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…

Impact of climate change on the viticultural climate of the Protected Designation of Origin “Jumilla” (SE Spain)

Protected Designation of Origin “Jumilla” (PDO Jumilla) is located in the Spanish provinces of Albacete and Murcia, in the South-eastern part of the Iberian Peninsula, where most of the models predict a severe impact of climate change in next decades. PDO Jumilla covers an area of 247,054 hectares, of which more than 22,000 hectares

Postveraison shoot trimming in Tannat and Merlot: preliminary results on yield components, plant balance and berry composition

There is currently a trend towards the production of wines with low alcohol content. To achieve this, grapes with low sugar content must be used. There are techniques at the vineyard level that can delay ripening and avoid excessive sugar accumulation without, a priori, affecting the final polyphenol content. Postveraison shoot trimming (PVST) is experimentally evaluated for these purposes, but its impact under Uruguayan climatic conditions with high interannual variability is not known. The aim of this work is to assess the PVST in Tannat and Merlot cultivars and their impact on yield components, plant balance and berry primary composition. In this study, two commercial vineyards of 10 years old Tannat and Merlot (grafted on SO4) at Canelones Department were selected. During the 2020-201 growing season, grapevines were submitted to PVST when grapes reached 15º Brix. In a randomized block, trimmed (T) and control (C) plants were evaluated with three repetitions each cultivar. Evaluation of the evolution of primary berry composition during ripening, measurement of yield components and plant balance were performed. For both cultivars, PVST did not affect yield components. Merlot reached 5.4 kg per plant and Tannat 7.1 kg, with not statistical significance between treatments. However, statistical differences were observed in terms of plant balance. In Merlot Ravaz Index reached a difference of 5.3 (12.0 in T and 6.7 in C) meanwhile Tannat reached 3.5 of statistical difference (13.7 in T and 10.2 in C). The tendency to imbalance for the treated plants had an impact on the final grape composition. Merlot grapes showed statistical difference in final total acidity (0.3 g of difference between treatments) while treatments impact final sugar content on Tannat grapes (10.0 g of difference between treatments). Further studies are needed to assess the impact of different canopy management techniques in our conditions.

Late frost protection in Champagne

Probably one of the most counterintuitive impacts of climate change on vine is the increased frequency of late frost. Champagne, due to its septentrional position is historically and regularly affected by this meteorological hazard. Champagne has therefore developed a strong experience in frost protection with first experiments dating from the end of 19th century. Frost protection can be divided in two parts: passive and active. Passive protection includes all the methods that do not seek to modify the vine’s environment or resistance at the time of frost. The most iconic passive protection in Champagne is the establishment of the individual reserve. This reserve allows to stock a certain quantity of clear wine during a surplus year to compensate a meteorological hazard like frost during the following years. Other common passive methods are the control of planting area (walls, bushes, topography), the choice of grape variety, late pruning, or the impact of grass cover and tillage. Active frost protection is also divided in two parts. Most of the existing techniques tend to modify vine’s environment. Most of the time they provide warmth (candles, heaters, windmills, heating cables…), or stabilise bud’s temperature above a lethal threshold (water sprinkling). The other way to actively fight is to enhance the resistance of buds to frost (elicitors). The Comité Champagne evaluates frost protection methods following three main axes: the efficiency, the profitability, and the environmental impact through a lifecycle assessment. This study will present the results on both passive and active protection following these three axes.

Bioclimatic shifts and land use options for Viticulture in Portugal

Land use, plays a relevant role in the climatic system. It endows means for agriculture practices thus contributing to the food supply. Since climate and land are closely intertwined through multiple interface processes, climate change may lead to significant impacts in land use. In this study, 1-km observational gridded datasets are used to assess changes in the Köppen–Geiger and Worldwide Bioclimatic (WBCS)

Spatiotemporal patterns of chemical attributes in Vitis vinifera L. cv. Cabernet Sauvignon vineyards in Central California

Spatial variability of vine productivity in winegrapes is important to characterise as both yield and quality are relevant for the production of different wine styles and products. The objectives were to understand how patterns of variability of Cabernet Sauvignon fruit composition changed over time and space, how these patterns could be characterised with indirect measurements, and how spatial patterns of the variation in fruit compositional attributes can aid in improving management. Prior to the 2017 vintage, 125 data vines were distributed across each of four vineyards in the Lodi American Viticultural Area (AVA) of California. Each data vine was sampled at commercial harvest in 2017, 2018, and 2019. Yield components and fruit composition were measured at harvest for each data vine, and maps of yield and fruit composition were produced for eight ‘objective measures of fruit quality’: total anthocyanins, polymeric tannins, quercetin glycosides, malic acid, yeast assimilable nitrogen, β-damascenone, C6 alcohols and aldehydes, and 3-isobutyl-2-methoxypyrazine. Patterns of variation in anthocyanins and phenolic compounds were found to be most stable over time. Given this relative stability, management decisions focused on fruit quality could be based on zonal descriptions of anthocyanins or phenolics to increase profitability in some vineyards. In each vineyard, dormant season pruning weights and soil cores were collected at each location, elevation and soil apparent electrical conductivity surveys were completed, and remotely sensed imagery was captured by fixed wing aircraft and two satellite platforms at major phenological stages. The data collected were used to develop relationships among biophysical data, soil, imagery, and fruit composition. The standardised and aggregated samples from four vineyards over three seasons were included in the estimation of ‘common variograms’ to assess how this technique could aid growers in producing geostatistically rigorous maps of fruit composition variability without cumbersome, single season sampling efforts.