Search Results (8)

The chemical profiles of young and mature wines produced from three grape varieties Merlot, Mavrud, and Sauvignon blanc were analyzed using ¹H nuclear magnetic resonance (NMR) spectroscopy and advanced statistical methods. Furthermore, grape ales―a hybrid of beer and wine—were subjected to analysis to facilitate a comparison of their composition with that of traditional wines. The analysis yielded a total of 37 compounds, which were identified and quantified. Orthogonal partial least squares discriminant analysis (OPLS-DA) models were employed to distinguish the chemical profiles of young and mature wines, as well as those of grape ales. The findings demonstrate that the fermentation and aging processes result in the formation of distinctive chemical signatures in wines, with key compounds such as shikimic acid and fructose contributing to this differentiation. The identified compounds comprise seven alcohols (2,3-butanediol, glycerol, 2-methylpropan-1-ol, 3-methyl-butan-1-ol, myo-inositol, 1-propanol, 2-phenylethanol), six organic acids (galacturonic, citric, lactic, malic, shikimic, succinic), three amino acids (alanine, proline, tyrosine), four sugars (arabinose, fructose, galactose, glucose), coutaric acid, and acetoin. The levels of these 22 components enabled the successful differentiation of young and mature wines among the three grape varieties. These findings underscore the substantial chemical distinctions between grape ales and wines, thereby emphasizing the potential of grape ales as an innovative fermented beverage. Full article

The popular appreciation of dry white wines is most frequently directed to young wines. However, present consumption trends comprise the valorisation of aged dry white wines. Therefore, the present work was aimed at the sensory analysis of aged dry white wines to define their sensory space and to understand which factors drive their quality evaluation by experienced tasters (critics, oenologists and students). Individuals were asked to evaluate several synthetic and aesthetic attributes and to characterise the analytic sensory profile through a Check-All-That-Apply (CATA) methodology. The quality evaluations were differently correlated with wine synthetic parameters according to the taster group. For both critics and oenologists, overall quality scores were driven by persistence and complexity. Moreover, quality was also highly correlated with power for critics and with balance for oenologists. Quality scores were highly correlated with wine browning (absorbance at 420 nm) for critics. The tasting panel showed a homogeneous analytic description of aroma, taste and mouthfeel consistent with wine age. The different ages could be associated with a continuous sensory space characterised by a decreasing perception of freshness and an increase in mature and mellowed descriptors. All wines shared an austere in-mouth perception elicited by their acidity, saltiness, bitterness, smoothness and dryness. The age prediction showed that most tasters failed to guess the aged wines that were more than roughly 13 years old, indicating that tasters were not familiar with the sensory features of white wines from 17 to 46 years old. In conclusion, experienced tasters consistently described the sensory space and recognised the high quality of aged dry white wines. Education programs may use the defined sensory spaces according to aging and to expand the range of quality perception by consumers. Full article

Rosé wines are commonly consumed as young wines mainly due to their freshness and fruity character. Nevertheless, in recent years a new market looking for alternatives to traditional wines has emerged. Considering this, the study of the volatile and sensory profiles of a varietal rosé wine aged with oak chips was carried out. Two Cabernet Sauvignon rosé wines were made: one was maturated with oak chips and the other without. Both wines were physicochemically characterized. Then, their volatile and sensory profiles were analyzed, also including two commercial wines. The results showed that the produced wines complied with Mexican regulations. Also, they showed greater relative areas in compounds such as ethyl (E)-2-hexenoate, ethyl heptanoate, ethyl nonanoate, ethyl 3-nonenoate, β-citronellol, (±)-trans-nerolidol, and β-damascenone. In their sensory profile, they were mostly related to attributes such as berries, prune, bell pepper, and herbaceous notes. Among the compounds related to barrel maturation, only cis-oak-lactone was identified in the rosé wine matured with chips. However, it was associated with vanilla, woody, smoky, and spicy attributes. According to the results, the maturation of rosé wines with oak chips could be a good alternative to provide them with unusual notes and thus offer new alternatives to traditional and new wine consumers. Full article

Grapevine leafroll-associated virus 3 (GLRaV-3) is one of the most important viruses affecting global grape and wine production. GLRaV-3 is the chief agent associated with grapevine leafroll disease (GLRD), the most prevalent and economically destructive grapevine viral disease complex. Response of grapevine to GLRaV-3 infection at the gene expression level is poorly characterized, limiting the understanding of GLRaV-3 pathogenesis and viral-associated symptom development. In this research, we used RNA-Seq to profile the changes in global gene expression of Cabernet franc, a premium red wine grape, analyzing leaf and berry tissues at three key different developmental stages. We have identified 1457 differentially expressed genes (DEGs) in leaves and 1181 DEGs in berries. The expression profiles of a subset of DEGs were validated through RT-qPCR, including those involved in photosynthesis (VvPSBP1), carbohydrate partitioning (VvSUT2, VvHT5, VvGBSS1, and VvSUS), flavonoid biosynthesis (VvUFGT, VvLAR1, and VvFLS), defense response (VvPR-10.3, and VvPR-10.7), and mitochondrial activities (ETFB, TIM13, and NDUFA1). GLRaV-3 infection altered source–sink relationship between leaves and berries. Photosynthesis and photosynthate assimilation were inhibited in mature leaves while increased in young berries. The expression of genes involved in anthocyanin biosynthesis increased in GLRaV-3-infected leaves, correlating with interveinal tissue reddening, a hallmark of GLRD symptoms. Notably, we identified changes in gene expression that suggest a compromised sugar export and increased sugar retrieval in GLRaV-3-infected leaves. Genes associated with mitochondria were down-regulated in both leaves and berries of Cabernet franc infected with GLRaV-3. Results of the present study suggest that GLRaV-3 infection may disrupt mitochondrial function in grapevine leaves, leading to repressed sugar export and accumulation of sugar in mature leaf tissues. The excessive sugar accumulation in GLRaV-3-infected leaves may trigger downstream GLRD symptom development and negatively impact berry quality. We propose a working model to account for the molecular events underlying the pathogenesis of GLRaV-3 and symptom development. Full article

Grapevine leafroll disease (GLD) constrains wine production worldwide. In New Zealand, the main causal agent of GLD is grapevine leafroll-associated virus 3 (GLRaV-3). To control GLD, an integrated management program is used and includes removing (roguing) GLRaV-3-infected vines from the vineyard. The classical foliar symptoms from virus-infected red-berry cultivars are leaves with dark red intervein, green veins, and downward rolling of margins. Growers use these phenotypic cues to undertake visual symptom identification (VSI) for GLD. However, the influence of the known large genetic variation among GLRaV-3 isolates on the foliar symptoms from different grapevine cultivars remains undescribed, especially in cool-climate growing environments, such as New Zealand. Over three vintages (2015, 2016, and 2017), VSI for GLD was undertaken at three field sites in New Zealand (Auckland, Hawke’s Bay, and Marlborough), each including four cultivars (Merlot, Pinot noir, Sauvignon blanc, and Pinot gris) infected with three GLRaV-3 genotypes (Groups I, VI, and X) or GLRaV-3-uninfected control plants. Throughout this study, no visual symptoms were observed on white-berry cultivars infected with GLRaV-3. For red-berry cultivars, the greatest variability in observed foliar symptoms among regional study sites, cultivars, and GLRaV-3 genotypes was observed early in the growing season. In particular, Group X had significantly delayed symptom expression across all three sites compared with Groups I and VI. As the newly infected, young vines matured in years 2 and 3, the GLRaV-3 genotype, cultivar, region, and environmental conditions had minimal influence on the accuracy of VSI, with consistently high (>95%) within-vintage identification by the end of each vintage. The results from this study strongly support the use of VSI for the GLD management of red-berry cultivar grapevines, Merlot and Pinot noir, as a reliable and cost-effective tool against GLD. Full article

Renewed interest in varieties that are more tolerant to diseases has emerged, which is mainly due to increased awareness by producers and consumers regarding the impact of phytochemicals in the environment. This paper describes the first Slovenian grapevine variety ‘Pinore’ crossed between the Vitis vinifera L. ‘Pinot Noir’ clone Mf and ‘Regent’ vines. The aim was to create an early ripening grape cultivar that has a good tolerance to biotic stress (e.g., downy and powdery mildew, botrytis) combined with the benefits of established cultivars and their intense wine colors. Some ampelographic characteristics of young shoots, mature leaves, bunches, and berries are presented, and its major agronomic traits, ripening time, grape yield, quality performances, and disease resistance were evaluated over a three-year period (2014–2017). Wine sensory analyses were performed and compared with the international variety ‘Pinot Noir’. The examined genotype showed good agronomic performance and a high wine quality as far as the content of polyphenols is concerned, especially in terms of anthocyanins and tolerance to diseases (Ren3/9 and Rpv3.1); it is significantly different compared to the reference variety ‘Pinot Noir’. In terms of ampelographic characteristics, the main differences are in the number of leaf lobes, the depth of the lateral sinuses, and the content of anthocyanins in its flesh. The investigated genotype has been proposed to the Committee of new varieties in Slovenia for the variety recognition procedure, and completion of the procedure planned for the end of 2023. Full article

Polyphenols, especially anthocyanins, play an important role on red wine sensory qualities and their evolution during storage. High Power Ultrasound (HPU) has been recognized as one of the most promising technologies which can be applied in winemaking processes for several purposes, and it is recently officially approved for crushed grapes treatments. The effect of ultrasound amplitude (41 and 81%) and treatment time (1, 3, and 5 min) has been studied on anthocyanins, flavan-3-ols, tannins, polymerized pigments, HCl index, and the color intensity of two finished red young wines. Anthocyanins and phenols compounds were not degraded with an increase in amplitude and sonication time, and the chromatic properties of the selected wines were preserved. Amplitude and ultrasound time were also evaluated considering their effect on evolution of anthocyanin content and phenolic stability indices during the first thirty days of storage. The higher level of amplitude (81%) induced a higher percentage decrease in tannins, 15% and 40% after 15 and 30 days of storage, respectively, compared to untreated wine which did not show a significant change during storage. HPU shows a possible chemical effect on the evolution of some analytical indices during bottling maturation, but their effectiveness could be strictly linked with the initial phenolic profile and ratios between polyphenol classes. Full article

Originating in the grapes, anthocyanins and their derivatives are the crucial pigments responsible for the red wine color. During wine maturation and aging, the concentration of monomeric anthocyanins declines constantly, while numerous more complex and stable anthocyanin derived pigments are formed, mainly including pyranoanthocyanins, polymeric anthocyanins produced from condensation between anthocyanin and/or flavan-3-ols directly or mediated by aldehydes. Correspondingly, their structural modifications result in a characteristic variation of color, from purple-red color in young red wines to brick-red hue of the aged. Because of the extreme complexity of chemical compounds involved, many investigations have been made using model solutions of know composition rather than wine. Thus, there is a large amount of research still required to obtain an overall perspective of the anthocyanin composition and its change with time in red wines. Future findings may well greatly revise our current interpretation of the color in red wines. This paper summarizes the most recent advances in the studies of the anthocyanins derived pigments in red wines, as well as their color evolution. Full article