Wine Varieties Research Articles

THE IMPACT OF ULTRASOUND TREATMENT ON THE QUALITY OF DIFFERENT WINE VARIETIES

The aim of the present study was to characterize the quality of four varieties of wines obtained from grapes of Vrancea area: Feteasca Alba (FA), Tamaioasa Romaneasca (TR), Cabernet Sauvignon (CS) and Muscat Hamburg (MH) ultrasonicated (US) at different times (10 and 30 minutes), in terms of physico-chemical and sensory properties. The sensory characteristics (clarity, color, aroma, taste) and the physicochemical properties (density, sugar and alcohol content, pH, acidity, electrical conductivity, turbidity) were determinated on must and wine samples. Sonicated wine (energy intake in liquid) gives a more uniform degree of dispersion to the components, which improves the taste and quality (intensification of the color, flavor, and taste of the wine by extracting valuable ingredients from grape seeds and skin, such as polyphenolic substances), but also accelerates its maturation. The results revealed that the ultrasonic samples had a lower fermentation rate due to the inactivation of the yeasts.The wines have a more intense color than the untreated samples, results also related by physico-chemical parameters tested.

Precursors consumption preferences and thiol release capacity of the wine yeasts Saccharomyces cerevisiae, Torulaspora delbrueckii, and Lachancea thermotolerans

The aromatic profile of wine determines its overall final quality, and among the volatile molecules that define it, varietal thiols are responsible for shaping the distinctive character of certain wine varieties. In grape must, these thiols are conjugated to amino acids or small peptides in a non-volatile form. During wine fermentation, yeasts play a principal role in expressing these aromatic compounds as they internalise and cleavage these precursors, releasing the corresponding free and aroma-impacting fraction. Here, we investigate the impact of three wine yeasts (Saccharomyces cerevisiae, Torulaspora delbrueckii and Lachancea thermotolerans) on thiol releasing in synthetic grape must fermentations supplemented with different cysteinylated (Cys-4MSP and Cys-3SH) and glutathionylated (GSH-4MSP and GSH-3SH) precursors. We demonstrate higher consumption levels of cysteinylated precursors, and consequently, higher amounts of thiols are released from them compared to glutathionylated ones. We also report a significant impact of yeast inoculated on the final thiols released. Meanwhile T. delkbrueckii exhibits a great 3SHA releasing capacity, L. thermotolerans stands out because of its high 3SH release. We also highlight the synergic effect of the co-inoculation strategy, especially relevant in the case of S. cerevisiae and L. thermotolerans mixed fermentation, that has an outstanding release of 4MSP thiol. Although our results stem from a specific experimental approach that differs from real winemaking situations, these findings reveal the potential of unravelling the specific role of different yeast species, thiol precursors and their interaction, to improve wine production processes in the context of wine aroma enhancement.

Transcriptome and Metabolome Analyses of Aroma Differences between Chardonnay and a Chardonnay Bud Sport.

Chardonnay is one of the most popular white grape wine varieties in the world, but this wine lacks typical aroma, considered a sensory defect. Our research group identified a Chardonnay bud sport with typical muscat characteristics. The goal of this work was to discover the key candidate genes related to muscat characteristics in this Chardonnay bud sport to reveal the mechanism of muscat formation and guide molecular design breeding. To this end, HS-SPME-GC-MS and RNA-Seq were used to analyze volatile organic compounds and the differentially expressed genes in Chardonnay and its aromatic bud sport. Forty-nine volatiles were identified as potential biomarkers, which included mainly aldehydes and terpenes. Geraniol, linalool, and phenylacetaldehyde were identified as the main aroma components of the mutant. The GO, KEGG, GSEA, and correlation analysis revealed HMGR, TPS1, TPS2, TPS5, novel.939, and CYP450 as key genes for terpene synthesis. MAO1 and MAO2 were significantly downregulated, but there was an increased content of phenylacetaldehyde. These key candidate genes provide a reference for the development of functional markers for muscat varieties and also provide insight into the formation mechanism of muscat aroma.

Use of Non-Destructive Ultrasonic Techniques as Characterization Tools for Different Varieties of Wine.

In this work, we have verified how non-destructive ultrasonic evaluation allows for acoustically characterizing different varieties of wine. For this, a 3.5 MHz transducer has been used by means of an immersion technique in pulse-echo mode. The tests were performed at various temperatures in the range 14-18 °C. The evaluation has been carried out studying, on the one hand, conventional analysis parameters (velocity and attenuation) and, on the other, less conventional parameters (frequency components). The experimental study comprised two stages. In the first, the feasibility of the study was checked by inspecting twelve samples belonging to six varieties of red and white wine. The results showed clearly higher ultrasonic propagation velocity values in the red wine samples. In the second, nine samples of different monovarietal wine varieties (Grenache, Tempranillo and Cabernet Sauvignon) were analyzed. The results show how ultrasonic velocity makes it possible to unequivocally classify the grape variety used in winemaking with the Cabernet Sauvignon variety having the highest values and the Grenache the lowest. In addition, the wines of the Tempranillo variety are those that present higher values of the attenuation coefficient, and those from the Grenache variety transmit higher frequency waves.

Shelf life determination of two palm wine varieties and its effect on biochemical properties and enzyme production.

In palm wine, the available complex microbiota plays very vital roles in the general attributes of the beverage as well as the significance of the various metabolites generated. This research focused on evaluating the biochemical properties of the palm wine obtained from two different varieties of oil palm (Elaeis guineensis) and its potential enzyme activity, as well as assessing the effect of the changes that occur during the keeping time. The biochemical contents (alcohol, total titratable acid, reducing sugar, and pH) were evaluated every 2 h over a period of 144 h. The palm wine varieties were also analyzed for cellulase and amylase production. There was an increase in ethanol for both varieties from 7.29±0.02% (1 h) to 14.82±0.02 (144 h) for variety 1, and from 8.35±0.01% (1 h) to 16.32±0.03% (144 h) for variety 2; the TTA increased with keeping time from 2.25±0.03% (1 h) to 4.42±0.03% (144 h) for variety 1, and from 2.35±0.02% (1h) to 5.01±0.04 (144 h) for variety 2. Reducing sugar decreased from 476.58±0.04 mg/L (1 h) to 42.84±0.75 mg/L (144 h) for variety 1, while variety 2 decreased from 238.18±0.05 mg/L (1 h) to 43.73±0.63 mg/L (144 h). The pH of the palm wine also experienced a decrease for variety 1 from 5.2±0.06 at 1 h to 2.8±0.17 at 144 h, while the variety 2 decreased from 4.8±0.17 at 1 h to 2.8±0.1 at 144 h. There was a reduction in the sugar content with the accumulation of alcohol, which occurred in both varieties, and a drop in the pH due to an increase in organic acids. The palm wine varieties were screened for cellulase and amylase activity, with the highest amylase yield for varieties 1 and 2 at 0.62 U/ml and 0.21 U/ml, respectively on the first day, while that of cellulase was observed at 48 h (0.34 U/ml) for V1 and at 1 h (0.2 U/ml) for V2. The result of this current study proves the importance of the microbial consortium in fresh palm wine as well as its potential as a source of enzyme production, and also shows that these parameters are affected by the keeping time.

Bunch thinning and its influence on the shoots growth dynamics in some syrah wine variety clones

During the period 2020-2022, an experiment was conducted in the experimental vineyard of the Agricultural University – Plovdiv, and four clones of the wine variety Syrah, numbered 100, 174, 470 and 524, grafted on the SO4 rootstock were selected as the study object. During the „pea size“ phase, the green pruning operation – bunch thinning was applied. The shoots growth starts from the vegetation phase „first leaf appearance“ and ends at the „veraison“. The average duration is about 100 days, covering the period of May, June and July. It was found that the vine shoots from a clone 470 reached the greatest average length, V3 – 285, 265, 290 cm and V7 – 359, 336, and 380 cm, and those from a clone 100 were distinguished by the weakest growth, V1 – 197, 203 and 205 cm and V5 – 240, 228 and 245 cm. Differences were proven between the variants, both in the non-reduced (V1, V2, V3, and V4) and in those with reduced yields (V5, V6, V7, and V8), as after reducing the number of bunches, the length of the shoots was longer – high in all vines from the used Syrah clones. This study provides information on the relationship between the applied green pruning operation (bunch thinning) during the growing season and its effects on the vegetative growth. Balancing the vines bud load by controlling yield during the growing season is a preferred viticultural practice for increasing the grape quality. Keywords: Clones, Syrah, green pruning, bunch thinning, shoot growth

Targeted analysis for the detection of phenolics and authentication of Albanian wines using LC-DAD/ESI–MS/MS combined with chemometric tools

In recent years, Albania has seen a significant increase in wine production, which can be attributed to the growing interest in the diversity of native grape varieties. Among the most popular grape varieties are Kallmet, Shesh i zi (ShiZ), Shesh i bardhë (ShiB), and Cerruje, which are known for their distinctive wines as well as the planted area. A study was conducted to investigate the influence of the territory and vintage on phenolic compounds of single-variety wines from these grape varieties. Liquid chromatography identified and quantified thirty-one phenolic compounds, sub-grouped into flavonoids and non-flavonoids, with diode-array detection coupled to electrospray ionization tandem mass spectrometry (LC–DAD–ESI/MSn). Within the red wines group, the ShiZ variety wine presented the highest phenolic content (1037 mg/L), followed by Kallmet cv. (539 mg/L); conversely, in the white wine group, the ShiB wines (699 mg/L) were distinguished from the Cerruje variety. Gallic acid was the main phenolic compound, followed by procyanidin B3. ShiB and ShiZ had the highest levels, at 215 and 136 mg/L, respectively. Among flavanols, (+)-catechin was found in the highest levels, with the maximum in Kallmet cv. red wine (58.9 mg/L), followed by (-)-epicatechin (29.1 mg/L). The ShiB wine had the highest content of flavonols, with quercetin-3-O-glucuronide and quercetin-3-O-glucoside as the main contributors. The highest quantity of stilbenoids belonged to Kallmet red wine (1.59 mg/L). Applying Principal Component Analysis (PCA) in red and white wine groups made a good separation possible according to variety and region. However, a separation according to vintage year was not successful.

The Valorization of Spanish Minority Grapevine Varieties—The Volatile Profile of Their Wines as a Characterization Feature

Despite the large number of existing varieties of Vitis vinifera L., only few occupy a large niche in today’s highly globalized wine market. The increasing consumer demand for diversified products, as well as the changing climatic conditions, make establishing a process of varietal diversification essential to achieve both challenges. It is for this reason that the study of minority varieties, which have a higher level of adaptation to each area of origin, is of particular interest. With the main objective of achieving an in-depth knowledge of minority varieties in Spain, the national research project ‘Valorization of Minority Grapevine Varieties for their Potential for Wine Diversification and Resilience to Climate Change’ (MINORVIN), has been proposed. Within this extensive project, the present study describes the aroma profiles of 60 single-variety wines, corresponding with 44 different varieties, with 12 of these varieties being studied at the same time in several Spanish regions. Volatile compounds were determined through three consecutive vintages using gas chromatography-mass spectrometry (GC-MS) and gas chromatography–flame ionization detector (GC-FID). Compounds were grouped into major compounds, including alcohols, C6 compounds, esters, acetates, acids, carbonyl compounds, and other type of compounds, and minor compounds, including lactones, terpenes, and C13-norisoprenoids, according to their concentration in the wines being analyzed. Among this last group of compounds, lactones were quantitatively the most abundant, followed by terpenes. This study reflects that minority variety wines show distinctive aromatic profiles, supporting the importance of valuing and promoting the autochthonous minority grapevine varieties for the Spanish winemaking industry.

Strategies for Global Promotion of Chinese Yellow Wine: History, Present, and Future Development

Huangjiu, or Chinese Yellow Wine, is a significant cultural heritage item in China, with a long history and traditional brewing techniques. This paper examines the historical significance of Huangjiu, its current market position, and potential strategies for global promotion. Historically, yellow wine has played a pivotal role in Chinese society, being used in rituals, celebrations, and as a medicinal beverage. The production methods, which have been in use for over 3,000 years, contribute to the distinctive flavors and health benefits of the beverage. Currently, Yellow Wine has a robust domestic market driven by cultural preferences and health perceptions. However, it faces challenges in international expansion. These challenges include regulatory barriers, cultural differences, and competition from established wine producers such as those in France, Italy, and Spain. To enhance global brand recognition, it would be beneficial to leverage Chinese cultural events and collaborate with international wine experts. It is essential to improve the legal and regulatory frameworks by establishing standardized quality processes and providing tax incentives. This will facilitate exports and maintain the authenticity of the product. It is imperative that product development innovates, creating new wine varieties and sustainable production methods, to cater to the diverse global market and align with the prevailing sustainability trends. The promotion of Yellow Wine may also be facilitated by the expansion of wine tourism through initiatives such as the establishment of wine theme parks, which would offer visitors immersive cultural experiences. The following recommendations are proposed for stakeholders to consider firstly, producers should focus on quality and innovation; secondly, marketers should develop targeted marketing campaigns; and thirdly, supportive regulatory environments should be created. Further research should investigate the potential health benefits of Yellow Wine, consumer behavior in different regions, and its integration into modern culinary practices. The prospective evolution of Chinese Yellow Wine necessitates a comprehensive strategy that addresses quality, innovation, marketing, and regulatory challenges. By leveraging its distinctive cultural heritage and overcoming obstacles to international expansion, Chinese Yellow Wine can achieve sustained growth and global success. This study highlights the importance of integrating traditional cultural products into the global market to preserve heritage and drive economic growth.

Sensory profile and chemical quality of Merlot aged in barrels of different wood species

The cultivation of Vitis vinifera varieties in Brazil was established in 1970. With the opening of the market to imported labels and a greater variety of wines, viticulture became more competitive, and consumers became more demanding. The aging of wine is a system that involves several reactions based on the extraction of molecules from the wood and also on the micro-oxygenation of beverages. The objective of this study was to investigate the sensorial and chemical evolution of wines aged in barrels of different woods: French oak (Quercus petraea), Amburana (Amburana cearensis), and Jequitibá Rosa (Cariniana legalis). The comparison of the sensorial and chemical characteristics of the aged wine with the non-aged one allowed us to know the modifications resulting from the maturation time. Their distinct evolution among the different species was identified through chromatographic analysis of maturation congeners. Perceived sensory characteristics and acceptance of Brazilian woods were measured using the Napping and UltraFlash Profile methodologies. Tropical woods stood out in terms of acceptance by tasters, and the sensory attributes listed by the panel differ between both.

Authentication of selected white wines by geographical origin using ICP spectrometric and chemometric analysis

An important aspect of assessing the authenticity of wines is its geographical origin. The aim of the work is to authenticate by geographical origin according to the data of the ICP-spectrometric and chemometric analysis of elemental "images" of wines produced from white grape varieties Chardonnay, Riesling and Muscat grown in four regions of the Krasnodar Territory, Russia. The difference in the contents of Al, Ba, Ca and Rb in wines was found depending on the variety, and Al, Ba, Rb, Fe, Li, Sr – depending on the region of grape growth. Different models of the experimental data processing were used for attribution of the produced varieties of wine to the area of the grape's growth. The criterion for the quality of the constructed models was the accuracy of the attribution of a wine variety to the area of the grape's growth (%). Analysis of the elemental analysis data of 153 wine samples showed that in terms of attribution accuracy, automated neural networks (100 %) are preferred among machine learning methods, followed by support vector machines (98.69 %) and general discriminant analysis (94.77 %). The applied mathematical models enabled the revealing of the cluster structure of the analyzed wine varieties and their attribution to the area of a grape growth with high accuracy. Sr, Li and Fe concentrations in wines were found as the dominating predictors in the constructed models for definition of the geographical origin of wines. The combination of ICP-spectrometric analysis data with the capabilities of statistical modeling of machine learning methods focused on large-dimensional data made it possible to successfully solve small-dimensional problems of the definition of the geographical origin of wines by their elemental composition and variety.

Estimation of Chemical Compounds in Selected Italian and French Wines Produced through Organic and Conventional Methods

In this study, Italian and French wines produced through organic and conventional methods were analyzed. Three different varieties of wines were examined, including Cabernet Sauvignon, Merlot, and Syrah. Individual compounds were quantitatively and qualitatively analyzed to measure their levels of organic acids and polyphenols, such as phenolic acids, flavonoids, and anthocyanins, as well as their different chemical fractions. Among the French wines, organic varieties contained significantly higher levels of lactic and acetic acids, as well as catechins and rutin, compared to those of their conventional counterparts. Based on its chemical components, one of the best wines in this group was Syrah. In contrast, similar results were observed for the Italian wine produced by both systems. One type of Italian wine with superior results was Cabernet Sauvignon.

Conductive polymer-based modified electrode for total antioxidant capacity determination

A poly(3,4-ethylenedioxythiophene)-modified glassy carbon electrode (PEDOTvx/GCE) was prepared by electropolymerization at different scan rates (v) from a monomer EDOT solution by co-doping with an organic dopant (sodium dodecyl sulphate, SDS) and an inorganic compound (LiClO4). The PEDOTv10/GCE modified electrode, which exhibited the highest surface area, was investigated by cyclic voltammetry (CV) at different scan rates or pHs of electrolyte solution, and by differential pulse voltammetry (DPV). The electrochemical and electroanalytical parameters were expressed using caffeic acid, a reference substance. The new modified electrode was used to estimate the antioxidant activity (AA) in different varieties of wines (white, rose, and red). For all types of wines, a good correlation between AA results obtained by electrochemical and spectrophotometrically FRAP assay was obtained.

The agroecological potential of clones of Merlot variety

The research presented in this article consists in studying the agroecological potential of the clones of Merlot wine variety (cl. 181, cl. 343, cl. 347, cl. 348, cl. 349) under the conditions of the Mereni wine-growing center, Codru region. The climate changes of recent years have brought more and more challenges to the farmers to study and better understand how high temperatures affect the vine and not only. Increasing variety diversity is an important task that involves both enhancing the quality of selection and improving the varieties themselves. This study presents the results of a research on a series of clones of Merlot grape variety. The evolution of the main phenological phases of the vine vegetation cycle was directly influenced by the climatic, pedological and topographical conditions of the area. Based on the study, it was found that in the conditions of the Mereni wine-growing area, the Codru Region, the mentioned clones of Merlot wine variety recorded a various level of significance of the difference in the values of the analyzed characters, depending on the year and the clone. The Merlot cl. 347 showed a maximum harvest of 18.08 t/ha. The Merlot cl. 348 showed a maximum sugar content of 264.5 g/dm3. The Merlot cl. 347 showed a minimum content of titratable acidity of 8.32 g/dm3.

Electrochemical fingerprinting of complex solutions using boron-doped diamond electrodes: Advanced classifications by machine learning

Boron-doped diamond (BDD) electrochemical sensors exhibit high sensitivity and a wide-ranging voltammogram scan capability, facilitating the generation of unique fingerprinting information. These attributes are invaluable for the rigorous quality control and real-time monitoring of intricate liquid compositions. In this study, we present an advanced approach for the authentication of complex liquid using BDD electrochemical sensors, in conjunction with Principal Component Analysis (PCA) and Support Vector Machine (SVM) algorithms. Leveraging the heightened sensitivity of BDD sensor signals, it was demonstrated 96 % accuracy rate in authenticity assessments from 21 distinct varieties of red wines. Additionally, high accuracy of classification by grape varieties was demonstrated using electrochemical fingerprints combined with machine learning. Our novel non-specific electronic tongue system offers multimodal electrochemical fingerprinting, ensuring fast and user-friendly measurements without relying on sensor arrays.

Diplodia seriata Biocontrol Is Altered via Temperature and the Control of Bacteria.

Grapevine trunk diseases (GTDs) attack the vine's wood, devastating vineyards worldwide. Chile is the world's fourth-largest wine exporter, and Cabernet Sauvignon is one of the most economically important red wine varieties. Botryosphaeria dieback is an important GTD, and Diplodia seriata is one of the main pathogenic species. Biocontrol studies of these pathogens are commonly carried out at different incubation times but at a single temperature. This study aimed to evaluate the biocontrol effect of Chilean PGPB and grapevine endophytic bacteria against D. seriata at different temperatures. We analyzed the biocontrol effect of Pseudomonas sp. GcR15a, Pseudomonas sp. AMCR2b and Rhodococcus sp. PU4, with three D. seriata isolates (PUCV 2120, PUCV 2142 and PUCV 2183) at 8, 22 and 35 °C. Two dual-culture antagonism methods (agar plug diffusion and double plate) were used to evaluate the in vitro effect, and an in vivo test was performed with Cabernet Sauvignon cuttings. In vitro, the greatest inhibitions were obtained using the agar plug diffusion method and at a temperature of 8 °C, where Rhodococcus sp. PU4 obtains a 65% control (average) and Pseudomonas sp. GcR15a a 57% average. At 22 °C, only strains of Pseudomonas sp. show control. At 35 °C, one Pseudomonas strain shows the highest control (38%), on average, similar to tebuconazole (33%), and then Rhodococcus sp. (30%). In vivo, a biocontrol effect is observed against two D. seriata isolates, while the PUCV 2142 proves to be more resistant to control. The biocontrol ability at low temperatures is promising for effective control in the field, where infections occur primarily in winter.

Decoding Therapeutic Applications of Quercetin: Recent Advancements in Nanotechnological Strategies.

For centuries, people have used herbal medicine to treat a diversity of health complications and as a natural substance, they have a favourable effect on our health. Herbal ingredients can be utilized as lead molecules in the innovation and development of a new drug. Flavonoids are a class of chemical compounds with diverse phenolic structures, and they are found in a wide variety of foods, including fruits, vegetables, cereals, bark, roots, stems, flowers, tea, and wine. Quercetin is the most prevalent polyphenolic bioflavonoid or flavonoid. Quercetin is found in many food products and has demonstrated a wide range of pharmacological activities, including the treatment of allergies, ocular diseases, metabolic ailments, inflammatory illnesses, cardiovascular ailments and arthritis. Quercetin has attracted interest as an emerging pharmacophore with the potential to significantly advance research and the development of novel therapeutic medicines for a variety of diseases. Despite having a huge therapeutic potential, these flavonoids have unfavourable pharmacokinetic characteristics, low bioavailability, and poor solubility, limiting their application in therapeutics. The objective of the current study is to present a new update on the major therapeutic uses of quercetin and other types of nanocarriers that contain quercetin to treat various ailments.

Effect of indigenous Saccharomyces cerevisiae strains on microbial community successions and volatile compounds changes during Longyan wine fermentation

In Longyan grape, as a unique white wine variety in China, the connection between starters and wine flavor is poorly understood. Thus, this study compared the effects of commercial yeast VL2 and three selected native Saccharomyces cerevisiae strains on the microbial community and volatile compounds during alcohol fermentation of Longyan wine. Results showed that the indigenous yeast strain FMS can initiate fermentation faster than other strains. A total of 60 aromatic compounds were identified in all fermentation samples, and the concentration of volatile compounds in wines inoculated with FMS (9619.61 ± 500.18 μg/L) was significantly higher than in VL2 wines (8358.91 ± 131.48 μg/L). Moreover, the microbial diversity differed among the four strains, with the FMS fermentation samples having the highest microbial genus of 470. The core microorganisms of VL2 (13), JCT (15), FMS (18), and FML (12) wines were identified using OPLS analysis and Spearman's correlation analysis, respectively. Among them, Lactobacillus, Paenibacillus, and Pichia were the unique microorganisms in FMS wines, which performed a crucial part in the synthesis of aromatic compounds such as hexyl acetate, ethyl butanoate, ethyl octanoate, and ethyl 9-decenoate. Therefore, FMS wines has effectively improved the quality of the wines and diversified the organoleptic quality of Longyan wines from Huaizhuo Basin. This study provided useful references for understanding the role of brewing yeast in the formation of flavor compounds during the fermentation process of Longyan dry white wine, as well as the application of indigenous brewing yeast in the wine industry.

Pilot Scale Continuous Pulsed Electric Fields Treatments for Vinification and Stabilization of Arinto and Moscatel Graúdo (Vitis vinifera L.) White Grape Varieties: Effects on Sensory and Physico-Chemical Quality of Wines

Pulsed electric field (PEF) processing of white grapes (Arinto, Moscatel Graúdo also known as Moscatel de Setúbal) before pressing for must extraction (1.2 and 1.6 kV/cm) and before bottling for finished wine physical stabilization (10 kV/cm) was implemented in a pilot-scale winery to produce about 540 L of wine for each variety. PEF was applied at these two different stages of wine production, and its effects on the sensory and physico-chemical quality of the wines were investigated. The sensory triangle tests revealed no significant change in both wine varieties’ colour, odour, and taste with PEF extraction and PEF stabilization treatments. However, for colour coordinates assessed with a spectrophotometer, a significant increase in CIE b* colour coordinate was registered for PEF-extracted Arinto and Moscatel wine samples, showing a development of a more intense yellow colour. Concerning physico-chemical quality parameters, the PEF extraction increased both wine varieties’ turbidity and pH, although total acidity was not affected. The total phenols also increased in Arinto with extraction. The second PEF treatment applied for wine stabilization did not affect any of the quality parameters, except total phenols, which decreased in Moscatel wine. The results encourage the application of PEF in the wineries at different stages of vinification of white wine grape varieties.

Profiling factors, flavour parameters of port wines

In the multifaceted world of fortified sweet wines, port wines occupy a special place. Authentic Porto is a group of wines that is the hallmark of Portugal's unique wine region, which stretches along the picturesque valley of the Douro River. The name "Porto" regulated by European legislation can only be worn by wines made from grapes grown and vinified in this fertile land. It is worth mentioning that port wines are among the elite of the best dessert wines in the world, harmoniously complementing both dessert dishes and acting as an independent delicacy. The variety of port wines amazes the imagination of connoisseurs of this noble drink. They differ in color (white, pink, red, brown), aging time (multiple of 10 years) and degree of sweetness (from dry to sweet). Inexperienced port wine lovers often face a situation when they purchase wine that does not meet their expectations. This may be due, among other things, to the fact that there are wines on the market that imitate authentic Porto, but have nothing in common with it except the name. Here lies an important point: in the Russian Federation, wines are traditionally produced under the name "Port Wine", however, in terms of their parameters, style and taste, they differ significantly from their Portuguese counterparts. It is quite difficult for consumers to understand these nuances. These wines are of a national Russian character, and according to European legislation, they cannot be exported abroad because they do not comply with strict regulations established for authentic Porto, in particular, by geographical designation of origin. In this regard, grounds are required for the correct classification of this group of wines in order to avoid uncertainty in their places of sale and subsequent consumer disappointment due to the discrepancy between the desired and real flavor palette of the purchased port. An important factor influencing the taste and aroma of port wines is not only the grape variety used in its production, but also the place where it is grown, and the process of aging the wine. Aging plays a key role in the formation of a flavor bouquet of port wines. For this purpose, the wine is aged for a long period of time in bottles, tanks, and the best - oak barrels. At the same time, the finished wines acquire unique aromatic and taste parameters. The duration of aging can vary from several years to several decades, depending on the desired style and quality of the port. During the aging process in oak barrels, port wines undergo a complex biochemical process that forms the unique aromas and taste of the wine. Oak barrels also make their natural contribution to the bouquet of wine, adding delicate woody notes that give port wines depth and complexity. Thus, port wine is not just wine, it is a real art that combines the skill of winemakers, the natural characteristics of grapes, as well as the unique conditions of viticulture and winemaking. Its rich bouquet and complex taste make the wine a unique and inimitable drink that can satisfy the most refined taste. The purpose of this article is an in-depth acquaintance with the nuances of the flavor parameters of this unique wine, as well as revealing the differences between authentic Porto and Russian port wines.