism and fat deposition in poultry, and discuss the associated physiological mechanisms.

Technological assessment of native grapes varieties for winemaking in the conditions of Southern Dagestan

B The article says about the role of native varieties of Dagestan in improving the assortment of grapes. It provides the information on the indigenous grape varieties in the varietal composition of the vineyards of the region. A detailed technological assessment of four Dagestan native wine grape varieties of Scarlet Tersky, Asyl Kara, Gimra and Makhbor tsibil in the conditions of Southern Dagestan is given. The data of yield, mechanical composition of bunches, chemical composition of berries, chemical composition and tasting evaluation of red table wines from native grape varieties are given. Analysis of the chemical composition and organoleptic evaluation have shown that the wines from the indigenous varieties Asyl Kara, Gimra and Mahbor tsibil are at the level or superior in quality to the sample from the control variety Saperavi. Based on the research results, it is recommended to expand the area of grapes of the indigenous varieties Asyl Kara, Gimra and Makhbor tsibil in Southern Dagestan and the production of high-quality red table wines from them.

Investigating the Effect of Yeasts and their Derivatives on the Qualitative Indices of Red Wine

The study on the influence of yeast and yeast derivative autolyzes on the wine qualitative and quantitative characteristics has been conducted upon the first article of the series. Red grapes contain more than 1500 components, which are forming the taste and aroma of red wines, as well as the biological value of the product. One of the main technological operations in the production of red wines, which is related to the creation of favorable conditions for extracting phenolic and coloring compounds from the solid parts of the grape berry that are responsible for the color, taste, and aroma preserving them at the different stages of the wine formation and maturation, has been researched and analyzed.