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…

Effect of vigour and number of clusters on eonological parameters and metabolic profile of Cabernet Sauvignon red wines

Vegetative growth and yield are reported to affect grape and wine quality. They can be controlled through different techniques linked to vine management. The objective of this research was to determine the effect of vine vigour and number of clusters per vine on physicochemical composition and phenolic profile of red wines. The experiment was carried out during two vegetative cycles, with cv. Cabernet Sauvignon grafted onto Paulsen 1103. Three vine vigour were defined, according to shoot weight at previous harvests, being low, medium and high. Five treatments of number of clusters were used for each vigour, with 15, 22, 29, 36, and 45 clusters per vine. Grapes from all treatments were harvested in the same day from Brix and total acidity criteria. Thirty days after bottling, classical analyzes and phenolic compounds were performed. As results, different responses were obtained from each vintage. In 2020, a dry season from veraison to harvest, grapes and wines obtained from low vigour treatment and 45 clusters per vine was the highest in sugar and alcohol content respectively, while grapes and wines from high vigour and 15 clusters presented the lowest sugar and alcohol content. Total anthocyanins were higher in treatment with low vigour and 15 clusters, while the lowest amounts were found in low vigour with 45 clusters, as well as medium and high vigour with 36 clusters per vine. Total tannins were higher in high vigour with 22 clusters and medium vigour with 29 clusters, while were lower in low vigour with 36 clusters. In 2021, a wet season at harvest, responses were different, and great variations were observed between treatments. As conclusions, yield and vine vigour had strong influence on grape and wine quality, promoting different enological potentials on which can be indicated/used for aging strategies of red and even rosé wines.

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.

Better understand the soil wet bulb formation with subsurface or aerial drip irrigation in viticulture

The gradual change in rainfall patterns experienced in the south of France vineyards, especially around the Mediterranean sea, means that the vines are increasingly subject to summer drought. The winegrowers developped the use of irrigation techniques to ensure the maintenance of competitive yields in the production of wines under Protected Geographical Indication label. In practice, drip irrigation pipes can be installed above the ground or buried into the soil as well as at different distances from the vine row. The objective of this study was to examine the profiles of the wet bulbs of the soil obtained from two drip irrigation systems : aerial drip located under the vine row and subsurface drip placed in the middle of the inter-row. This experiment took place over two consecutive seasons (2020-2021) on a 3.4 ha Viognier plot in the Mediterranean region (PGI Oc, France) on sandy clay soil. The annual rainfalls were less than 400 mm. Soil water content probes were installed at different depths (20 – 40 – 60 – 80 cm) and at different lateralities from the vine row (30 – 60 – 90 – 120 cm) to control the formation of the soil wet bulb during irrigation. The mapping and the analysis of the data allowed a better understanding and differentiation of the water percolation when irrigating with subsurface or aerial drip. For the same amount of water and without differences of vine water status, it is shown that in a subsurface drip irrigation situation, the size of the wet bulb formed is larger than in aerial drip irrigation system.

The impact of sustainable management regimes on amino acid profiles in grape juice, grape skin flavonoids, and hydroxycinnamic acids

One of the biggest challenges of agriculture today is maintaining food safety and food quality while providing ecosystem services such as biodiversity conservation, pest and disease control, ensuring water quality and supply, and climate regulation. Organic farming was shown to promote biodiversity and carbon sequestration, and is therefore seen as one possibility of environmentally friendly production. Consumers expect organically grown crops to be free from chemical pesticides and mineral fertilizers and often presume that the quality of organically grown crops is different or higher compared to conventionally grown crops. Integrated, organic, and biodynamic viticulture were compared in a replicated field trial in Geisenheim, Germany (Vitis vinifera L. cv. Riesling). Amino acid profiles in juice, grape skin flavonoids, and hydroxycinnamic acids were monitored over three consecutive seasons beginning 7 years after conversion to organic and biodynamic viticulture, respectively. In addition, parameters such as soil nutrient status, yield, vigor, canopy temperature, and water stress were monitored to draw conclusions on reasons for the observed changes. Results revealed that the different sustainable management regimes highly differed in their amino acid profiles in juice and also in their skin flavonol content, whereas differences in the flavanol and hydroxycinnamic acid content were less pronounced. It is very likely that differences in nutrient status and yield determined amino acid profiles in juice, although all three systems showed similar amounts of mineralized nitrogen in the soil. Canopy structure and temperature in the bunch zone did not differ among treatments and therefore cannot account for the observed differences in favonols. A different light exposure of the bunches in the respective systems due to differences in vigor together with differences in berry size and a different water status of the vines might rather be responsible for the increase in flavonol content under organic and biodynamic viticulture.

How can historical cultivars mitigate the effects of climate change?

IFV, INRAe and the national network “Partenaires de la Sélection Vigne” representing 37 organizations from the different wine regions, have been working increasingly closely over the last 2 decades towards the preservation of the French varietal patrimony. There are approximately 600 patrimonial varieties according to INRAe and SupAgro Montpellier experts, including ancient cultivars (400) and intravarietal crossbreeds obtained since the 19th century. In the context of a drastic reduction in such varieties from the mid 1980’s in favor of mainstream varieties, it was essential to carry out an inventory of old vines and vineyards. INRAe Vassal collection plays a key role here as it holds the largest diversity available, along with a rich bibliography and herbariums, offering us the opportunity to document and double check the identity of a cultivar, consolidating the expertise of ampelographers. The work is carried out in several stages, from verifying the existence of a variety in a small region, through to rehabilitation. During this session, the authors present the process that leads to the official registration of a variety. After this, IFV selection center takes over to initiate the process of selection and propagation. A specific focus within regions such as the Alps, Champagne and the South-West will provide details of the full procedure. Bia, Bouysselet, Chardonnay rose, Mecle and the aptly named Tardif, are some of the cultivars that have followed this procedure. Furthermore, a recent regulation established by INAO on “varieties of interest for adaptation purposes” might boost uptake by growers. Since 2006, 36 historical cultivars have been registered. Most of these have been neglected in the past due to late maturity, lack of sugar and high titratable acidity at harvest time. Such characteristics are today considered as positive qualities, not only in mitigation of the effects of climate change, but also as an opportunity for restoring diversity…