Search Results (244)

During red wine production, managing the pomace cap is key for a successful fermentation, allowing the extraction of phenolics and other metabolites and providing the necessary oxygen for yeast activity. In recent years, automatic cap management systems based on the injection of gases have gained popularity, despite the limited scientific information regarding the outcomes of their use. This trial aimed to evaluate the composition of wine during industrial red wine fermentations using an automatic sequential air injection system (i.e., AirMixing MI^TM). Fourteen lots of Cabernet Sauvignon grapes were fermented using four air injection regimes, where the intensity and daily frequency of air injections were set to either low or high. As expected, the treatment combining high-intensity and high-frequency air injection produced the largest dissolved oxygen peaks reaching up to 1.9 mg L⁻¹ per cycle, compared to 0.1 mg L⁻¹ in the low-intensity and low-frequency treatment. Yet, in all cases, little to no accumulation of oxygen overtime was observed. Regarding phenolics, the highest intensity and frequency of air injections led to the fastest increase in total phenolics, anthocyanins, short polymeric pigments, and tannin concentration, although compositional differences among treatments equilibrate by the end of fermentation. The main differences in phenolic compounds observed during fermentation were mediated by temperature variation among wine tanks. Based on these findings, it is advisable to keep the characterizing kinetics of phenolic extraction and expand the study to the aroma evolution of wines fermented with this technology. Full article

Rootstocks are widely used in viticulture as an agronomic measure to cope with biotic and abiotic stresses. In winegrapes, the aroma is one of the major factors defining the quality of grape berries and wines. In the present work, the grape aroma and wine aroma of Cabernet Sauvignon (CS) grafted on three rootstocks were investigated to inform the selection of rootstocks to utilize. 1103P, 5A, and SO₄ altered the composition of aromatic volatiles in CS grapes and wines. Among them, 5A and SO₄ had less effect on green leaf volatiles in the berries and wines, while 1103P increased green leaf volatile concentrations, up-regulating VvADH2 expression in both vintages. VvLOXA, VvLOXC, VvHPL1, VvADH1, VvADH2, and VvAAT were co-regulated by vintage and rootstock. Orthogonal partial least squares regression analysis (OPLS-DA) showed that the differential compounds in CS/1103P and CS berries were dominated by green leaf volatiles. Furthermore, the concentrations of 1-hexanol in the CS/1103P wines were significantly higher than in the other treatments in the two vintages. 1103P altered the expression of genes in the LOX-HPL pathway and increased the concentration of grape green leaf volatiles such as 1-hexanol and 1-hexanal, while vine vigor also affected green leaf volatile concentrations, the combination of which altered the aromatic composition of the wine and gave it more green flavors. Full article

The aim of this study was to investigate the effects of the crop load on the berry and wine composition of Marselan grapes. Thus, the appropriate crop load for Marselan wine grapes in Ningxia was determined based on the shoot density and the number of clusters per shoot. Marselan grapes from the Gezi Mountain vineyard, located at the eastern foot of Helan Mountain in the Qingtongxia region of Ningxia, were selected as the research material to conduct a combination experiment with four levels of shoot density and three levels of cluster density. The analysis of the berry and wine chemical composition was combined with a wine sensory evaluation to determine the optimal crop load levels. Crop load regulation significantly affected both the grape berry composition and the basic physicochemical properties of the resulting wine. Low crop loads improved metrics such as the berry weight and soluble solids content. A low shoot density facilitated the accumulation of organic acids, flavonols, and hydroxybenzoic acids in wine. Moderate crop loads were conducive to anthocyanin synthesis—the total individual anthocyanins content in the 10–20 shoots per meter of the canopy treatment group ranged from 116% to 490% of the control group—whereas excessive crop loads hindered its accumulation. Crop load management significantly influenced the aroma composition of wine by regulating the content of sugars, nitrogen sources, and organic acids in grape berries, thereby promoting the synthesis of esters and the accumulation of key aromatic compounds, such as terpenes. This process optimized pleasant flavors, including fruity and floral aromas. In contrast, wines from the high crop load and control treatments contained lower levels of these aroma compounds. Compounds such as ethyl caprylate and β-damascenone were identified as potential quality markers. Overall, the wine produced from vines with a crop load of 30 clusters (15 shoots per meter of canopy, 2 clusters per shoot) received the highest sensory scores. Appropriate crop load management is therefore critical to improving the chemical composition of Marselan wine. Full article

Color, aroma, and overall sensory quality in red wines are largely influenced by oxygen availability during fermentation. This study evaluated the effects of micro-oxygenation under hyperbaric conditions on the physicochemical, chromatic, volatile, and sensory properties of Vitis vinifera L. cv. Monastrell grape must. Grape clusters were manually harvested and fermented under controlled conditions, applying micro-oxygenation treatments at two fermentation stages (day 3 and day 13) within a hyperbaric chamber. Physicochemical analyses, CIELab color measurements, visible reflectance spectra, GC-FID volatile profiling, and descriptive sensory analysis were performed. Micro-oxygenated samples (M1_MOX and M2_MOX) showed significant increases in lightness (L*), redness (a*), chroma (C*), and reflectance in the 520–620 nm range, indicating enhanced extraction and stabilization of phenolic pigments. Volatile analysis revealed that these samples also contained higher concentrations of key esters and terpenes associated with fruity and floral notes. Sensory evaluation confirmed these findings, with MOX-treated wines displaying greater aromatic intensity, flavor persistence, and varietal character. Control samples (M1_CON and M2_CON) exhibited lower color saturation and volatile compound content, along with diminished sensory quality. These results suggest that hyperbaric micro-oxygenation is an effective strategy for improving color intensity and aromatic complexity during red wine fermentation under controlled, non-thermal conditions. Full article

Wine aroma is the result of the association of numerous volatile and non-volatile compounds belonging to the grapes, the fermentation, and aging process. During aging, wines complete their complex composition, and many aromas emerge. Therefore, aging represents a fundamental step to obtaining high-quality wines. Aromas belong directly to the odorless precursor in grapes or to the aging technology used. Analyses have been performed on wines obtained from the cv Carignano subjected to four aging technologies: stainless-steel tank, plastic vat, concrete vat, and oak barrel. GC/FID and GC/MS analysis allowed the identification of 78 significant compounds belonging to eight different chemical classes. Volatile composition in the various containers was assessed at two levels: chemical classes and individual compounds. At 12 months, plastic vats had the highest increase in the total VOC concentration (p < 0.05), followed by concrete and stainless steel. In contrast, oak barrels showed a decrease, although the difference was not statistically significant (p > 0.05). Unsupervised principal component analysis (PCA) demonstrated that the container exerts a more substantial influence at 6 months, while at 12 months, the samples were categorized irrespective of the container. In the loading plot, several esters, acids, lactones, and aldehydes showed negative loadings on PC1 (associated with time), indicating a correlation with the 12-month collection time. Full article

The bacterial microbial community composition during wine fermentation is a key contributor to wine quality and flavor. However, studies on the regulatory effects of different grape varieties and co-fermentation processes on the microbial community structure and their synergistic mechanisms remain limited. In this study, Cabernet Sauvignon (CS) was subjected to single-variety fermentation and used as the base wine for co-fermentation with three other grape varieties—Marselan (CSMN), Merlot (CSMT), and Cabernet Gernischt (CSCG)—to systematically compare the differences in the microbial community composition and their effects on the production of metabolic compounds. The results showed that, compared with single-variety fermentation, co-fermentation significantly increased the α-diversity of microbial communities (the Shannon index increased) and exhibited significant differences in β-diversity (PERMANOVA analysis, R² = 0.421, p < 0.001). A neutral model analysis indicated that co-fermentation had a significant impact on microbial community assembly mechanisms, with the contribution of neutral processes to community assembly increasing from 45.5% (in the CSCG process) to 62.3% (in the CSMT process). A microbial co-occurrence network analysis revealed that co-fermentation enhanced the network complexity of microbial communities and strengthened the synergistic interactions between microbial taxa. A metabolic compound analysis revealed that co-fermentation significantly enhanced the production of key aroma compounds, resulting in increased concentrations of isoamyl acetate, ethyl hexanoate, linalool, and geraniol. These findings highlight the differences in microbial communities and their synergistic mechanisms among co-fermented grape varieties, providing theoretical guidance and practical insights for optimizing co-fermentation processes and improving wine quality. Full article

Wine jelly is regarded as a delicacy in many countries and is commonly utilized in grande cuisine. Recently, its popularity has increased among consumers due to its dietary properties and the presence of health-promoting compounds such as antioxidants. Its natural origin and the ability to reflect local traditions and consumer preferences further enhance its appeal. This study aimed to compare the compositional and sensory characteristics of wine jellies prepared using three different gelling agents and four aromatic grape varieties, with the goal of preserving varietal aroma in the final products. White wines from Pálava and Moravian Muscat and red wines from Agni and Rosa were used. The selected gelling agents were agar, vegan gelatin, and traditional gelatin. Basic analytical parameters were assessed in both the wines and the resulting jellies. Sensory evaluation was conducted by trained panelists, assessing consistency, appearance (clarity), taste, and bouquet. Confectionery-grade jelly from red wines demonstrated the best consistency, while gelatin jellies from white wines showed superior clarity. Due to a preference for sweeter flavors, jellies from red wines were favored across all variants. The strongest varietal bouquet was observed in Moravian Muscat samples, irrespective of the gelling agent used. The optimal choice of gelling agent depends on the target quality attributes. Gelatin is preferred for firmness and clarity, while vegan gelatin is ideal for preserving aroma and achieving a balanced sensory profile. Full article

The wine industry aims to reduce pesticide use by utilizing disease-resistant grape varieties, although their oenological potential remains underexplored. This study aimed to evaluate their oenological potential compared to traditional ones. Musts from resistant (Souvignier Gris, Sauvignac, Voltis, and Floreal) and traditional (Chardonnay, Sauvignon Blanc, and Viognier) varieties were fermented at laboratory scale with online CO₂ monitoring, and two yeasts were used to study varietal responses to yeast impact. Wines were analyzed for metabolites from central carbon metabolism, aromas (varietal thiols, ethyl esters, acetate esters, and higher alcohols), and phenolic compounds (hydroxybenzoic acids, hydroxycinnamic acids, flavan-3-ols, and flavonols) using (U)HPLC methods. Principal component analysis (PCA) of all variables revealed Souvignier Gris grouped with a Sauvignon Blanc sample, partially due to varietal thiols. PCA of aromas (PC1: 37.7%, PC2: 17.8%) showed that Souvignier Gris and Sauvignac exhibited similar behavior to Sauvignon Blanc. The heat map of 19 phenolics showed Sauvignac and Sauvignon Blanc clustered, with lower phenolic abundance. This preliminary work contributes to a detailed characterization of the oenological potential of these new varieties and constitutes an essential step in identifying which traditional and well-known varieties they resemble. This will then enable the recommendation of cellar itineraries adapted to their profile. Full article

Indigenous grape varieties from the Hrvatska Istra subregion (Croatia) represent a significant proportion of regional wine production. In this study, the potential of six indigenous varieties—Malvazija istarska, Garganja, Duranija, Surina, Hrvatica, and Teran—for the traditional method for the production of sparkling wines was evaluated. Several of these varieties are currently underutilized or neglected in contemporary viticulture. A total of 85 volatile aroma compounds, including acids, alcohols, esters, C13-norisoprenoids, and terpenes, were identified and quantified using SPME-Arrow-GC/MS. Sensory evaluation was conducted using a structured nine-point hedonic scale. Among the compounds identified, C13-norisoprenoids (notably β-damascenone, TPB, and TDN) and esters (including ethyl 3-methylbutanoate, ethyl butanoate, and ethyl hexanoate) were found to contribute most significantly to the overall aromatic profile of the sparkling wines. Sensory profiles varied distinctly among the varieties. Some varieties demonstrated pronounced aromatic and structural characteristics, making them suitable for monovarietal sparkling wine production, while others exhibited complementary sensory properties more appropriate for cuvées. This study represents the first comprehensive chemical and descriptive sensory profiling of sparkling wines produced from these Istrian indigenous grape varieties. These findings aim to support their valorization and integration into the broader spectrum of sparkling wine production, thereby enhancing their recognition and market potential. Full article

Grape liqueurs are a promising approach to diversifying fruit-derived beverages and adding value to local raw materials. This study evaluated the impact of cereal alcohol (A) and white cachaça (C) on the physicochemical composition, anthocyanin profile, and sensory attributes of liqueurs made with the Brazilian cultivar BRS Carmem. Both products met regulatory requirements (alcohol content > 15% v/v and sugar > 100 g⋅L⁻¹). The alcoholic base significantly influenced most physicochemical parameters but not the anthocyanin profile. The liqueur with A resulted in higher extraction of organic acids (0.39 vs. 0.33 g tartaric acid⋅100 g⁻¹) and phenolic compounds (607.45 vs. 457.64 mg gallic acid⋅100 g⁻¹). HPLC-DAD-ESI-MS/MS analysis showed a predominance of diglycosylated anthocyanins (98%), with concentrations of 420.04 mg⋅L⁻¹ (A) and 456.44 mg⋅L⁻¹ (C). Both liqueurs were well accepted (overall impression: A = 7.1, C = 7.2) with good purchase intent (A = 63.03% and C = 56.75%). Significant differences were observed for appearance and color (preferred in A) and aroma (preferred in C). These attributes correlated strongly with the overall impression, but flavor and alcohol content were the key factors influencing purchase decisions. The findings demonstrate that the choice of alcoholic base affects the composition and sensory acceptance of grape liqueurs, highlighting their importance to enhance the product’s quality. Full article

The different impact and interaction of pulsed electric field (PEF) treatment and sulfite addition on the color, phenolic compounds, volatile profile, and sensory properties of a Primitivo wine were studied at bottling and after six months of storage. The results show that PEF treatment, promoting the electroporation of grape skin cells and the permeability of cell membranes, accelerated the extraction of anthocyanins and polyphenols only in the initial phase of maceration. After six months in bottles, wines treated only with PEF show lower levels of hydroxycinnamic acids and flavonols, but a significant increase in procyanidins B2, which are important for structure and color stability and a richer flavor profile, with higher concentrations of fruity esters and higher alcohols. The use of SO₂ improves anthocyanin stabilization and facilitates the extraction of polyphenols. The wines from the PEF + SO₂ combination maintain greater aromatic freshness, limiting the formation of oxidative compounds. Wines made from SO₂ have a more balanced profile, with cherry, plum, and licorice aromas, although the combined PEF + SO₂ treatment better preserves fresh fruit aromas, reducing the perception of dried fruits and herbaceous notes. Full article

The bagging technique is a traditional preharvest practice used in Vinalopó Bagged Table Grape production to improve fruit quality and protect clusters from environmental stress. However, its influence on grape volatile composition remains underexplored. This study analyzed the volatile profile of three grape varieties (‘Dominga’, ‘Aledo’, and ‘Doña María’) by comparing bagged and non-bagged clusters to assess the effect of bagging on aromatic compounds. Volatiles were extracted using headspace solid-phase microextraction (HS-SPME) and analyzed by gas chromatography–mass spectrometry (GC–MS). A total of 35 volatile compounds were identified and quantified, mainly aldehydes, terpenes, and alcohols. The highest concentration was found in non-bagged ‘Dominga’ grapes (57.17 mg kg⁻¹), and the lowest in bagged ‘Doña María’ grapes (16.36 mg kg⁻¹). Although total volatile content did not differ significantly between treatments, differences were observed in the relative abundance of chemical families. Bagged grapes showed higher proportions of aldehydes, such as hexanal and (E)-2-hexenal, contributing to green, fresh aromas, while non-bagged grapes exhibited more alcohols and esters, linked to fruity and overripe notes. This study offers new insights into the role of preharvest bagging in shaping grape volatile composition, contributing to a better understanding of its impact on fruit aroma and quality. Full article

The effects of spontaneous fermentation and the inoculation of grape must with a flocculant yeast starter culture, together with the supplementation of must with a commercial organic nitrogen compound (ONC), were analyzed. The microbiome during fermentation was tracked, and volatile compounds in the resulting wines were identified and quantified using gas chromatography and mass spectrometry (GC-MS). Volatile compound concentrations were then subjected to statistical analysis. No significant differences in pH, titratable and volatile acidity, and ethanol and lactic acid were observed among the four wines analyzed. However, the musts supplemented with the ONC slightly increased the fermentation rate of the flocculant yeast, and, also, this additive reduced the volume of lees in the spontaneous fermentation and flocculant yeast by 1.2% and 0.6%, respectively. The concentrations of 11 major and 28 minor volatiles were significantly influenced (p-value ≤ 0.05) by the inoculation strategy, while 8 major and 28 minor volatiles were affected by ONC supplementation. This supplementation significantly decreased the Odor Activity Values and, consequently, the values of the odorant series established in wines from spontaneous fermentation. On the contrary, those from flocculant yeast showed a significant increase in all the odorant series except for the waxy series, leading to a more balanced aroma profile. Additionally, lower scores were recorded for the green, creamy, citrus, chemical, and honey series compared to wines from spontaneous fermentation. Overall, the commercial ONC extract contributed to a content increase in volatiles that provided desirable aromatic notes to the wines made with flocculant yeast, although the organoleptic evaluation showed no significant statistical differences in the attributes evaluated at the 95% confidence level. Full article

While studies on the co-fermentation of fruits and grapes are reported in the literature, blends of wine and fruit wine have never been investigated before. We characterised a blend (80:20 v/v) of Trebbiano Abruzzese white wine, organic kiwifruit wine, and the sparkling beverage obtained by its successive refermentation in a bottle. A persimmon/kiwifruit wine (50:50 v/v), after and before alcoholic fermentation, was also analysed. The buffer capacity, redox potential, concentration of selected polyphenols, total polyphenol content, antioxidant activity, and volatile profile were evaluated. The addition of kiwifruit wine to Trebbiano Abruzzese confers, to the final beverage, an appreciable improvement in terms of antioxidant activity, related to the content of polyphenols and ascorbic acid, which is substantially preserved in the sparkling product. Appreciable differences in the aroma of the blend compared to pure wine are mainly associated with the increased content of norisoprenoids, terpenes, methyl esters, and sulphur compounds, arising from the kiwifruit wine. The innovative beverages here proposed exhibit distinctive compositional and sensorial attributes that can be appreciated by consumers. Full article

Non-Saccharomyces yeasts have the potential to ameliorate wine ethanol levels, but such fit-for-purpose yeast strains are still lacking. Seventy-one indigenous non-Saccharomyces yeasts isolated from spontaneous fermentations of four wine regions in China (Ningxia, Xinjiang, Gansu, and Shaanxi) were screened for ethanol formation and were characterized for major metabolite profiles in synthetic grape juice fermentation to obtain non-Saccharomyces yeasts with low ethanol yields. Four Hanseniaspora strains with less volatile acidity production were primarily selected, and their ethanol yield was reduced by 22–32% compared to S. cerevisiae. These strains were further evaluated for oenological properties, namely ethanol and temperature tolerance, H₂S production, and killer activities against S. cerevisiae. Strain HuC-3-2 was then subjected to Atmospheric Room Temperature Plasma (ARTP) mutagenesis, and a mutant (HuC32-2-72) with rapid growth and optimized ethanol-reducing capability was obtained. The best-performing strains were further characterized in sequential fermentations with S. cerevisiae in Merlot juice, and resulted in a 1.4% v/v decrease in ethanol yield. Comprehensive analysis of yeast populations and the production of key metabolites highlighted important carbon sinks, as well as glycerol formation, partially accounting for the ethanol reduction. In addition to ethanol amelioration, the Hanseniaspora strains also led to alterations in many metabolites, including volatile compounds and some organic acids, which can further modulate wine aroma and flavor. Full article