Tokaj Wine Research Articles

Establishing a pattern of change in the quality indicators of Tokaj-type wine materials prepared by different variants

The object of this study is Tokaj-type wine materials made from white and red grape varieties grown in the foothills of the Goy-Gol region and the flat zone of the Samukh region in the Azerbaijan Republic. An important condition for the production of Tokaj wine is the high sugar content in the raw materials. Therefore, fully ripe and slightly withered grape varieties were used to prepare the wine materials. The quality indicators of wine materials prepared in three options were studied. Option 1 – preparation of Tokaj wine material by adding must with pulp from ripe grapes to alcohol; Option 2 – preparation of Tokaj wine material by adding must with pulp from grapes withered on the vine for 10–12 days to alcohol; Option 3 – preparation of Tokaj wine material by adding must with pulp from grapes withered on the vine for 4–5 days to alcohol. The most appropriate options were the first and second, according to which Tokaj wine material is produced by adding must with pulp from grapes ripened and dried on the vine for 4–5 days to alcohol. The content of sugar, volatile acids, titratable acidity, phenolic compounds, methyl alcohol, and the volume percentage of alcohol added to the must were studied in the prepared wine materials. For the preparation of wine material, it is advisable to use the white Rkatsiteli grape variety and the red Cabernet Sauvignon variety grown in the flat zone of the Samukh district. This is due to the fact that in the flat zone, grapes accumulate more sugar, and the volume percentage of alcohol added to the must is less, which is also economically advantageous. During the study, using mathematical and statistical methods, the most appropriate option was determined for the organoleptic indicators of Tokaj wines made from the Rkatsiteli grape variety, which was rated 9.8 points

Volcanic tuff as a World Heritage Georesource, a Case Study of Tokaj Wine Region UNESCO Cultural Landscape

Volcanic tephra and pyroclastic rocks are common georesources worldwide. Volcanic eruptions produce these materials, and the freshly deposited volcaniclastic sediments undergo variable diagenesis and possible hydrothermal alteration. The rhyolitic pyroclastic rocks of the Carpathian Basin were formed as a result of major silicic volcanism during the Miocene and are exposed in several volcanic regions. The use of these stones depends on their physical properties, such as hardness, colour, and transportability, especially in masonry and ornamental design. The study site, the Tokaj Wine Region (TWR) Historic Cultural Landscape is a UNESCO site located in NE Hungary, which was inscribed on the World Heritage List in 2002. The silicic pyroclastic rocks, here we also referred to them as rhyolite tuffs, are significant geological resources in the UNESCO cultural heritage designation. The pyroclastic formations cover an area of about 100 km2 and were deposited by three major explosive eruptions (13.1–11.5 Ma). The local varieties are defined by primary volcanological features and secondary (diagenetic, hydrothermal) effects. The stone was extracted from more than 40 open pit quarries dating from the Middle Ages. The wine cellars and dry-built terrace walls are important cultural features of the volcanic tuff use. The geoconservation value of the rhyolite tuff is well illustrated by the exposed special geological features, which represent important sites of volcanic formations. However, only one site has been declared a nature conservation area. Several historic quarries are currently abandoned, and there are many problems due to the lack of their restoration. The most common problems are the instability of quarry walls, illegal dumping, pollution, and dense vegetation covering the geological values. The volcanic tuff has a great potential as a georesource (quarries, cellars, and terrace walls) adding value to World Heritage Site, but special efforts are needed to demonstrate its potential for geoconservation, geotourism, and geo-education.

Impact of climate change on the (poly)phenol composition of botrytization in the Tokaj wine region

Tokaj wine region is famous for its aszú wines, which are made of noble rotted raw materials. There is also a continuous change in the life activity of Botrytis cinerea as a result of climate change, which not only alters the rate of acidification but also its characteristic biochemical processes. Increasing sugar content is associated with a fructose excess, an increase in succinic acid, fumaric acid, citric acid, a change in the composition of phenolic compounds and an increase in phenolic acid content. This study examines the polyphenol content measured in the last 4 vintages and presents the typical phenolic acid composition.

Development of a qPCR method for classification of botrytized grape berries originated from Tokaj wine region

One of the best-known Hungarian products on world wine market is Aszú, which belongs to the family of Tokaj wine specialties and is made from aszú berries. An important condition for the formation of aszú berries is the noble rot of technologically mature grapes, which is caused by Botrytis cinerea. At the same time botrytized sweet wines are produced not only in Hungary, but in many locations of wine-producing areas of Europe as well as in certain wine growing regions of other continents. The determination of botrytization is mostly based on sensory evaluations, which is a highly subjective procedure and largely depends on the training and experience of the evaluator. Currently, the classification of aszú berries (class I and class II) is based only on visual inspection and determination of sugar content.Based on these facts the primary goal of our work was to develop a qPCR assay capable for objective rating and classification of aszú berries.The developed qPCR is highly specific and sensitive as can clearly distinguish between B. cinerea and other filamentous fungi and yeast species occur on grapes. Moreover, it is suitable for categorizing berries colonized by B. cinerea to varying degrees. Thus, the developed qPCR method can be a useful technique for classification of the grape berries into four quality groups: healthy, semi-shrivelled, Aszú Class II and Aszú Class I.

A digital image smartphone-based approach to Slovak Tokaj wine authentication chemometric assisted

The authentication of Slovak wines in comparison to other similar wines from various geographical regions, namely Hungary, France, Austria, and Ukraine, was conducted using the OC-PLS, DD-SIMCA, and PLS-DM models, all of them operating in rigorous way. The study involved 63 samples, of which 41 originated from Slovakia, covering diverse wine types such as varietal wines, cuvée selections (different “putňový”), and essence. To capture digital images under controlled conditions, a custom-made cardboard box with white inner surfaces was devised and equipped with a smartphone. During the training phase, sensitivities of 96%, 100%, and 96% were attained for OC-PLS, DD-SIMCA, and PLS-DM, respectively. In the subsequent stages of validation and testing for DD-SIMCA and PLS-DM, the proposed methods displayed optimal efficiency, achieving both sensitivity and specificity rates of 100%. However, such results were not achieved in the case of OC-PLS, which exhibited efficiency levels of 90% in validation and 80% in testing.

Improvement of technology for producing wine material for Tokaj wine

The object of this study is the production technology of Tokaj-type wine materials. The material used was white and red grape varieties, withered by twisting on the vine for 4–5 days. Wine materials were prepared from these grape varieties using new technology, i.e., by adding the wort to the alcohol along with the pulp. The technology for the production of environmentally friendly Tokaj-type sweet dessert wines using technical grape varieties cultivated in the foothills of the Goy-Gol and flat zone of the Samukh region has been improved. Providing the population with environmentally friendly food products, as well as wines, is one of the most important tasks of our time. Poor quality food creates conditions for the development of various diseases. For this purpose, a technological scheme for the production of Tokaj-type wine materials has been devised. The quality indicators of Tokaj wine material prepared by fermenting in alcohol must from grapes withered by twisting on the vine for 4–5 days with pulp for 3–4 days were studied. The rates of alcohol loss were calculated based on the contraction coefficient (0.08 %) during co-fermentation with wort. For wine materials prepared from grape varieties grown under the conditions of the Samukh region, alcohol consumption is reduced. This is due to the high sugar content in the wine material. In the prepared wine material, the amount of alcohol and sugar corresponded to the norm – the alcohol content reached 14–15 % and residual sugar 16 %. As a result of the tasting, wine material prepared from the Rkatsiteli grape variety in the Samukh region was rated 9.5 points, and wine material prepared from the red Madras grape variety 9.3 points. The results make it possible to regulate the desired quality of wine material and use it in the production of Tokaj wine

Administrative Law without Borders

An international conference, entitled “Administrative Law without Borders” was organised by the Faculty of Law, University of Košice in the municipality Veľká Třňa, which is situated in the very heart of the Slovak area of the Tokaj wine region. The conference was organised under the research project “Extraterritorial effects of foreign administrative decisions in the European Union”, which has been supported by the Scientific Agency VEGA. The Košice-based research team, under the leadership of Associate Professor Radomír Jakab, has been dealing with various problems arising from mutual recognition of foreign administrative decisions for several years, and the conference, as organised on 19th and 20th October 2023 in the Tokaj Wine Region, represents one of the major academic meetings organised under the umbrella of this academic endeavour.

Exploring the eighteenth-century concept of soil as reflected in Sámuel Domby's De vino Tokaiensi

AbstractThe treatise De vino Tokaiensi (On Tokaj Wine) written by Sámuel Domby of Gálfalva (1729–1807), is a valuable source on Hungarian history of culture and science which has become widely accessible thanks to its facsimile edition. This medical doctoral dissertation published in 1758 in Utrecht presents a study of the medicinal effects of Tokaj wine, mirroring the norms of philosophical-scientific literature in eighteenth century Hungary. It is unequivocally an exceptional document of the intellectual heritage of the educated classes in the early modern age regarding growth habitat, viticulture and winemaking, with specific reference to Tokaj-Hegyalja, a wine region and cultural landscape of historic importance in Northeast Hungary. The present paper aims at identifying the perceptions detailed in the candidate's argument in pedological terms.

The origin of the particular aroma of noble rot wines: various fungi contribute to the development of the aroma profile of botrytised grape berries

During noble rot (NR), B. cinerea, together with other filamentous fungi and yeasts, play a role in developing the unique aromatic profile of botrytised wines. To gain more insight into the latter, we generated metatranscriptomic data representing the four NR stages (I-IV) from the Tokaj wine region of Hungary over three months. Since previous research has indicated that the most prevalent filamentous fungi and yeast include Alternaria alternata, Botrytis cinerea, Epicoccum nigrum, Aureobasidium pullulans and Rhodotorula graminis, RNAseq reads were aligned to the latter species. A weighted gene co-expression network analysis (WGCNA) followed by a non-metric multidimensional scaling (NMDS), eigengene ANOVA and enrichment analyses were performed. Amongst the ten generated gene module clusters, enriched pathways involved in synthesising aromatic compounds such as amino acid-, carbohydrate- and lipid metabolism co-jointly expressed by all filamentous fungi and yeast were identified within the turquoise module. Furthermore, it was found that the enzymes involved in the synthesis of aromatic compounds are expressed and up-regulated during the later stages (III-IV) of the NR process. This study has indicated that the unique aromatic profile of botrytised wines is due to the contributions of filamentous fungi and yeasts belonging to the NR grape microbiome, with the main aromatic contributions occurring during the later NR stages.

Starmerella lactis-condensi, a yeast that has adapted to the conditions in the oenological environment

The yeast Starmerella (Candida) lactis-condensi is considered a food contaminant microorganism. The aim of our research was to determine why St. lactis-condensi could become the dominant species of Essences, the top sweet wine speciality of Tokaj wine region in Hungary. We investigated the physiological properties of these yeasts based on parameters that may influence their ability to selectively proliferate and persist during maturation in wines with very high sugar content. These include glucose and fructose, alcohol, and sulphur tolerance. Our studies have shown that St. lactis-condensi is a fructophilic yeast that is able to adapt quickly to very high sugar concentrations (up to 500 g/L) in the Essences. The high glucose concentration inhibits its growth, as well as that of the St. bacillaris (Candida zemplinina) strains tested. The type and amount of sugars in the Essences, together with the sulphur and alcohol content, influence the composition of the dominant yeast biota. Analysis of (GTG)5 microsatellite in the nuclear genome and mtDNA-RFLP studies demonstrate that a diverse population of St. lactis-condensi occurs in the Tokaj wine region, in the Essences. This yeast species is characterised by both physiological and genetic biodiversity. GC–MS analysis of Essences colonised exclusively with these yeasts showed no deterioration in quality.

Effect of Botrytis cinerea Activity on Glycol Composition and Concentration in Wines

The content of 2,3-butanediol ((R,R) and meso isomers) and 1,2-propanediol in grape berries and “liquid samples” (all non-berry extracts) from the Tokaj wine region of Hungary was investigated. Our aim was to find out how the activity of Botrytis cinerea influences the concentrations of these compounds compared with healthy grapes. Based on the measured concentrations, we can make a distinction between healthy berries and noble, rotted, so-called aszú berries. We also investigated if there is a difference between finished aszú wines and liquids intended for aszú production. We wanted to investigate the amount and distribution of the stereoisomers of 2,3-butanediol and their proportions. The results of the HS-SPME-GC-FID analysis of the samples showed significant differences in the 2,3-butanediol content between healthy and botrytised, aszú berries and between liquid samples for aszú production and aszú wines. In the berry samples, meso-2,3-butanediol could not be detected, whereas in the liquid samples, we found good amounts of this isomer. This may be due to the fact that the appearance of the meso form of 2,3-butanediol is a consequence of alcoholic fermentation. Significant differences were found between wines from healthy grapes and wines from botrytised grapes in terms of the levo-2,3-butanediol content, so that from an analytical point of view, a difference can be made between wines from healthy and botrytised grapes. No significant differences were found between berry and liquid samples in terms of 1,2-propanediol concentrations during our tests.

Radiocarbon dating of microliter sized Hungarian Tokaj wine samples

Radiocarbon-based age determination of wine samples has a great tradition worldwide, but most of the applied techniques, such as liquid scintillation counting and gas proportional counting analyses, have had large sample size requirements. However, accelerator mass spectrometry (AMS) based radiocarbon dating methods require much lower amount of carbon. Up to now, only a few available studies applied the AMS method to the dating of wine. We tested a preparation and measurement protocol for wine radiocarbon dating, not only for the ethanol fraction but for the distillation residue and submilliliter level preparation method of the wine sample without separation was also applied, using capillaries of the twenty wine samples from the Hungarian Tokaj wine region. The reliability of our method was verified by a comparison of wine time series with the Northern Hemisphere Zone 1 atmospheric 14C data as a calibration curve. The measured 14C values of the two different fractions, the ethanol and distillation residue, and the milliliter-sized non-separated samples also were in good agreement with each other, which shows both fractions could be used for radiocarbon dating of wine samples. Small sample size (~10 μL) wine radiocarbon dating does not destroy a significant part of a bottle of wine.

HPLC Analysis of Polyphenols Derived from Hungarian Aszú from Tokaj Wine Region and Its Effect on Inflammation in an In Vitro Model System of Endothelial Cells.

Many studies have been published in recent years regarding the fact that moderate wine consumption, as a part of a balanced diet can have a beneficial effect on human health. The biologically active components of wine continue to be the subject of intense research today. In this study, the bioactive molecules of Hungarian aszú from the Tokaj wine region were analyzed using high-performance liquid chromatography (HPLC) and investigated in an in vitro model system of endothelial cells induced by bacterial-derived lipopolysaccharide. The HPLC measurements were performed on a reversed phased column with gradient elution. The non-cytotoxic concentration of the active substance was determined based on 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyltetrazolium bromide (MTT)-, apoptosis, and necrosis assays. The antioxidant effect of the extract was determined by evaluating its ability to eliminate ROS. The expressions of the interleukin-(IL)1α, IL1-β, IL-6, and IL-8 pro-inflammatory cytokines and nitric oxide synthase (eNOS) at the mRNA level were evaluated using a quantitative polymerase chain reaction (qPCR). We found that the lipopolysaccharides (LPS)-induced increases in the expressions of the investigated cytokines were significantly suppressed by Hungarian aszú extract, excluding IL-6. In our experimental setup, our treatment had a positive effect on the eNOS expression, which was impaired as a result of the inflammatory manipulation. In our experimental model, the Hungarian aszú extract decreased the LPS-induced increases in the expression of the investigated cytokines and eNOS at the mRNA level, which presumably had a positive effect on the endothelial dysfunction caused by inflammation due to its strong antioxidant and anti-inflammatory effects. Collectively, this research contributes to a more thorough understanding of the bioactive molecules of aszú from the Tokaj wine region.

Enhanced multi-stir bar sorptive extraction for wine analysis: Alteration in headspace mode

Multi-stir bar sorptive extraction (multi-SBSE) represents a viable alternative for recent trends in sample preparation based on a combination of extraction techniques. In this case, increased amount of sorbent and its extended polarity range could advance quality of experimental data obtained in foodomics or metabolomics investigations. With this in mind, it was developed multi-SBSE procedure suitable for authentication of botrytized wine produced in different countries of Tokaj wine region. A design of headspace mode of multi-SBSE was modified to provide additional agitation of a stir bar. An expanded profile of wine samples was obtained with the application of EG-Silicone and PDMS coated stir bars in headspace and direction immersion mode, respectively. Multivariate optimization based on central composite design was selected to determine the influence of various experimental parameters, including extraction temperature enhancing headspace extraction. In our case, proper description of the optimization results required application of a third-order polynomial model, which highlighted dominant influence of salt addition for extraction in both modes. Due to a large number of extracted compounds, comprehensive two-dimensional gas chromatography (GC × GC) was used for assessment of wine samples. Such approach allows reveleaing the presence of sulphur containing compounds, diols, ketone derivatives and methoxybenzenes linking a specific geographical origin. At the same time, the results obtained for compounds common for all the samples were processed with principal component analysis (PCA). Considerable progress for discrimination of the botrytized wines was mainly achieved with combined data from EG-Silicone and PDMS extraction.

Optimization of enantiomer separation in flow-modulated comprehensive two-dimensional gas chromatography by response surface methodology coupled to artificial neural networks: Wine analysis case study

In spite of extensive applications of flow modulated comprehensive two-dimensional gas chromatography (FM-GG × GC) in different research areas, its application in the field of chiral separation is very limited. From a practical point of view, the establishment of experimental parameters for enantiomer separations is possibly more demanding in this case. Since the carrier gas flows in both dimensions, it affects not only the separation parameters, but also the fill/flush volumes of the modulator and its working efficiency. In this context, a multivariate design of experiment was applied to find the optimum experimental parameters of a reversed fill/flush (RFF) modulator for enantiomer separation of organic compounds present in botrytized wine samples. The results were described both with response surface methodology and artificial neural networks (ANN). The enantiomeric composition of chiral compounds present in the botrytized wines was used to identify their geographical origin, by principal component analysis (PCA). In addition, the developed one-class partial least squares (OC-PLS) model enabled recognition of the wine samples from the Tokaj wine region with 93% effectiveness in the presence of other samples.

Botrytis cinerea expression profile and metabolism differs between noble and grey rot of grapes

Botrytis cinerea, the pathogen causing grey rot (GR) with important economic losses in fruit crops, can also cause noble rot (NR) of grape berries under certain environmental conditions, leading to metabolic and physical changes necessary for producing highly regarded botrytized wines. The functional genes involved in biochemical processes in these harmful vs. beneficial berry rot types are still scarcely understood. We generated and analyzed transcriptomic data from healthy (H), NR and GR grape berries collected in the Tokaj wine region in Hungary. Our study shows that B. cinerea is most active in NR, followed by GR and H berries. In addition, expression profiles differed qualitatively between NR and GR, and to a smaller extent between months. Several functional genes expressed during NR were linked to well-known physico-chemical changes in botrytized grape berries, including berry skin degradation and the formation of metabolites favorable for botrytized wine production. In addition, we found that B. cinerea appeared to express genes involved in the biosynthesis of antimicrobials during NR, but not in GR, which likely contributes to the dominance of this fungus during NR.

Metatranscriptomic Analyses Reveal the Functional Role of Botrytis cinerea in Biochemical and Textural Changes during Noble Rot of Grapevines.

Botrytis cinerea, can lead to the formation of noble rot (NR) of grape berries under certain environmental conditions, resulting in favored metabolic and physical changes necessary for producing highly regarded botrytized wines. The functional genes involved in the textural and biochemical processes are still poorly characterized. We generated and analyzed metatranscriptomic data from healthy (H) berries and from berries representing the four stages of NR from the Tokaj wine region in Hungary over three months. A weighted gene co-expression network analysis (WGCNA) was conducted to link B. cinerea functional genes to grape berry physical parameters berry hardness (BH), berry skin break force (F_sk), berry skin elasticity (E_sk), and the skin break energy (W_sk). Clustered modules showed that genes involved in carbohydrate and protein metabolism were significantly enriched in NR, highlighting their importance in the grape berry structural integrity. Carbohydrate active enzymes were particularly up-regulated at the onset of NR (during the transition from phase I to II) suggesting that the major structural changes occur early in the NR process. In addition, we identified genes expressed throughout the NR process belonging to enriched pathways that allow B. cinerea to dominate and proliferate during this state, including sulphate metabolizing genes and genes involved in the synthesis of antimicrobials.

The Content of Selected Bioactive Compounds in Wines Produced from Dehydrated Grapes of the Hybrid Variety 'Hibernal' as a Factor Determining the Method of Producing Straw Wines.

Sweet wines are appreciated worldwide; many are produced by fermenting the must of dehydrated (semi-dried) grapes, using methods that vary from region to region. The aim of this study was to evaluate the basic chemical and oenological characteristics of wines obtained by three technologies of production. The wines were made from a hybrid cultivar ‘Hibernal’, grown under cool climate conditions. ‘Hibernal’ is a hybrid variety. This ‘Hibernal’ variety is widely cultivated in central and eastern Europe, where it is of great economic importance. Wines produced from this variety are popular in local markets. In comparison with the production of varieties belonging to Vitis vinifera, a very small percentage of the ‘Hibernal’ variety is cultivated. The methods used in the experiment for the production of wines were: classical method in the Italian passito style, modification of the passito style with a seven-day maceration of grapes, and a method of production in the Tokaj wine style at five Puttonyos. Basic chemical parameters, acid profile, total phenolic content, antioxidant and antiradical capacities, and quantitative analysis of selected polyphenols was performed. The sensory features and quality of the wines was assessed using a sommelier analysis based on The Wine & Spirit Education Trust guidelines. The results indicated that the seven-day maceration of the dehydrated grapes resulted in the highest polyphenol content, as well as the largest antioxidant and antiradical contents. The oenological evaluation of wines produced by the Tokaj method and Italian passito method with seven-day maceration found that the wines were appreciated due to their rich taste, flavor, and overall quality. The present study confirms the promising opportunities to obtain special sweet wine with a valuable composition and oenological characteristics in regions with cooler climates.

Redox and Hormonal Changes in the Transcriptome of Grape (Vitis vinifera) Berries during Natural Noble Rot Development.

Noble rot is a favorable form of the interaction between grape (Vitis spp.) berries and the phytopathogenic fungus Botrytis cinerea. The transcriptome pattern of grapevine cells subject to natural noble rot development in the historic Hungarian Tokaj wine region has not been previously published. Furmint, a traditional white Tokaj variety suited to develop great quality noble rot was used in the experiments. Exploring a subset of the Furmint transcriptome redox and hormonal changes distinguishing between noble rot and bunch rot was revealed. Noble rot is defined by an early spike in abscisic acid (ABA) accumulation and a pronounced remodeling of ABA-related gene expression. Transcription of glutathione S-transferase isoforms is uniquely upregulated, whereas gene expression of some sectors of the antioxidative apparatus (e.g., catalases, carotenoid biosynthesis) is downregulated. These mRNA responses are lacking in berries exposed to bunch rot. Our results help to explain molecular details behind the fine and dynamic balance between noble rot and bunch rot development.

Evaluation of physicochemical, sensory, and antimicrobial properties of small-scale produced fruit vinegars

AbstractHungarian fruit vinegars were characterised in terms of physicochemical attributes (total polyphenol content, antioxidant characteristics/FRAP, CUPRAC, ABTS/, ascorbic acid content, pH, total soluble solids), sensory profiles, and antimicrobial properties.Both compositional and sensory profiles showed distinct patterns depending on the type of vinegar (Tokaj wine, balsamic or apple) and the additional fruit used. Balsamic vinegars maturated on rosehip, sea buckthorn, and raspberry showed outstanding antioxidant performances. Rosehip, raspberry, and quince vinegars, as well as vinegars produced from Tokaji aszú and balsamic apple obtained high scores for fruity and sweet notes.Antimicrobial activities were tested on Gram-negative and Gram-positive organisms, including probiotic bacteria. Generally, only weak activities were obtained, which was attributed to the natural sugar content of the samples, depending on the type of the vinegar and the fruit. Similar results, but more pronounced bacterial growth inhibitions were obtained for probiotic strains, however, some probiotic strains were resistant to at least two of the vinegars. Based on these, balsamic apple, raspberry, rosehip, quince, and sea buckthorn may qualify as potential functional components of probiotic preparations containing some of the strains tested.