Search Results (177)

Petit Manseng is a variety of Vitis vinifera gaining popularity in Virginia, USA because it consistently produces high quality grapes under variable growing conditions. However, its high sugar and acid levels complicate dry wine production. The goal of this study was to characterize Petit Manseng ripening kinetics from veraison to harvest to identify optimal harvest timing for producing dry white wines, using Chardonnay as a comparator because of its popularity in Virginia, well-known ripening kinetics, and ability to produce high quality dry white wines. A total of 74 samples of Petit Manseng and Chardonnay grapes were collected from five commercial sites over 2 years and evaluated for berry weight, pH, titratable acidity (TA), malic acid, total soluble solids (TSS), glucose, and fructose, with ripening kinetics modeled using segmented regressions. Results indicated that harvest timing and grape variety were the primary factors influencing ripening kinetics. In contrast, growing location and vintage had limited impact. In Chardonnay grapes, TA declined from 21 to 7.1 g/L and TSS increased from 6.1 to 19.5 g/L. In Petit Manseng, TA declined from 25 to 10.8 g/L and TSS increased from 8.0 to 23.6 g/L. Acid depletion plateaued ~2 weeks after sugar accumulation plateaued in Petit Manseng grapes, though the plateaus were similar in Chardonnay grapes. Linear discriminant analysis (LDA) completely separated grapes based on pH or TA vs. sugars, but not malic acid vs. sugars, suggesting that tartaric acid is driving acidity differences between cultivars. These data indicate that regardless of when grapes are harvested, winemakers may need to employ targeted acid management strategies with Petit Manseng because of its ripening kinetics. Full article

Grape pomace (GP), the main by-product of the wine industry, represents a valuable source of bioactive metabolites with significant potential for valorization in the context of sustainable bioresource management. This study systematically characterizes the fatty acid methyl ester (FAME) profile, total phenolic content (TPC), total flavonoid content (TFC), and antioxidant activities (DPPH, ABTS, ORAC) of GP derived from seven grape varieties across three consecutive vintages (2022–2024). White GP, particularly Verdelho and Sercial, exhibited a superior lipid quality with high concentrations of methyl linoleate (up to 1997 mg/100 g DW) and methyl oleate (up to 1294 mg/100 g DW), low atherogenic (AI < 0.05) and thrombogenic indices (TI ≤ 0.13), and elevated PUFA/SFA ratios (≥8.2). In contrast, red GP, especially from Complexa and Tinta Negra, demonstrated the highest antioxidant potential, with TPC values up to 6687 mgGAE/100 g DW, TFC up to 4624 mgQE/100 g DW, and antioxidant activities reaching 5399 mgTE/100 g (DPPH) and 7219 mgTE/100 g (ABTS). Multivariate statistical analyses (PCA, PLS-DA, HCA) revealed distinct varietal and vintage-dependent clustering and identified key discriminant fatty acids, including linolenic acid (C18:3), lauric acid (C12:0), and arachidic acid (C20:0). These findings underscore the compositional diversity and functional potential of GP, reinforcing its suitability for applications in functional foods, nutraceuticals, and cosmetics, in alignment with circular economy principles. Full article

This study investigated young white wines produced during the 2021 and 2022 vintages from Pedro Ximénez grapes cultivated in three different terroirs within a high-quality production zone. The general oenological parameters were significantly influenced by vintage and terroir (p ≤ 0.001), with ethanol and reducing sugars specifically affected by the terroir and its interaction with the vintage. Multivariate analysis of major and minor volatile compounds enabled the characterization of terroir-specific volatile profiles. However, principal component analysis (PCA) grouped samples by vintage rather than terroir. Ethyl esters of medium- and long-chain fatty acids and certain acetates of higher alcohols were the most discriminant volatiles and were proposed as key compounds for differentiating wines by terroir and vintage. These findings underscore the influence of the terroir on the volatilome and support its relevance in defining wine typicity and quality. Full article

Saccharomyces cerevisiae plays a fundamental role in winemaking, not only driving alcoholic fermentation but also producing secondary metabolites that contribute to the organoleptic properties of wine. To ensure consistent quality and process efficiency, wineries commonly employ selected starter strains. Accordingly, the ability to control strain purity and traceability is of critical importance. Currently, the inter-delta PCR method is widely used for the strain-specific genotyping of S. cerevisiae. However, its resolution diminishes when analyzing genetically similar strains, such as those isolated from related grape types or during genotyping of large yeast collections. To address this limitation, we developed a novel strategy that integrates computational and experimental approaches to identify highly specific allelic variants (single nucleotide polymorphisms, SNPs) within the S. cerevisiae genome. Comparative genomic analysis of twenty-eight different strains led to the identification of multiple strain-specific SNPs. From these, nine SNPs spanning five strains were selected and validated through targeted PCR assays. These assays confirmed the feasibility of using SNPs as reliable genetic markers for strain discrimination and traceability. Overall, our findings demonstrate that this SNP-based approach, implemented via multiplex allele-specific (AS) PCR assays, offers a rapid, cost-effective, and highly discriminatory alternative to current genotyping methods, particularly for differentiating closely related strains. Full article

Wine organic acids influence their overall quality. This study examines the variability of major acids (tartaric, malic, lactic, citric, acetic, and gluconic) and minor phenolic acids (gallic, protocatechuic, syringic, caftaric, caffeic, cutaric, coumaric, and 2-S-glutathionylcaftaric) in varietal red wines produced from predominantly autochthonous grape cultivars of the Canary Islands. Two hundred and five monovarietal red wine samples were analyzed to assess how the organic acid profiles differed depending on the grape cultivars employed in their production, island of provenance, denomination of origin, and aging, supporting relationships between both genetic and environmental factors. High-performance liquid chromatography and enzymatic methods were used for determining minor and major organic acids, respectively. Many significant differences between grape cultivars, geographical origin, and aging were observed, reflecting the complexity of the composition of the organic acids in red wine and its relationship with viticultural factors. Linear discriminant analysis achieved classification accuracies up to 88.3% by cultivar and 83.4% by island. Correlation and multivariate analyses helped identify compositional patterns and key discriminant acids. This study advances the comprehension of major and minor acid composition and equilibria in red wines and may support future research on quality parameters and regional typicity. Full article

Climate change (CC) is a major threat to agriculture, the sector that supports the territorial economy in the Pays Haut Languedoc et Vignoble (PHLV) region (south France). In this region, farms have been facing the negative effects of CC for several decades. The implementation of agriculture adaptation policies requires a coherent and integrated tool that mobilizes approaches for territorial development, vulnerability assessments, and feasibility. The purpose of this research is to provide a multi-criteria assessment of farm vulnerability to CC in the PHLV region. An index of farm vulnerability was developed based on the classic model of vulnerability, which is the product of exposure and sensitivity divided by adaptive capacity. This assessment was conducted at the farm level, by combining biophysical variables (such as soil type and irrigation) and socioeconomic variables (such as agricultural experience and crop insurance), selected based on a literature review and interviews with local stakeholders and local experts. To solve the weighting problem, we differentiated between a “calculated vulnerability”, without any specific weighting of the vulnerability variables, and a “declared vulnerability” that integrates the scores assigned to the importance of each variable for each farmer surveyed, based on their awareness. Afterward, a discriminant analysis was used to identify the factors that determine the vulnerability classes. Our results show that (i) the majority of the surveyed farms have a relatively high vulnerability index, but wine farms and cereal farms are the most vulnerable; (ii) for all farms the “declared vulnerability” is lower than the “calculated vulnerability”, showing that farmers underestimate their vulnerability; (iii) there is an interesting link between the low level of vulnerability and the adaptation efforts already made over the past ten years by certain farms that have changed or introduced crops and improved their agricultural practices. Full article

This study investigated the correlation between five primary volatile phenols (VPs) and their glycosides in smoke-exposed and non-smoke-exposed Pinot noir wines to assess and identify potential markers for smoke taint. The results showed that all putative VP-glycosides in smoke-exposed wines were higher than in non-smoke-exposed wines, with a fold change ranging from 2.11 to 31.88 for the top fifteen differentiations. VP-glycosides showed strong positive correlations among themselves, with correlation coefficients of 0.94 for hexose-guaiacol vs. pentose (P)-hexose (H)-cresol and 0.92 for syringyl-β-D-glucopyranoside vs. H-P-4-methylguaiacol. VP-glycosides also showed relatively high correlations with free and strong acid-hydrolyzed VPs. The correlation coefficient between H-P-guaiacol and free-form guaiacol is 0.71, and between H-P-guaiacol and total guaiacol is 0.78. The strong correlation suggests that these compounds are interconnected and regulated by the severity of smoke exposure. Multivariate analysis effectively differentiated smoke-exposed wines from non-smoke-exposed ones. However, more research is needed to fill the gaps in understanding smoke-derived compounds. Full article

This study addresses the contamination of sparkling wines by 2,4,6-trichloroanisole (TCA), a compound responsible for the “cork taint” or musty aroma in wines. Currently, its detection requires complex and expensive techniques such as chromatography and sensory panels. An innovative method is proposed using an electronic nose (e-nose) prototype, offering objective, non-destructive, and cost-effective analysis. The e-nose’s ability to detect TCA at various concentrations was evaluated in sparkling wines from different batches and a spiked wine sample. The results analyzed using Principal Component Analysis (PCA) successfully differentiated the samples. An Artificial Neural Network Discriminant Analysis (ANNDA) classified wines based on whether their TCA concentration exceeded 2 ng/L, achieving 88% accuracy. A quantitative predictive model using Partial Least Squares (PLS) analysis yielded an R² of 0.84 across wines and 0.95 in a single sample. These advances highlight the potential of the e-nose to improve quality control in the wine industry. Full article

This study aimed to investigate the effects of post-fermentation freezing treatment on the flavor characteristics of Beibinghong ice wine. Physicochemical indices, organic acids, volatile compound content, odor activity values (OAVs), and sensory attributes of ice wines subjected to different treatments were systematically analyzed using high-performance liquid chromatography (HPLC), headspace gas chromatography–ion mobility spectrometry (HS-GC-IMS), sensory evaluation, and orthogonal partial least squares discriminant analysis (OPLS-DA). The results demonstrated significant differences in fundamental physicochemical indices between freezing-treated and control samples. The freezing treatment significantly reduced total acid, total sugar, and tannin content, thereby alleviating cloyingly sweet and pungent taste sensations and achieving a more harmonious and balanced flavor profile. Concurrently, alterations in the levels of esters, alcohols, and other volatile compounds were observed, with 10% alcohol-by-volume (ABV) freezing-treated samples exhibiting optimal performance in aromatic complexity (featuring fruity and honey notes) and taste balance. Sensory evaluation further confirmed that freezing treatment enhanced the delicacy and complexity of ice wine aromas. This study demonstrates that post-fermentation freezing treatment effectively optimizes the flavor profile of ice wine, providing a theoretical foundation for refining ice wine production processes. Full article

Fourteen non-colored flavonoids, including flavanols (catequine and epicatequine) and flavonols (myricetin, quercetin, and isorhamnetin and their glucoside/glucuronide derivatives) were investigated in over two hundred monovarietal red wines from the Canary Islands, as a continuation of a previous study available in this journal. This is the first comprehensive study on non-colored flavonoids in monovarietal Canary wines, highlighting their potential as chemical fingerprints for wine characterization. Flavanal and flavanol concentrations were similar to values reported in other regions. Concentrations of these flavonoids significantly varied by grape cultivar, denomination of origin (DO), island, and aging. International grape cultivars generally showed higher non-colored flavonoid concentrations than autochthonous cultivars. Strong correlations were observed among flavonols of the same chemical groups, as well as between flavonols and anthocyanins, indicating a shared biosynthesis pathway in grapes and equilibria in wine. Principal component analysis revealed relationships among the individual flavonoids. Lineal discriminant analysis (LDA) resulted in high percentages of correct classification by cultivar, DO, precedence island, and aging. The classification accuracy achieved through LDA, except for aging, notably improved compared to the previous study that examined only visible flavonoids, underscoring the importance and effectiveness of non-colored flavonoid profiling. Full article

Electronic noses (E-noses) have become powerful tools for the rapid and cost-effective differentiation of wines, providing valuable information for the comprehensive evaluation of aroma patterns. However, they need to be trained and validated using classical analytical techniques, such as gas chromatography coupled with mass spectrometry, which accurately identify the volatile compounds in wine. In this study, five low-ethanol wines with distinctive sensory profiles—produced using Saccharomyces and non-Saccharomyces yeasts and tailored to modern consumer preferences—were analyzed to validate the E-nose. A total of 57 volatile compounds were quantified, 27 of which had an Odor Activity Value (OAV) over 0.2. The content in volatiles, grouped into 11 odorant series according to their odor descriptors, along with the data provided by 12 E-nose sensors, underwent advanced statistical treatments to identify relationships between both data matrices. Partial least squares discriminant analysis (PLS-DA) applied to the data from the 12 E-nose sensors revealed well-defined clustering patterns and produced a model that explained approximately 92% of the observed variability. In addition, a principal component regression (PCR) model was developed to assess the ability of the E-nose to non-destructively predict odorant series in wine. The synergy between the volatile compound profiles and the pattern recognition capability of the E-nose, as captured by PLS-DA, enables a detailed characterization of wine aromas. In addition, predictive models that integrate data from gas chromatography, flame ionization detection, and mass spectrometry (GC-FID/GC-MSD) with the electronic nose demonstrating a promising approach for a rapid and accurate odor series prediction, thereby increasing the efficiency of wine aroma analysis. Full article

Demonstrating the authenticity and traceability of quality wines based on parameters that reflect their composition and provenance contributes to protecting wine authenticity and to increasing consumer confidence in moderate wine consumption, which is associated with numerous health-promoting properties. A wine’s phenolic fingerprint is increasingly used to assess its authenticity, even though wine phenolic composition is influenced by genetic and environmental factors, as well as vineyard management and enological practices, and storage conditions. This study presents a comprehensive analysis of the bioactive characteristics (total polyphenols—TPs, total flavonoids—TFs, antioxidant activity—AA, and total anthocyanins—TAs) by spectrophotometric analysis and phenolic compound profile (by UHPLC-HRMS analysis) of 19 white and 21 red wines with a Protected Designation of Origin (PDO) from four vineyards located in the wine-growing region of Oltenia, Romania. Multivariate statistical analysis, specifically principal component analysis and heat map analysis, applied to analytical data, enables the discrimination of wines based on grape variety and terroir, and across four consecutive vintages (2019–2022). The phenolic profiles of the wines obtained under standardized winemaking conditions depend on the climatic data specific to each harvest year (temperature, precipitation, duration of sun exposure during grape berry phenological stages, and ripening). The phenolic biomarkers of red wines, such as epicatechin, catechin, gallic, caffeic, t-ferulic acids, t-resveratrol and hesperidin, represent specific biomarkers of warmer and sunnier harvest years with lower precipitation, as observed in the 2021 harvest year. Additionally, our results contribute to the identification of specific phenolic biomarkers for geographical and varietal discrimination, as well as to the promotion of high-quality wines produced in a renowned wine-growing region of Romania. Full article

In response to climate change, there is a decoupling between technological and phenolic maturity in vineyards. This study investigates the application of elicitors, specifically methyl jasmonate (MeJA) and grape pomace extract (GPE), administered at veraison and one week later over two consecutive seasons. Samples collected at 21 and 23 °Brix reveal delayed ripening for both treatments. MeJA significantly impacted extractable anthocyanins, the seed maturity index, and total anthocyanins, with optimal results at 23 °Brix compared to the control. GPE elevates proanthocyanin content at the same maturity level. Although the effects in wines are less pronounced, the MeJA-treated grapes harvested at 23 °Brix produce wines with reduced alcohol content, enhanced color intensity, and increased EGC-ext. Finally, a discriminant analysis indicated that the MeJA-treated grapes at 23 °Brix differed most significantly from the control, with seasonal variations playing a crucial role. Thus, MeJA 23 °Brix treatment demonstrated the most promising results, warranting further exploration with complementary winery technology to maximize its potential in vinification. Full article

Maratheftiko (Vitis vinifera sp.) is a prestigious grape variety native to Cyprus, but wines originating from this variety have not been examined with respect to the effect of aging on major quality determinants, such as their aromatic and polyphenolic composition. Following a previous work on the impact of prefermentation treatments on Maratheftiko wines, this work was carried out with the objective of studying the effect of barrel aging on Maratheftiko wines, produced on industrial scale with different prefermentation technologies. These technologies includes combinations of the saigneé process, cold maceration, and enzyme and tannin addition. The influence of these treatments was illustrated by determining the pigment, non-pigment polyphenols, and volatiles from two consecutive harvests. The predominant non-pigment polyphenol for the 2021 vintage was quercetin 3-O-glucuronide, accompanied by a ferulate derivative, but for the 2022 vintage, quercetin 3-O-glucuronide predominated along with caftaric acid. The principal anthocyanin in all samples examined was malvidin 3-O-glucoside, followed by its p-coumarate derivative. The primary aromatic substances determined were isoamyl alcohol, followed by 2-phenylethanol. Principal component analysis showed that there was discrimination based on prefermentation treatments; however, distinction was more pronounced based on vintage. This investigation provided heretofore unreported data and revealed novel insights into the effect of aging on Maratheftiko wines. Full article

Food safety and quality awareness have reached significant relevance as consumers are more interested in authentic foods and drinks with specific organoleptic values. Among foodstuffs, grape products can be contaminated by Ochratoxin A (OTA), a mycotoxin that can occur in red grape after infection with Aspergillus carbonarius. The high affinity of grape pomace with OTA makes its use advantageous as an adsorbing/decontaminating material whether the pomace is fresh, has undergone pressing, or has undergone a stabilizing process. The effects of different grape repassage treatments on wine metabolic profiles were studied by ¹H NMR spectroscopy coupled with metabolomics. The relative quantification of discriminating metabolites for activated-carbon-treated samples revealed higher levels of ethyl acetate and succinate than for the grape-pomace-repassed wine samples. On the contrary, the latter exhibited a relatively high content of glycerol, lactate, tartaric, isobutanol, isopentanol, and polyphenols. Although a specific decrease in aromatic compounds such as gallic acid, tyrosine, and tyrosol was also observed compared with the controls, for the pomace-based processes, the activated carbon treatment led to a marked general impoverishment of the metabolomic profiles, with a reduction in organic acids and glycerol. The repassage of wine over the grape pomace did not significantly affect the quality attributes of the wine, offering an alternative natural adsorbing/decontaminating material for the removal of OTA. Full article