RESUMEN
The frequency and intensity of wildfires have been increasing over the last 50 years and negatively impacted the wine industry. Previous methods of smoke mitigation during grape processing have shown little impact in reducing smoke taint in wines. Therefore, a novel method of using edible spray coatings for vineyard application was developed to help prevent volatile smoke phenol uptake in wine grapes. Four cellulose nanofiber-based coating suspensions incorporated with chitosan and/or ß-cyclodextrin were evaluated. Films derived from the coating suspensions were exposed to volatile phenols found in wildfire smoke (guaiacol, 4-methyl guaiacol, m-cresol, o-cresol, p-cresol, syringol, and 4-methyl syringol) and evaluated with ultraviolet-visible spectroscopy where the results indicated that the coatings could uptake smoke phenols in varying degrees. The coatings were also applied in a vineyard at three different application times during grape growth: pea-sized, pre-bunch closure, and both at pea-sized and pre-bunch closure. The results showed that the application time did not have a significant (p < 0.05) effect on berry size, weight, °Brix, pH, or titratable acidity. The type of coating, time of application and washing were found to impact the number of volatile phenols in the grapes after a smoke event. Results from this study indicated that edible coatings could help mitigate smoke uptake in wine grapes without sacrificing the growth and key composition parameters of wine grapes. PRACTICAL APPLICATION: This research provides a novel spray coating that can be applied to wine grapes in the vineyard to potentially mitigate volatile smoke compounds in wine grapes without impacting fruit growth and key compositional parameters of wine grapes, thus maintaining high quality of wines for consumers. Results from this study can also be potentially applied to other agricultural commodities to solve the issues caused by the wildfire smoke.
Asunto(s)
Vitis , Compuestos Orgánicos Volátiles , Vino , Vitis/química , Humo/análisis , Fenoles/análisis , Vino/análisis , Frutas/química , Guayacol/análisis , Compuestos Orgánicos Volátiles/análisisRESUMEN
Wine quality and character are defined in part by the terroir in which the grapes are grown. Metabolomic techniques, such as nuclear magnetic resonance (NMR) spectroscopy and inductively coupled plasma mass spectrometry (ICP-MS), are used to characterise wines and to detect wine fraud in other countries but have not been extensively trialled in Australia. This paper describes the use of ICP-MS and NMR to characterise a selection of Pinot noir wines. Wines from varying terroirs could be somewhat distinguished by their mineral content using principal component analysis (PCA). PCA was able to separate wines by their Australian states more clearly than by region. Metabolomic analysis of the wines using NMR did not find any correlations with climate/daytime temperatures, or region. An analysis of coinertia suggested that the two datasets were not redundant, and it is proposed that ICP-MS data is the most useful for determining regionality.
Asunto(s)
Análisis de los Alimentos/métodos , Espectroscopía de Resonancia Magnética/métodos , Espectrometría de Masas/métodos , Vino/análisis , Australia , Clima , Análisis de los Alimentos/estadística & datos numéricos , Metabolómica , Nueva Zelanda , Análisis de Componente Principal , Temperatura , Vitis/química , Vitis/metabolismoRESUMEN
The compositional authentication of wine is of great interest, as the geographic origin of the grapes is often associated with quality, uniqueness, and authenticity. Previous elemental fingerprinting studies mainly discriminated wines from different countries or regions within a country. Here, we report the use of element profiles to distinguish commercial Pinot noir wines from five sub-regional appellations or neighborhoods within one American viticultural area (AVA). Fifty-three single cultivar wines were collected over two harvests and analyzed using microwave plasma-atomic emission spectroscopy (MP-AES) and inductively coupled plasma-mass spectrometry (ICP-MS). Of 62 monitored elements that were quantified with fully validated methods, 24 and 32 elements differed significantly across the neighborhoods and vintages, respectively (p < 0.05). Targeted canonical variate analysis (CVA) explained 85%-90% of the variance ratio across the two vintages, indicating persistent and stable elemental fingerprints of wines at a sub-regional level. A sixth, newly founded neighborhood was correctly grouped separately from the others using a Soft Independent Modeling of Class Analogy (SIMCA), indicating the potential of elemental fingerprints for wine authenticity.
Asunto(s)
Oligoelementos/química , Vitis/química , Vino , Inocuidad de los Alimentos , Espectrofotometría AtómicaRESUMEN
The ability of Patagonian L. plantarum and O. oeni strains to change the volatile profile of a sterile Pinot noir wine was studied through fermentation assays, at laboratory scale. Two strains of each LAB species were selected based on data regarding to their ability to survive in wine and to consume l-malic acid. Both O. oeni strains but only one L. plantarum (UNQLp 11) strain were able to remain viable, consuming l-malic acid through the fermentation assay with a concomitant increase of l-lactic acid. The volatile profile of Pinot noir wine, before and after LAB inoculation, was measured by using HS-SPME gas chromatography technique. This analysis showed that alcohols were the main volatile compounds after alcoholic fermentation and that after fermentation with the selected LAB strains, a decrease in the volatile alcohols concentration and an increase in the volatile esters concentration could be observed. The O. oeni UNQOe 73.2 strain produced the most notable change in the volatile profile, with the production of some important odorant esters at higher concentration, compared to O. oeni UNQOe 31b strain. Although, L. plantarum UNQLp 11 strain showed a better performance in the consumption of l-malic acid, this strain had a low capacity to modify the volatile compounds profile after incubation in red wine. The results found in the present work showed that different strains selected as potential malolactic starters could have different behavior when are incubated in real wine. Although L. plantarum UNQLp 11 strain showed a good consumption of l-malic acid, the O. oeni UNQOe 73.2 strain exhibited superior capacity to improve the flavor of wine due to its esterase activity that produce an increase of fruity and creamy odorants.
Asunto(s)
Fermentación , Lactobacillus plantarum/metabolismo , Odorantes/análisis , Oenococcus/metabolismo , Vitis , Compuestos Orgánicos Volátiles/metabolismo , Vino/análisis , Alcoholes/metabolismo , Cromatografía de Gases , Esterasas/metabolismo , Ésteres/metabolismo , Manipulación de Alimentos/métodos , Frutas , Humanos , Lactobacillus plantarum/clasificación , Lactobacillus plantarum/crecimiento & desarrollo , Malatos , Oenococcus/crecimiento & desarrollo , Especificidad de la EspecieRESUMEN
The impacts of fruit zone leaf removal on volatile and anthocyanin compositions of Pinot noir wine were investigated over two growing seasons. Wine volatiles were analyzed by multiple techniques, including headspace solid phase microextraction-GC-MS (HS-SPME-GC-MS), headspace-GC-FID (HS-GC-FID) and stir bar sorptive extraction-GC-MS (SBSE-GC-MS). Fruit zone leaf removal affected the concentration of many grape-derived volatile compounds such as terpene alcohols and C13-norisoprenoids in wine, although the degree of impact depended on the vintage year and severity of leaf removal. Fruit zone leaf removal resulted in greater concentrations of linalool, α-terpineol and ß-damascenone but had no impact on other terpene alcohols or ß-ionone. Fruit zone leaf removal had no consistent impact on C6 alcohols, volatile phenols, lactones, fermentation-derived alcohols, acids, or most esters. Fruit zone leaf removal increased anthocyanins in final wine.
Asunto(s)
Antocianinas/análisis , Hojas de la Planta/química , Vino/análisis , Agricultura/métodos , Alcoholes/análisis , Monoterpenos Ciclohexánicos , Ciclohexenos/análisis , Análisis de los Alimentos/métodos , Frutas/química , Cromatografía de Gases y Espectrometría de Masas , Concentración de Iones de Hidrógeno , Monoterpenos/análisis , Norisoprenoides/análisis , Oregon , Fenoles/análisis , Microextracción en Fase Sólida , Temperatura , Terpenos/análisis , Vitis/químicaRESUMEN
Five different methodologies were applied for the quantitative analysis of 86 volatile molecules in 32 Chardonnay and 30 Pinot Noir Champagne white base wines. Sensory characterization was carried out by descriptive analysis. Pinot Noir wines had more constitutive compounds while Chardonnay wines had more discriminant compounds. Only four compounds predominated in Chardonnay wines: 4-vinylphenol, guaiacol, sotolon and 4-methyl-4-mercapto-2-pentanone. Correlation studies and PLSR models were calculated with sensory and chemical variables. For Pinot Noir wines, they were not as revealing as for Chardonnay base wines. Sulfur-related compounds were suggested to be involved in tropical fruit, dried fruit and citric sensory notes. This family of compounds seemed to be responsible for discriminant sensory terms in Champagne base wines. Fermentative compounds (aromatic buffer) were found at significantly higher levels in Pinot Noir wines, which would explain the fact that these wines were more difficult to describe in comparison with Chardonnay base wines.
Asunto(s)
Compuestos Orgánicos Volátiles/análisis , Vino/análisis , Adulto , Femenino , Francia , Furanos/análisis , Guayacol/análisis , Humanos , Masculino , Persona de Mediana Edad , Fenoles/análisis , Olfato , Compuestos de Sulfhidrilo/análisis , Compuestos de Azufre/análisisRESUMEN
The effect of canopy leaf removal and ultraviolet (UV) on Pinot noir grape and wine composition was investigated in this study. Limited basal leaf removal in the fruit zone was conducted, compared to shaded bunches. The UV exposure was controlled using polycarbonate screens to block UV radiation, and acrylic screens to pass the UV. The results showed that bunch sunlight and UV exposure significantly increased the Brix and pH in the grape juice, and increased substantially wine colour density, anthocyanins, total pigment, total phenolics and tannin content. Bunch sunlight and UV exposure affected terpene alcohols, C13-norisprenoids and other volatile composition of the wine differently. Sunlight exposure and UV resulted in increase of nerol, geraniol and citronellol but not linalool. Sunlight exposure slightly increased the concentration of ß-ionone, but the increase was not statistically significant for UV treatment. Neither sunlight nor UV treatment showed any impact on the concentration of ß-damascenone.
Asunto(s)
Frutas/química , Fenoles/análisis , Luz Solar , Rayos Ultravioleta , Vitis/crecimiento & desarrollo , Vino/análisis , Antocianinas/análisis , Color , Frutas/crecimiento & desarrollo , Frutas/efectos de la radiación , Norisoprenoides/análisis , Taninos/análisis , Compuestos Orgánicos Volátiles/análisisRESUMEN
The relationship between grapevine vigour and grape and wine composition was investigated in this study. Own-rooted Pinot Noir grapevines were grown in a commercial vineyard in Tasmania, Australia, with uniform vineyard management practices. Vine vigours were determined by plant cell density (PCD) obtained from aerial photography. As vine vigour decreased, total soluble solid in grapes, total phenolics and anthocyanins in wines increased, while titratable acidity and yield decreased. Wines from the ultra low vine vigour zone had the highest concentrations of esters and alcohols. Higher level of linalool, nerol, geraniol, vitispirane, and ß-ionone were observed in ultra low vigour and low vigour zones, but there was no obvious trend for citronellol and ß-damascenone. Principal component analysis and discriminant analysis of the volatiles illustrated the differences among wines from the four vine vigour zones.