Search Results (12)

A new negative-strand RNA virus was identified in grapevines from a 38-year-old ‘Chardonnay’ block in Idaho through high-throughput sequencing (HTS) of total RNA. This virus was tentatively named grapevine-associated cogu-like Idaho virus (GaCLIdV). GaCLIdV has three negative-sense, single-stranded RNA genome segments of ca. 7 kb, 1.9 kb, and 1.3 kb, encoding L protein (RNA-dependent RNA polymerase, RdRP), a movement protein (MP), and a nucleocapsid protein (NC), respectively, identified based on pair-wise comparisons with other cogu- and cogu-like viruses. In phylogenetic analysis based on the RdRP, GaCLIdV grouped within the family Phenuiviridae and was placed in a lineage of plant-infecting phenuiviruses as a sister clade of the genus Laulavirus, clustering most closely with switchgrass phenui-like virus 1 (SgPLV-1) and more distantly related to grapevine-associated cogu-like viruses from the Laulavirus and Coguvirus clades. Both GaCLIdV and SgPhLV-1 are proposed to form a new genus, Switvirus, within the family Phenuiviridae. The presence of GaCLIdV in the original ‘Chardonnay’ samples was confirmed by RT-PCR amplification and Sanger sequencing. This new virus was found in five wine grape cultivars and in six vineyards sampled in Idaho and in Oregon during the 2020–2024 seasons. GaCLIdV may have contributed to the decline observed in the old ‘Chardonnay’ block, although the role of the virus in symptom development awaits further investigation. Full article

This study investigated specific winemaking procedures that could increase fermentation esters and volatile thiols in Chardonnay wine during fermentation. These compounds together are known to cause tropical fruit aromas. Two levels of pre-fermentative skin contact (10 °C for 18 h) (yes/no), two levels of β-lyase addition (40 μL/L) (yes/no), and three levels of fermentation gradient temperature, FG0 (constant 13 °C), FG1 (started at 20 °C and after 96 h dropped to 13 °C), and FG2 (started at 20 °C and after ~11.5 °Brix dropped to 13 °C), were evaluated using laboratory-scale ferments in a full factorial design. Esters and the volatile thiols, 3-sulfanylhexan-1-ol (3SH), 3-sulfanylhexyl acetate (3SHA), and 4-methyl-4-sulfanylpentan-2-one (4MSP), were quantified using gas and liquid chromatography methods, respectively. The combination of skin contact and FG1 or FG2 resulted in the greatest levels of esters and thiols in Chardonnay wine. The fermentation gradient was shown to be efficient in reducing volatile compounds normally lost due to evaporation during fermentation. With these different processing techniques, it will be possible for winemakers to achieve different wine qualities depending on their chosen wine style. Full article

It has been reported that polysaccharides in wine can interact with tannins and other wine components and modify the sensory properties of the wine. Unfortunately, the contribution of polysaccharides to wine quality is poorly understood, mainly due to their complicated structure and varied composition. In addition, the composition and molecular structure of polysaccharides in different wines can vary greatly. In this study, the polysaccharides were isolated from pinot noir wine, then separated into high-molecular-weight (PNWP-H) and low-molecular-weight (PNWP-L) fractions using membrane-based ultrafiltration. Each polysaccharide fraction was further studied using size exclusion chromatography, UV–Vis, FT-IR, matrix-assisted laser desorption/ionization–high-resolution mass spectrometry, and gas chromatography-mass spectrometry (GC-MS). The results showed that PNWP-L and PNWP-H had different chemical properties and compositions. The FT-IR analysis showed that PNWPs were acidic polysaccharides with α- and β-type glycosidic linkages. PNWP-L and PNWP-H had different α- and β-type glycosidic linkage structures. FT-IR showed stronger antisymmetric and symmetric stretching vibrations of carboxylate anions of uronic acids in PNWP-L, suggesting more uronic acid in PNWP-L. The size exclusion chromatography results showed that over 72% of the PNWP-H fraction had molecular sizes from 25 kDa to 670 kDa. Only a small percentage of smaller molecular polysaccharides was found in the PNWP-H fraction. In comparison, all of the polysaccharides in the PNWP-L fraction were below 25 KDa, with a majority distributed approximately 6 kDa (95.1%). GC-MS sugar composition analysis showed that PNWP-L was mainly composed of galacturonic acid, rhamnose, galactose, and arabinose, while PNWP-H was mainly composed of mannose, arabinose, and galactose. The molecular size distribution and sugar composition analysis suggested that the PNWP-L primarily consisted of rhamnogalacturonans and polysaccharides rich in arabinose and galactose (PRAG). In comparison, PNWP-H were mostly mannoproteins and polysaccharides rich in arabinose and galactose (PRAG). Further research is needed to understand the impacts of these fractions on wine organoleptic properties. Full article

Grapevine red blotch disease (GRBD) has negative effects on grape development and impacts berry ripening. Abscisic acid (ABA) is a plant growth regulator involved in the initiation of berry ripening. Exogenous abscisic acid application was compared to an unsprayed control on GRBD-positive Pinot noir vines during two vintages, and the total monomeric anthocyanin, total phenolics, phenolic composition, and volatile profile were measured in wines. In addition, untargeted metabolites were profiled using high-resolution LC-MS/MS. Results showed that the wine composition varied by vintage year and was not consistent with ABA application. Wines from the ABA treatment had a lower total anthocyanin and total phenolic content in one year. The untargeted high-resolution LC-MS/MS analysis showed a higher abundance of phenolic compounds in ABA wines in 2019, but lower in 2018. The wine volatile compounds of ABA treatments varied by vintage. There were higher levels of free β-damascenone, β-ionone, nerol, and several fermentation-derived esters, acids, and alcohols in ABA wines, but these were not observed in 2019. Lower 3-isobutyl-2-methoxypyrazine (IBMP) was also observed in wines with ABA treatment in 2019. The results demonstrated that ABA application to the fruit zones did not consistently mitigate the adverse impacts of GRBD on Pinot noir wines. Full article

Real-time process metrics are standard for the majority of fermentation-based industries but have not been widely adopted by the wine industry. In this study, replicate fermentations were conducted with temperature as the main process parameter and assessed via in-line Oxidation Reduction Potential (ORP) probes and at-line profiling of phenolics compounds by UV-Vis spectroscopy. The California and Oregon vineyards used in this study displayed consistent vinification outcomes over five vintages and are representative of sites producing faster- and slower-fermenting musts. The selected sites have been previously characterized by fermentation kinetics, elemental profile, phenolics, and sensory analysis. ORP probes were integrated into individual fermentors to record how ORP changed throughout the fermentation process. The ORP profiles generally followed expected trends with deviations revealing previously undetectable process differences between sites and replicates. Site-specific differences were also observed in phenolic and anthocyanin extraction. Elemental composition was also analyzed for each vineyard, revealing distinctive profiles that correlated with the fermentation kinetics and may influence the redox status of these wines. The rapid ORP responses observed related to winemaking decisions and yeast activity suggest ORP is a useful process parameter that should be tracked in addition to Brix, temperature, and phenolics extraction for monitoring fermentations. Full article

Fruitiness is a highly desirable aroma quality in white wines. This study aimed to investigate the fruitiness aroma perception of white wines using a rapid sensory method and to compare the sensory maps obtained from wine experts and trained consumers. A polarized projective mapping (PPM) method was adapted by using fruit standards as fixed poles. Twenty-one white wines were selected for this study. Ten wine experts and twelve trained consumers participated in the adapted PPM followed by ultra-flash profiling (UFP). While experts and trained consumers used different poles to characterize the Pinot Gris and Viogniers, both panels used the stone fruit pole for the Chardonnays. UFP revealed that the Pinot Gris and Viognier samples presented fruity and floral aromas and most Chardonnay wines presented non-fruity aromas. The white wines investigated presented a wide range of fruity aromas. The use of aroma standards instead of products as poles seems to be a reliable alternative to investigate fruitiness in white wines. This study helped us to understand the predominant aromas of varietal white wines from Oregon and emphasized the importance of adapting sensory methods to investigate fruitiness perception. Full article

Volatile compounds are responsible for driving the aroma of wine. Because of their low perception thresholds, norisoprenoids may play an important role in wine aroma. Studies have shown that β-damascenone may act as an aroma enhancing compound. However, the direct impact on wine aroma is unclear. Our study examined the direct impact of β-ionone and β-damascenone on the aroma sensory perception of Pinot noir wines. Triangle tests were used to determine if assessors could distinguish between wines with varying concentrations of β-ionone and β-damascenone in three different Pinot noir wine matrixes. Descriptive analysis was performed on these treatments, perceived as different in triangle tests. Results show that β-ionone acts as a significant contributor to aromas in Pinot noir wine, as individuals could differentiate both the low and high concentration wines from the control. How β-ionone impacted wine aroma depends on the wine matrix, as different aroma descriptors were affected based on the model wine used, resulting in floral, red berry or dark berry aromas. The effect of β-damascenone on Pinot noir aroma was less clear, as perception seems to be heavily influenced by wine matrix composition. This study contributes to our understanding of the complex chemical causation of fruity aromas in Pinot noir wine. Full article

Substantial environmental impacts and loss of resilience occurs with conventional vineyard designs characterized by monotonous specialized production. Studies support the restoration of green infrastructure (GI) and introduction of other production systems as promising biodiversity design strategies. However, little is known about the degree to which winegrowers are implementing them. We surveyed Willamette valley, Oregon, certified sustainable winegrowers as potential early adopters of innovative biodiversity design strategies. Results revealed growers were implementing up to 11 different types of GI components, providing them with up to 16 different ecosystem services, and six disservices. The GI was implemented at three spatial scales, with growers pursuing a sharing GI design strategy at fine scales, and a sharing and sparing strategy at intermediate and farm-wide scales. Only biodynamic certified farmers had implemented valued additional production systems. Growers can improve the implementation of their biodiversity GI designs by adopting an integrated multi-system whole farm design approach. Key enablers for grower implementation of GI and/or additional production systems included: (1) Grower awareness and value of strategy’s ecosystem services and functions, (2) grower knowledge of their design and management, (3) certifier requirements for GI, (4) availability of land incapable of growing quality grapes, (5) availability of GI backup systems in case of failure, (6) low risk of regional pest outbreaks, (7) premium wine prices, and (8) strong grower environmental and cultural heritage ethics. Further research is required to identify effective ways to advance these enablers among growers, and within certification and government programmes, to improve the implementation of these strategies among growers. Full article

Complications in the analysis of volatile sulfur compounds (VSC) in wine using solid-phase microextraction (SPME) arise from sample variability. Constituents of the wine matrix, including ethanol, affect the volatility and adsorption of sulfur volatiles on SPME fiber coatings (Carboxen- polydimethylsiloxane(PDMS); DVB-Carboxen-PDMS and DVB-PDMS), which can impact sensitivity and accuracy. Here, several common wine sulfur volatiles, including hydrogen sulfide (H₂S), methanethiol (MeSH), dimethyl sulfide (DMS), dimethyl disulfide (DMDS), dimethyl trisulfide (DMTS), diethyl disulfide (DEDS), methyl thioacetate (MeSOAc), and ethyl thioacetate (EtSOAc) are analyzed, using SPME followed by gas chromatography (GC), using a system equipped with a pulsed-flame photometric detection (PFPD) system, at various ethanol concentrations in a synthetic wine matrix. Ethyl methyl sulfide (EMS), diethyl sulfide (DES), methyl isopropyl sulfide (MIS), ethyl isopropyl sulfide (EIS), and diisopropyl disulfide (DIDS) are evaluated as internal standards. The absorption of volatile compounds on the SPME fiber is greatly affected by ethanol. All compounds exhibit a stark decrease in detectability with the addition of ethanol, especially between 0.0 and 0.5% v/v. However, the ratio of interested sulfur compounds to the internal standard becomes more stable when the total alcohol concentration exceeds 2%. EMS was found to best resemble DMS. EIS and DES were found to best resemble DMDS, MeSOAc, and EtSOAc. DIDS was found to best resemble DEDS, DMTS, H₂S, and MeSH. Full article

The analysis of volatile sulfur compounds using headspace solid-phase microextraction (HS-SPME) is heavily influenced by matrix effects. The effects of a wine matrix, both non-volatile and volatile components (other than ethanol) were studied on the analysis of several common sulfur volatiles found in wine, including hydrogen sulfide (H₂S), methanethiol (MeSH), dimethyl sulfide (DMS), dimethyl disulfide (DMDS), dimethyl trisulfide (DMTS), diethyl disulfide (DEDS), methyl thioacetate (MeSOAc), and ethyl thioacetate (EtSOAc). Varying levels of devolatilized wine and common wine volatiles (acids, esters, alcohols) were added to synthetic wine samples to act as matrices. Sulfur standards were added and analyzed using gas chromatography with pulsed-flame photometric detection (GC-PFPD). Five internal standards were used to find best representatives of each compound despite matrix effects. Sensitivity remained stable with the addition of devolatilized wine, while addition of volatile components decreased sensitivity. DMS was found to be best measured against EMS; DMDS and the thioacetates were best measured against DES; H₂S, MeSH, DEDS, and DMTS were best measured against DIDS. The method was used to quantitate the volatile sulfur compounds in 21 wines with various ethanol contents and volatile profiles. Full article

This article considers key determinants of terroir tourism in the context of organic vineyards in Oregon, US. Emerging from anthropology, climatology, ecology, geography and wine tourism, terroir tourism has been recently recognized to have potential for developing tourism in Oregon. However, research has sought to determine terroir tourism and its characteristics, differentiating it from wine tourism. This case of Oregon will investigate a wine territory through the examination of organic vineyards. The relative importance of terroir within the organic vineyard destinations of Oregon is examined. Determining the characteristics of terroir tourism from a review on terroir and the experience economy 4E framework on wine tourism develops the case into organic vineyards with terroir tourism characteristics. Ultimately, an attempt to further develop wine tourism destinations based on their unique terroir esthetic experiences, and the potential for terroir tourism within the experience economy, is developed. Full article

There are many interactions that occur between taste and aroma that may impact perception. The main objective of this study was to ascertain whether the aroma fraction of wine should be considered when investigating relationships between chemical composition and sensory perception of mouthfeel. Chardonnay wines with different mouthfeels were produced by altering the fermentation temperature (15 °C and 21 °C) of the alcoholic and malolactic fermentations (MLF) as well as the timing of MLF and the presence of a non-Saccharomyces yeast during alcoholic fermentation. Napping^® and Ultra-flash-profiling were conducted using a panel of white winemakers. Each procedure was conducted twice: once with retro-nasal aroma (+R) and once without retronasal aroma (−R). Napping^® results showed that retronasal aroma impacted mouthfeel perception. Ultra-flash profiling of +R and −R displayed similar descriptive terms used. Several terms appear to be related to retronasal aroma as they were used in +R and not in −R. It is unclear if these terms are due to interactions or due to associated learning. These results suggest that for some mouthfeel terms the volatile fraction plays a role and, to establish relationships between chemical composition and mouthfeel perception, it is important to consider both the volatile and nonvolatile wine fractions. Full article