IVAS 2022 banner
IVES 9 IVES Conference Series 9 IVAS 9 IVAS 2022 9 Achieving Tropical Fruit Aromas in White Wine through Innovative Winemaking Processes

Achieving Tropical Fruit Aromas in White Wine through Innovative Winemaking Processes

Abstract

Tropical fruit aroma is highly desirable in certain white wine styles and there is a significant group of consumers that show preference for this aroma. While there is substantial work in relating tropical fruit aroma exclusively to volatile thiols, the assessment of any other compound and their interactions that may cause this aroma are yet unexplored. Previous work suggests that esters, when in combination with thiols in a wine media, play a role in tropical fruit perception as an aroma enhancer to thiol-related aroma attributes. Moreover, the highly fruity sensory profile of this family caused consumers and a trained panel to smell tropical fruit aromas in a wine model spiked with acetate and ethyl esters. In the same sensory study, samples that contained only thiols resulted in grass and earthy aromas, and not tropical fruit aromas as expected. Thus, this prior study showed that, while the presence of thiols is critical to tropical fruit perception, other aroma families, such as esters, also caused this aroma.
Considering that the presence of esters and thiols are crucial to tropical fruit aroma perception, the work herein investigated specific winemaking procedures that could increase both aroma families, esters and thiols, in white wines. Chardonnay grapes were harvested at the OSU Woodhall vineyard and processed at the OSU research winery during the 2020 vintage. The control (standard winemaking) and four treatments were evaluated: skin contact (10˚C for 18 hours), enzyme addition (β-lyase, 40 μl/L), and two fermentation gradient temperature procedures (FGT 1: start at 20˚C and after 100h change to 13˚C; FGT 2: start at 20˚C and after ~12˚Brix change to 13˚C). A full factorial design containing all possible treatment combinations was proposed, totaling 12 wines performed in triplicate, resulting in 36 microferments. To ensure that the results did not occur due to chance but due to the processes investigated, the design was fully repeated and the same procedures were followed, totaling 72 microferments. An ester method (HS-SPME GCMS) was developed to measure approximately 40 ethyl and acetate esters. The volatile thiols 3-MH, 3-MHA and 4-MMP were quantified using a method by Capone et al. (201%). A three-way ANOVA model was performed on the total concentrations of esters and thiols. Skin contact, fermentation gradient temperature and their interaction effect played a significant effect in the concentration of thiols. Significant differences were observed in skin contact and both FGT treatments for esters, but their interaction was not significant. Finally, the interaction of skin contact and FGT 1 resulted in the highest concentrations of both esters and thiols. As a future study, skin contact and FG 1 will be scaled up in a full factorial design to evaluate the sensory perception and consumer acceptance of these wines.

DOI:

Publication date: June 24, 2022

Issue: IVAS 2022

Type: Poster

Authors

Tomasino Elizabeth1 and Iobbi Angelica1

1Oregon State University

Contact the author

Keywords

Esters, skin contact, volatile thiols, fermentatiomn gradient, lyase

Tags

IVAS 2022 | IVES Conference Series

Citation

Related articles…

Combining effect of leaf removal and natural shading on grape ripening under two irrigation strategies in Manto negro (Vitis vinifera L.)

The increasingly frequent heat waves during grape ripening pose challenges for high quality wine grape production. Defoliation is a common practice that can improve the control of diseases in bunches, but also it increases the exposure to sunlight. Grapes exposed to solar radiation reach temperatures over the optimum for berry development and maturation. This makes the development of irrigation and canopy management techniques of great importance to maximize yield and grape quality. A field experiment was carried out during 2021 using Manto negro wine grapes to study the effect of applied irrigation and different light exposure levels on grape quality. Two irrigation treatments were imposed based on the frequency and amount of water doses in a four-block experimental vineyard at Bodega Ribas (Mallorca). Three light exposure treatments were randomly applied in each irrigation plot. The light treatments included exposed clusters from pea size, non-exposed clusters, and shaded clusters after softening. Leaf area index and canopy porosity was estimated every 2 weeks. Midday leaf water potential was measured weekly. Additionally, apparent electrical conductivity was measured between rows to estimate the soil water content variability. Light and temperature sensors were installed at the bunch level to quantify the differences in bunch temperature and light intensity among treatments. The effect of irrigation and cluster light exposure on berry weight, TSS, TA, malic acid, tartaric acid, K+, and pH were analysed at 5 moments along grape ripening. During different heat waves, the natural shading technique decreased the maximum bunch temperature around 10 °C respect to the exposed bunches in both irrigation strategies. The combination of defoliation and shading techniques after softening decreased TSS at harvest and affected most of the quality parameters during the last stages of ripening, showing an interesting technique to delay ripening in warm viticulture areas.

Climate, Viticulture, and Wine … my how things have changed!

The planet is warmer than at any time in our recorded past and increasing greenhouse emissions and persistence in the climate system means that continued warming is highly likely. Climate change has already altered the basic framework of growing grapes for wine production worldwide and will likely continue to do so for years to come. The wine sector can continue to play an important role in leading the agricultural sector in addressing climate change. From developing on…

The combined effects of climate, soils, and deficit irrigation on yield and quality of Touriga Nacional under high atmospheric demand in the Douro Region

Global warming is one of the biggest environmental, social and economic threats in several viticultural regions. In the Douro Valley, changes are expected in the coming years, namely an increase in temperature and a decrease in precipitation. These changes are likely to have consequences for the production and quality of wine.
The aim of this study was to explore the effects of different soil characteristics combined with several deficit irrigation strategies, managed throughout ETc references and predawn leaf water potentials thresholds, on physiology, yield, and qualitative attributes on the Touriga Nacional variety under years of mild to severe water and heat stress.
The studies were conducted over seven years (2015 to 2021) in two plots of a commercial vineyard located at Quinta do Ataíde (Symington Family Estates) planted in 2011 and 2014 at 170 meters elevation, growing under three water regimes: non-irrigated (NI) and two deficit irrigation strategies (30% and 60% ETc) assessed weekly by Ψpd. The site has an annual rainfall below 500 mm, with high atmospheric demand. Climate data was collected from a weather station, located on site. Berry ripening was followed weekly for fruit analysis. At harvest, yield, vigour and pruning weight per vine were determined from 90 vines by treatment. Each season at veraison the NDVI Index was accessed by a drone. The soils physic-chemistry in the experimental blocs were analysed and grouped by SWHC. Delta C-13 analyses were also performed per treatment in two years.Irrigation had a positive effect on yield per vine, mostly due to an increase in berry and cluster weight, and fertility index through the years. A significant increase in sugar content, colour and phenols was observed with deficit irrigation in some years, but vine vigour related to soil characteristics had by far the greatest impact on quality.

Projected changes in vine phenology of two varieties with different thermal requirements cultivated in La Mancha DO (Spain) under climate change scenarios

The aim of this work was to analyze the phenology variability of Tempranillo and Chardonnay cultivars, related to the climatic characteristics in La Mancha Designation of Origin, and their potential changes under climate change scenarios. Phenological dates referred to budbreak, flowering, veraison and harvest were analyzed for the period 2000-2019. The weather conditions at daily time scale, recorded during the same period, were also evaluated. The thermal requirements to reach each of these phenological stages were calculated and expressed as the GDD accumulated from DOY=60. Changes in phenology were projected by 2050 and 2070 taking into account those values and the projected temperatures and precipitation, simulated under two Representative Concentration Pathway (RCP) scenarios –RCP4.5 and RCP8.5– using an ensemble of models. The average phenological dates during the period under study were, April 16th ± 6.6 days and April 5th ± 6.0 days for budbreak, May 31st ± 6.0 days and May 27th ± 5.3 days for flowering, July 26th ± 5.6 days and July 25th ± 5.8 days for veraison, and Ago 23rd ± 10.8 days and Ago 17th ± 9.0 days for harvest, respectively, for Tempranillo and Chardonnay. The projected changes in temperature imply an average change in the maximum growing season (April-August) temperatures of 1.2 and 1.9°C by 2050, and 1.6 and 2.6°C by 2070, under the RCP4.5 and RCP8.5 scenarios, respectively. A reduction in precipitation is predicted, which vary between 15% for 2050 under RCP4.5 scenario and up to 30% by 2070 under RCP8.5. The advance of the phenological dates for 2050, could be of 6, 7, 7, and 8 days for Tempranillo and 4, 6, 6 and 9 days for Chardonnay, respectively for budbreak, flowering, veraison and harvest under the RCP4.5 scenario. Under the RCP8.5 emission scenario, the advance could be up to 30% higher.

Effects of graft quality on growth and grapevine-water relations

Climate change is challenging viticulture worldwide compromising its sustainability due to warmer temperatures and the increased frequency of extreme events. Grafting Vitis vinifera L.