Scott C Frost, J. Sánchez, Caroline P. Merrell, R. Larsen, H. Heymann, J. Harbertson
Adjusting the soluble solids of the prefermentation must is a tool by which winemakers can manipulate the flavor profile of a wine. Total soluble solids (TSS) are often modified prior to fermentation by chaptalization or the addition of water, but can be modified also in the vineyard, by allowing the fruit to further mature on the vine. This work presents the effects of harvest maturity and prefermentation TSS on the flavor profile of Cabernet Sauvignon (CS) and Syrah (SY) wines. Fruit from each cultivar was harvested at three approximate maturity targets: 20 Brix (unripe), 24 Brix (ripe), and 28 Brix (overripe). Must from each harvest was first divided, then the TSS was adjusted to match each of the target maturities; for example, portions of the 24 Brix harvest were adjusted to 20 or 28 Brix. Descriptive analysis found 10 attributes that varied significantly among the CS wines and 14 attributes which varied significantly among the SY wines. Harvest maturity primarily impacted the CS aroma profile, as wines produced from unripe fruit showed increased green aroma, but wines produced from ripe/overripe fruit showed increased jammy berries aroma. Increasing the prefermentation TSS of the CS must increased the intensity of bitterness, hotness, and viscosity, but decreased the sourness. The SY wine flavor profile was impacted heavily by increasing the prefermentation TSS, which showed greater intensities of astringency, ethanol aroma, hot mouthfeel, jammy fruit aroma, rose aroma, solvent aroma, ethanol aroma, and viscous mouthfeel. SY fruit maturity significantly affected astringency and earthy aroma, but an interactive effect between harvest maturity and TSS was found for sulfur, cabbage aroma, and bitterness.
{"title":"Sensory Evaluation of Syrah and Cabernet Sauvignon Wines: Effects of Harvest Maturity and Prefermentation Soluble Solids","authors":"Scott C Frost, J. Sánchez, Caroline P. Merrell, R. Larsen, H. Heymann, J. Harbertson","doi":"10.5344/ajev.2020.20035","DOIUrl":"https://doi.org/10.5344/ajev.2020.20035","url":null,"abstract":"Adjusting the soluble solids of the prefermentation must is a tool by which winemakers can manipulate the flavor profile of a wine. Total soluble solids (TSS) are often modified prior to fermentation by chaptalization or the addition of water, but can be modified also in the vineyard, by allowing the fruit to further mature on the vine. This work presents the effects of harvest maturity and prefermentation TSS on the flavor profile of Cabernet Sauvignon (CS) and Syrah (SY) wines. Fruit from each cultivar was harvested at three approximate maturity targets: 20 Brix (unripe), 24 Brix (ripe), and 28 Brix (overripe). Must from each harvest was first divided, then the TSS was adjusted to match each of the target maturities; for example, portions of the 24 Brix harvest were adjusted to 20 or 28 Brix. Descriptive analysis found 10 attributes that varied significantly among the CS wines and 14 attributes which varied significantly among the SY wines. Harvest maturity primarily impacted the CS aroma profile, as wines produced from unripe fruit showed increased green aroma, but wines produced from ripe/overripe fruit showed increased jammy berries aroma. Increasing the prefermentation TSS of the CS must increased the intensity of bitterness, hotness, and viscosity, but decreased the sourness. The SY wine flavor profile was impacted heavily by increasing the prefermentation TSS, which showed greater intensities of astringency, ethanol aroma, hot mouthfeel, jammy fruit aroma, rose aroma, solvent aroma, ethanol aroma, and viscous mouthfeel. SY fruit maturity significantly affected astringency and earthy aroma, but an interactive effect between harvest maturity and TSS was found for sulfur, cabbage aroma, and bitterness.","PeriodicalId":7461,"journal":{"name":"American Journal of Enology and Viticulture","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2020-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42435985","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jared Johnson, Mengying Fu, M. Qian, C. Curtin, J. Osborne
This study investigated the effect of select non-Saccharomyces yeast strains on Hanseniaspora uvarum growth and acetic acid and ethyl acetate production during prefermentation cold soak. We tested commercially available non-Saccharomyces yeasts for their ability to reduce H. uvarum growth and acetic acid production during a simulated cold soak in a grape juice-based medium. All tested non-Saccharomyces yeast reduced H. uvarum growth and acetic acid production, with some yeast having a greater impact than others. Following the screening of non-Saccharomyces yeast, we tested 14 different H. uvarum isolates against a selected non-Saccharomyces yeast, Metschnikowia fructicola, and found that all H. uvarum isolates had reduced growth and acetic acid production when grown in co-culture with M. fructicola, with variation between isolates noted. Finally, we evaluated the effect of M. fructicola on H. uvarum during prefermentation cold soak of Pinot noir grapes. Pinot noir grapes were inoculated with a combination of H. uvarum and M. fructicola and cold soaked for six days at 8°C. At the end of cold soaking, treatments inoculated with M. fructicola contained lower populations of H. uvarum and significantly lower acetic acid and ethyl acetate concentrations compared with treatments not inoculated with M. fructicola. After the completion of alcoholic fermentation, wines where M. fructicola was added contained significantly lower ethyl acetate but no differences in acetic acid concentration. These results suggest that adding select non-Saccharomyces yeast may be another method to reduce the risk of spoilage by H. uvarum during prefermentation cold soaking.
{"title":"Influence of Select Non-Saccharomyces Yeast on Hanseniaspora uvarum Growth during Prefermentation Cold Maceration","authors":"Jared Johnson, Mengying Fu, M. Qian, C. Curtin, J. Osborne","doi":"10.5344/ajev.2020.20004","DOIUrl":"https://doi.org/10.5344/ajev.2020.20004","url":null,"abstract":"This study investigated the effect of select non-Saccharomyces yeast strains on Hanseniaspora uvarum growth and acetic acid and ethyl acetate production during prefermentation cold soak. We tested commercially available non-Saccharomyces yeasts for their ability to reduce H. uvarum growth and acetic acid production during a simulated cold soak in a grape juice-based medium. All tested non-Saccharomyces yeast reduced H. uvarum growth and acetic acid production, with some yeast having a greater impact than others. Following the screening of non-Saccharomyces yeast, we tested 14 different H. uvarum isolates against a selected non-Saccharomyces yeast, Metschnikowia fructicola, and found that all H. uvarum isolates had reduced growth and acetic acid production when grown in co-culture with M. fructicola, with variation between isolates noted. Finally, we evaluated the effect of M. fructicola on H. uvarum during prefermentation cold soak of Pinot noir grapes. Pinot noir grapes were inoculated with a combination of H. uvarum and M. fructicola and cold soaked for six days at 8°C. At the end of cold soaking, treatments inoculated with M. fructicola contained lower populations of H. uvarum and significantly lower acetic acid and ethyl acetate concentrations compared with treatments not inoculated with M. fructicola. After the completion of alcoholic fermentation, wines where M. fructicola was added contained significantly lower ethyl acetate but no differences in acetic acid concentration. These results suggest that adding select non-Saccharomyces yeast may be another method to reduce the risk of spoilage by H. uvarum during prefermentation cold soaking.","PeriodicalId":7461,"journal":{"name":"American Journal of Enology and Viticulture","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2020-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.5344/ajev.2020.20004","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43023445","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
New barrels (16 L) differing by oak species (Quercus alba or Q. petraea) and toasting level (light or heavy) were infected with Brettanomyces bruxellensis. Infected staves were sawed into 3 cm × 3 cm cubes and immersed 2 mm into red wine (11 or 15% v/v alcohol) that had been heated to 35, 40, 45, or 50°C. After removal from the wine, cubes were either sawed into cross sections or prepared as oak shavings before transfer to a yeast recovery medium and incubated for ≥30 days (cross sections) or for 12 hr (shavings) to recover culturable populations and calculate decimal reduction times (DT-values). Culturable cells were not recovered from inner cross sectional layers (0 to 4 mm depth) after heating in 11% v/v alcohol wine at 45 or 50°C, whereas populations were destroyed at deeper depths (e.g., 5 to 9 mm) using wines of 15% v/v alcohol at these same temperatures. In agreement, DT-values were greater when cubes were heated in 11% v/v alcohol wines (D45°C = 46 sec, D50°C = 30 sec) compared to wines with 15% v/v alcohol (D45°C = 17 sec, D50°C = 9 sec). Compared to heated water or steam, warmed-wine treatments required lower temperatures to remove the same degree of microbial contamination, in particular at inner stave depths ≤4 mm. Similar observations were noted for commercial barrels (225 L) previously infected by unidentified (in-house) strains of B. bruxellensis. Thus, application of warmed wine to infected barrels may serve as a method to greatly reduce populations of B. bruxellensis when temperatures lower than those needed for hot water or steam treatment are desired.
{"title":"Efficacy of Warmed Wine Against Brettanomyces bruxellensis Present in Oak Barrel Staves","authors":"Z. Cartwright, C. G. Edwards","doi":"10.5344/ajev.2020.19082","DOIUrl":"https://doi.org/10.5344/ajev.2020.19082","url":null,"abstract":"New barrels (16 L) differing by oak species (Quercus alba or Q. petraea) and toasting level (light or heavy) were infected with Brettanomyces bruxellensis. Infected staves were sawed into 3 cm × 3 cm cubes and immersed 2 mm into red wine (11 or 15% v/v alcohol) that had been heated to 35, 40, 45, or 50°C. After removal from the wine, cubes were either sawed into cross sections or prepared as oak shavings before transfer to a yeast recovery medium and incubated for ≥30 days (cross sections) or for 12 hr (shavings) to recover culturable populations and calculate decimal reduction times (DT-values). Culturable cells were not recovered from inner cross sectional layers (0 to 4 mm depth) after heating in 11% v/v alcohol wine at 45 or 50°C, whereas populations were destroyed at deeper depths (e.g., 5 to 9 mm) using wines of 15% v/v alcohol at these same temperatures. In agreement, DT-values were greater when cubes were heated in 11% v/v alcohol wines (D45°C = 46 sec, D50°C = 30 sec) compared to wines with 15% v/v alcohol (D45°C = 17 sec, D50°C = 9 sec). Compared to heated water or steam, warmed-wine treatments required lower temperatures to remove the same degree of microbial contamination, in particular at inner stave depths ≤4 mm. Similar observations were noted for commercial barrels (225 L) previously infected by unidentified (in-house) strains of B. bruxellensis. Thus, application of warmed wine to infected barrels may serve as a method to greatly reduce populations of B. bruxellensis when temperatures lower than those needed for hot water or steam treatment are desired.","PeriodicalId":7461,"journal":{"name":"American Journal of Enology and Viticulture","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2020-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.5344/ajev.2020.19082","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43077775","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. Scharfetter, Andi Nelson, B. Workmaster, A. Atucha
Currently, growers and winemakers of cold climate interspecific hybrid grape (CCIHG) cultivars rely solely on the technological maturity variables Brix, titratable acidity (TA), and pH as ripening indicators for harvest and winemaking decisions. In contrast, using additional chemical variables to determine optimal harvest times is a common practice in most regions of the world where the European grape Vitis vinifera is cultivated. As there are significant differences in berry chemistry between CCIHG and V. vinifera, the objective of the present study was to evaluate, by linear regression coupled with principal component analysis and cluster analysis, the suitability of six additional maturity variables (berry fresh weight, total protein, total phenolics, monomeric anthocyanins, percent polymeric color, and total tannins) as potential ripening indicators for the CCIHG cultivars Brianna, Frontenac, La Crescent, Léon Millot, Maréchal Foch, Marquette, MN 1220, and Petite Pearl. We observed that berry fresh weight, total phenolics, and percent polymeric color had inconsistent and difficult-to-model relationships from year to year and across distinct grape cluster microclimate treatments, making them unsuitable as ripening indicators. In addition to the standard technological maturity variables of Brix, TA, and pH, the variables of total protein concentration for white cultivars and of monomeric anthocyanin, total protein, and total tannin concentrations for red cultivars have consistent linear relationships from veraison to harvest, making them good candidates for ripening indicators.
{"title":"Evaluation of Ripening Indicators for Harvest-time Decision Making in Cold Climate Grape Production","authors":"J. Scharfetter, Andi Nelson, B. Workmaster, A. Atucha","doi":"10.5344/ajev.2020.20022","DOIUrl":"https://doi.org/10.5344/ajev.2020.20022","url":null,"abstract":"Currently, growers and winemakers of cold climate interspecific hybrid grape (CCIHG) cultivars rely solely on the technological maturity variables Brix, titratable acidity (TA), and pH as ripening indicators for harvest and winemaking decisions. In contrast, using additional chemical variables to determine optimal harvest times is a common practice in most regions of the world where the European grape Vitis vinifera is cultivated. As there are significant differences in berry chemistry between CCIHG and V. vinifera, the objective of the present study was to evaluate, by linear regression coupled with principal component analysis and cluster analysis, the suitability of six additional maturity variables (berry fresh weight, total protein, total phenolics, monomeric anthocyanins, percent polymeric color, and total tannins) as potential ripening indicators for the CCIHG cultivars Brianna, Frontenac, La Crescent, Léon Millot, Maréchal Foch, Marquette, MN 1220, and Petite Pearl. We observed that berry fresh weight, total phenolics, and percent polymeric color had inconsistent and difficult-to-model relationships from year to year and across distinct grape cluster microclimate treatments, making them unsuitable as ripening indicators. In addition to the standard technological maturity variables of Brix, TA, and pH, the variables of total protein concentration for white cultivars and of monomeric anthocyanin, total protein, and total tannin concentrations for red cultivars have consistent linear relationships from veraison to harvest, making them good candidates for ripening indicators.","PeriodicalId":7461,"journal":{"name":"American Journal of Enology and Viticulture","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2020-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.5344/ajev.2020.20022","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47961208","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
G. Sacks, Patricia A. Howe, M. Standing, J. Danilewicz
Recent work has evaluated the kinetics of free and total sulfur dioxide (SO2) loss in wine following aerial exposure, but little work exists on the relationship between free and total SO2 during the oxidation conditions expected during wine storage. We report changes in free and total SO2 in three wines (Chardonnay, Merlot, and Cabernet Sauvignon) stored for up to 400 days at 19 or 31°C in different bag-in-box packages. The rate of total SO2 loss varied up to seven-fold for a given wine across storage conditions, e.g., 0.13 to 0.94 mg/L SO2 loss per day for the Chardonnay. Total rates of SO2 loss were linear even after free SO2 was undetectable, and only strongly bound SO2 remained. This finding indicated that bound SO2 adduct hydrolysis was fast, as compared to the rate of SO2 consumption in these packaged wines, likely because the SO2 consumption rate depended on the oxygen ingress rate. Total versus free SO2 plots were linear for free SO2 concentrations greater than ~5 mg/L. The slope (Δtotal/Δfree) of this linear region was wine dependent (Chardonnay = 1.33 to 1.49; Merlot = 1.91 to 2.10; Cabernet Sauvignon = 1.83 to 2.00). In contrast to the rate of total SO2 loss, this ratio varied negligibly with storage conditions, suggesting that minimal formation of new SO2 binders occurred over the course of oxidation. The apparent adduct dissociation equilibrium constant (Kd) of each wine as a function of free SO2 concentration was determined from the first derivative of [Bound]/[Free] versus [Free] plots (“Burroughs plots”). As free SO2 decreased to <10 mg/L, the apparent Kd values decreased to values between 1 × 10-4 M and 10-5 M, which are comparable to those reported for malodorous aldehydes.
{"title":"Free, Bound, and Total Sulfur Dioxide (SO2) during Oxidation of Wines","authors":"G. Sacks, Patricia A. Howe, M. Standing, J. Danilewicz","doi":"10.5344/ajev.2020.19083","DOIUrl":"https://doi.org/10.5344/ajev.2020.19083","url":null,"abstract":"Recent work has evaluated the kinetics of free and total sulfur dioxide (SO2) loss in wine following aerial exposure, but little work exists on the relationship between free and total SO2 during the oxidation conditions expected during wine storage. We report changes in free and total SO2 in three wines (Chardonnay, Merlot, and Cabernet Sauvignon) stored for up to 400 days at 19 or 31°C in different bag-in-box packages. The rate of total SO2 loss varied up to seven-fold for a given wine across storage conditions, e.g., 0.13 to 0.94 mg/L SO2 loss per day for the Chardonnay. Total rates of SO2 loss were linear even after free SO2 was undetectable, and only strongly bound SO2 remained. This finding indicated that bound SO2 adduct hydrolysis was fast, as compared to the rate of SO2 consumption in these packaged wines, likely because the SO2 consumption rate depended on the oxygen ingress rate. Total versus free SO2 plots were linear for free SO2 concentrations greater than ~5 mg/L. The slope (Δtotal/Δfree) of this linear region was wine dependent (Chardonnay = 1.33 to 1.49; Merlot = 1.91 to 2.10; Cabernet Sauvignon = 1.83 to 2.00). In contrast to the rate of total SO2 loss, this ratio varied negligibly with storage conditions, suggesting that minimal formation of new SO2 binders occurred over the course of oxidation. The apparent adduct dissociation equilibrium constant (Kd) of each wine as a function of free SO2 concentration was determined from the first derivative of [Bound]/[Free] versus [Free] plots (“Burroughs plots”). As free SO2 decreased to <10 mg/L, the apparent Kd values decreased to values between 1 × 10-4 M and 10-5 M, which are comparable to those reported for malodorous aldehydes.","PeriodicalId":7461,"journal":{"name":"American Journal of Enology and Viticulture","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2020-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.5344/ajev.2020.19083","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49551524","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Carew, F. Kerslake, K. Bindon, P. Smith, D. Close, R. Dambergs
Pinot noir fruit is often relatively low in the phenolics important for wine mouthfeel and color stabilization. Previous research has shown that leaf removal can influence the concentration and composition of Pinot noir fruit phenolics, but it is not clear to what extent these effects on grape composition are carried through the winemaking process. A novel thermal treatment, Controlled Phenolic Release (CPR), has been demonstrated to be effective for increasing the phenolic concentration of Pinot noir wines, but there is currently limited information on the interaction between this process and viticultural practices. CPR is microwave heating of grape must to hasten phenolic extraction. This study applied viticultural treatments to Pinot noir (no leaf removal, leaf removal at postflowering and preveraison) in two commercial vineyards (A and B), and winemaking treatments in replicated microvinifications (control, CPR with skin contact, CPR with early pressing) were applied to fruit from vineyard A. Effects on grape and wine phenolics were examined using UV-visible spectrophotometry. Wine tannin composition and polymerization were assayed by methyl cellulose precipitation and high-performance liquid chromatography. Viticultural treatments applied produced significant effects in vineyard A but not in vineyard B. Winemaking treatments affected the concentration of phenolics in wines, but there was no interaction between viticultural and winemaking treatments; effects were additive. Of scientific and practical significance was the finding that grape phenolic concentration determined from homogenate extractions of fruit did not reliably predict Pinot noir wine phenolics. Furthermore, in wines, variation in tannin composition, the extent of tannin polymerization, and tannin size was found between treatments. The novel findings here are that the viticultural treatment and the winemaking treatments were both significant and, being independent of each other, offered two separate ways to adjust phenolics in Pinot noir wine. Viticultural and winemaking treatments were also shown to affect tannin composition, with potential mouthfeel and color stability implications.
{"title":"Viticultural and Controlled Phenolic Release Treatments Affect Phenolic Concentration and Tannin Composition in Pinot noir Wine","authors":"A. Carew, F. Kerslake, K. Bindon, P. Smith, D. Close, R. Dambergs","doi":"10.5344/ajev.2020.19003","DOIUrl":"https://doi.org/10.5344/ajev.2020.19003","url":null,"abstract":"Pinot noir fruit is often relatively low in the phenolics important for wine mouthfeel and color stabilization. Previous research has shown that leaf removal can influence the concentration and composition of Pinot noir fruit phenolics, but it is not clear to what extent these effects on grape composition are carried through the winemaking process. A novel thermal treatment, Controlled Phenolic Release (CPR), has been demonstrated to be effective for increasing the phenolic concentration of Pinot noir wines, but there is currently limited information on the interaction between this process and viticultural practices. CPR is microwave heating of grape must to hasten phenolic extraction. This study applied viticultural treatments to Pinot noir (no leaf removal, leaf removal at postflowering and preveraison) in two commercial vineyards (A and B), and winemaking treatments in replicated microvinifications (control, CPR with skin contact, CPR with early pressing) were applied to fruit from vineyard A. Effects on grape and wine phenolics were examined using UV-visible spectrophotometry. Wine tannin composition and polymerization were assayed by methyl cellulose precipitation and high-performance liquid chromatography. Viticultural treatments applied produced significant effects in vineyard A but not in vineyard B. Winemaking treatments affected the concentration of phenolics in wines, but there was no interaction between viticultural and winemaking treatments; effects were additive. Of scientific and practical significance was the finding that grape phenolic concentration determined from homogenate extractions of fruit did not reliably predict Pinot noir wine phenolics. Furthermore, in wines, variation in tannin composition, the extent of tannin polymerization, and tannin size was found between treatments. The novel findings here are that the viticultural treatment and the winemaking treatments were both significant and, being independent of each other, offered two separate ways to adjust phenolics in Pinot noir wine. Viticultural and winemaking treatments were also shown to affect tannin composition, with potential mouthfeel and color stability implications.","PeriodicalId":7461,"journal":{"name":"American Journal of Enology and Viticulture","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2020-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.5344/ajev.2020.19003","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41462075","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mary Jasinski, A. Reynolds, F. Di Profio, Audrey C. S. Pasquier, Maxime Touffet, Rea Fellman, Hyun-Suk Lee
Grapevine winter hardiness is governed by several factors besides extreme weather conditions, such as site-specific soil factors (texture, composition, moisture, drainage), vine water status, and yield. It was hypothesized that winter hardiness would be influenced by specific vineyard terroir-driven factors and that zones in vineyards with low water status (leaf water potential [Ψ]) would likewise be more winter hardy than vines with high water status (less negative leaf Ψ). Six Riesling vineyards were chosen throughout the Niagara region in Ontario. Data were collected at fruit set, lag phase, and veraison (soil water content [SWC], leaf Ψ), at harvest (yield components, berry composition), and three times during the winter (LT50; the temperature at which 50% of buds die) in 2010 to 2012. Interpolation and mapping of variables was completed using kriging, and statistical analyses (linear correlation, k-means clustering, principal components analysis, multilinear regression) were performed. SWC, leaf Ψ, yield components, berry composition, and LT50 were spatially clustered in each vineyard. GIS and multilinear regression revealed that leaf Ψ could predict the LT50 value, with strong correlations observed between LT50 and leaf Ψ values in most of the vineyard blocks in 2010 to 2011 (4/6 and 5/6, respectively). In the extremely dry 2012 season, leaf Ψ (range across sites at veraison 0.9 to 1.4 MPa) was positively correlated to LT50, yield, titratable acidity, pH, and Brix and inversely correlated to SWC and monoterpene concentration. Results suggest that there is a spatial component to winter hardiness, as with other aspects of terroir. This study allows a method to compare winter hardiness to other critical variables to better understand terroir-based factors of the Niagara region.
{"title":"Terroir of Winter Hardiness: Bud LT50, Water Metrics, Yield, and Berry Composition in Ontario Riesling","authors":"Mary Jasinski, A. Reynolds, F. Di Profio, Audrey C. S. Pasquier, Maxime Touffet, Rea Fellman, Hyun-Suk Lee","doi":"10.5344/ajev.2020.19084","DOIUrl":"https://doi.org/10.5344/ajev.2020.19084","url":null,"abstract":"Grapevine winter hardiness is governed by several factors besides extreme weather conditions, such as site-specific soil factors (texture, composition, moisture, drainage), vine water status, and yield. It was hypothesized that winter hardiness would be influenced by specific vineyard terroir-driven factors and that zones in vineyards with low water status (leaf water potential [Ψ]) would likewise be more winter hardy than vines with high water status (less negative leaf Ψ). Six Riesling vineyards were chosen throughout the Niagara region in Ontario. Data were collected at fruit set, lag phase, and veraison (soil water content [SWC], leaf Ψ), at harvest (yield components, berry composition), and three times during the winter (LT50; the temperature at which 50% of buds die) in 2010 to 2012. Interpolation and mapping of variables was completed using kriging, and statistical analyses (linear correlation, k-means clustering, principal components analysis, multilinear regression) were performed. SWC, leaf Ψ, yield components, berry composition, and LT50 were spatially clustered in each vineyard. GIS and multilinear regression revealed that leaf Ψ could predict the LT50 value, with strong correlations observed between LT50 and leaf Ψ values in most of the vineyard blocks in 2010 to 2011 (4/6 and 5/6, respectively). In the extremely dry 2012 season, leaf Ψ (range across sites at veraison 0.9 to 1.4 MPa) was positively correlated to LT50, yield, titratable acidity, pH, and Brix and inversely correlated to SWC and monoterpene concentration. Results suggest that there is a spatial component to winter hardiness, as with other aspects of terroir. This study allows a method to compare winter hardiness to other critical variables to better understand terroir-based factors of the Niagara region.","PeriodicalId":7461,"journal":{"name":"American Journal of Enology and Viticulture","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2020-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.5344/ajev.2020.19084","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42658468","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Malolactic fermentation (MLF) is an important step in winemaking to improve wine quality by deacidification, increased microbial stability, and modified wine flavor. The phenolic composition of the wine influences the growth and metabolism of the lactic acid bacteria (LAB) used for MLF. Due to increased cultivation of fungus-resistant grape cultivars, the present study aimed to analyze the influence of stilbenes on MLF because stilbenes play an important role as phytoalexins in plants to counteract fungal pathogens. The analysis showed that the grapevine-shoot extract Vineatrol and the stilbenes ε-viniferin, ampelopsin A, r2-viniferin, and r-viniferin, as well as mixtures of the five stilbenes, decelerated malic acid degradation. This can be partially attributed to a reduced number of viable cells. However, the direct impact of stilbenes on the malolactic enzyme must also play a role, as shown by the finding that the viability of LAB stabilized, while at the same time, malic acid degradation was reduced. These results show that wines made from stilbene-rich grapes, such as fungus-resistant cultivars, might have a higher risk for a sluggish or incomplete MLF.
{"title":"Stilbenes Can Impair Malolactic Fermentation with Strains of Oenococcus oeni and Lactobacillus plantarum","authors":"Sabrina Zimdars, Rita Caspers-Weiffenbach, Pascal Wegmann-Herr, Fabian Weber","doi":"10.5344/ajev.2020.20021","DOIUrl":"https://doi.org/10.5344/ajev.2020.20021","url":null,"abstract":"Malolactic fermentation (MLF) is an important step in winemaking to improve wine quality by deacidification, increased microbial stability, and modified wine flavor. The phenolic composition of the wine influences the growth and metabolism of the lactic acid bacteria (LAB) used for MLF. Due to increased cultivation of fungus-resistant grape cultivars, the present study aimed to analyze the influence of stilbenes on MLF because stilbenes play an important role as phytoalexins in plants to counteract fungal pathogens. The analysis showed that the grapevine-shoot extract Vineatrol and the stilbenes ε-viniferin, ampelopsin A, r2-viniferin, and r-viniferin, as well as mixtures of the five stilbenes, decelerated malic acid degradation. This can be partially attributed to a reduced number of viable cells. However, the direct impact of stilbenes on the malolactic enzyme must also play a role, as shown by the finding that the viability of LAB stabilized, while at the same time, malic acid degradation was reduced. These results show that wines made from stilbene-rich grapes, such as fungus-resistant cultivars, might have a higher risk for a sluggish or incomplete MLF.","PeriodicalId":7461,"journal":{"name":"American Journal of Enology and Viticulture","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2020-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.5344/ajev.2020.20021","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41817260","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
L. F. Casassa, Niclas P. Dermutz, P. Mawdsley, M. Thompson, A. Catania, Thomas S. Collins, P. L. Ashmore, Fintan du Fresne, Gregory Gasic, J. D. Dodson Peterson
The effect of additions of dried stems (DS) and whole clusters at 50% (50% WC) and 100% (100% WC) were investigated over two consecutive vintages of Pinot noir wines from the Edna Valley AVA of California (USA) at commercial scale. Addition of 100% WC led to significant increases in pH and volatile acidity. Anthocyanins, polymeric pigments, and color were more influenced by vintage than by the winemaking treatments, but they were unaffected or negatively affected in 100% WC wines. Conversely, the tannin content of the wines increased in accordance to the percentage of WC and stems added, with increases of 68% (50% WC), 100% (100% WC), and 90% (DS) in 2016 and 61% (50% WC), 123% (100% WC), and 137% (DS) in 2017 relative to control wines. Gas chromatography-mass spectrometry (GC-MS) data showed higher relative levels of ethyl cinnamate and benzaldehyde in 100% WC wines and relative abundance of esters in DS wines. Descriptive sensory analysis showed that 100% WC additions led to vegetal, cooked fruit flavors, and spicy (clove) notes, whereas DS additions produced wines that were more herbal, fruity, and astringent, with lifted fruity notes related to esters, and astringency sensations related to enhanced tannin extraction from the stems. Both WC and DS additions led to variable increases in perceived astringency, suggesting that they can be used to add mouthfeel and improve texture in Pinot noir wines.
{"title":"Whole Cluster and Dried Stem Additions’ Effects on Chemical and Sensory Properties of Pinot noir Wines over Two Vintages","authors":"L. F. Casassa, Niclas P. Dermutz, P. Mawdsley, M. Thompson, A. Catania, Thomas S. Collins, P. L. Ashmore, Fintan du Fresne, Gregory Gasic, J. D. Dodson Peterson","doi":"10.5344/ajev.2020.20037","DOIUrl":"https://doi.org/10.5344/ajev.2020.20037","url":null,"abstract":"The effect of additions of dried stems (DS) and whole clusters at 50% (50% WC) and 100% (100% WC) were investigated over two consecutive vintages of Pinot noir wines from the Edna Valley AVA of California (USA) at commercial scale. Addition of 100% WC led to significant increases in pH and volatile acidity. Anthocyanins, polymeric pigments, and color were more influenced by vintage than by the winemaking treatments, but they were unaffected or negatively affected in 100% WC wines. Conversely, the tannin content of the wines increased in accordance to the percentage of WC and stems added, with increases of 68% (50% WC), 100% (100% WC), and 90% (DS) in 2016 and 61% (50% WC), 123% (100% WC), and 137% (DS) in 2017 relative to control wines. Gas chromatography-mass spectrometry (GC-MS) data showed higher relative levels of ethyl cinnamate and benzaldehyde in 100% WC wines and relative abundance of esters in DS wines. Descriptive sensory analysis showed that 100% WC additions led to vegetal, cooked fruit flavors, and spicy (clove) notes, whereas DS additions produced wines that were more herbal, fruity, and astringent, with lifted fruity notes related to esters, and astringency sensations related to enhanced tannin extraction from the stems. Both WC and DS additions led to variable increases in perceived astringency, suggesting that they can be used to add mouthfeel and improve texture in Pinot noir wines.","PeriodicalId":7461,"journal":{"name":"American Journal of Enology and Viticulture","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2020-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.5344/ajev.2020.20037","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45637061","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Gaurab Bhattarai, A. Fennell, J. Londo, Courtney Coleman, L. Kovács
The viticulture industry needs advanced grape cultivars with genes that enhance disease resistance and environmental stress tolerance to meet the challenges of a changing climate. To discover beneficial allelic variants of grape genes, we established an F1 mapping population from a cross between two North American grapevines, Vitis rupestris Scheele and Vitis riparia Michx. We generated genotyping-by-sequencing (GBS) markers and constructed parental linkage maps consisting of 1177 and 1115 GBS markers, respectively (LOD threshold ≥ 14), which were validated by mapping the sex-determining locus to chromosome 2. Taking advantage of loci heterozygous in both parents, we also constructed an integrated map containing 2583 markers. We mapped a major quantitative trait locus (QTL) for downy mildew (Plasmopara viticola) resistance to chromosome 10 of V. rupestris using both greenhouse- and in vitro-generated leaf resistance data. This QTL explains 66.5% of the phenotypic variance under greenhouse conditions, and its 2-LOD confidence interval corresponds to region 2,470,297 to 3,024,940 bp on chromosome 10 in the Vitis vinifera L. PN40024 reference genome sequence (assembly 12X.v2). We provide PN40024-projected positions of the GBS markers, which can be used as anchors to develop additional markers for the introgression of this V. rupestris haplotype into cultivated grape varieties.
{"title":"A Novel Grape Downy Mildew Resistance Locus from Vitis rupestris","authors":"Gaurab Bhattarai, A. Fennell, J. Londo, Courtney Coleman, L. Kovács","doi":"10.5344/ajev.2020.20030","DOIUrl":"https://doi.org/10.5344/ajev.2020.20030","url":null,"abstract":"The viticulture industry needs advanced grape cultivars with genes that enhance disease resistance and environmental stress tolerance to meet the challenges of a changing climate. To discover beneficial allelic variants of grape genes, we established an F1 mapping population from a cross between two North American grapevines, Vitis rupestris Scheele and Vitis riparia Michx. We generated genotyping-by-sequencing (GBS) markers and constructed parental linkage maps consisting of 1177 and 1115 GBS markers, respectively (LOD threshold ≥ 14), which were validated by mapping the sex-determining locus to chromosome 2. Taking advantage of loci heterozygous in both parents, we also constructed an integrated map containing 2583 markers. We mapped a major quantitative trait locus (QTL) for downy mildew (Plasmopara viticola) resistance to chromosome 10 of V. rupestris using both greenhouse- and in vitro-generated leaf resistance data. This QTL explains 66.5% of the phenotypic variance under greenhouse conditions, and its 2-LOD confidence interval corresponds to region 2,470,297 to 3,024,940 bp on chromosome 10 in the Vitis vinifera L. PN40024 reference genome sequence (assembly 12X.v2). We provide PN40024-projected positions of the GBS markers, which can be used as anchors to develop additional markers for the introgression of this V. rupestris haplotype into cultivated grape varieties.","PeriodicalId":7461,"journal":{"name":"American Journal of Enology and Viticulture","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2020-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.5344/ajev.2020.20030","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49053218","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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