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 variability and change on grape yield in Italy

Viticulture is entangled with weather and climate. Therefore, areas currently suitable for grape production can be challenged by climate change. Winegrowers in Italy already experiences the effect of climate change, especially in the form of warmer growing season, more frequent drought periods, and increased frequency of weather extremes.
The aim of this study is to investigate the impact of climate variability and change on grape yield in Italy to provide winegrowers the information needed to make their business more sustainable and resilient to climate change. We computed a specific range of bioclimatic indices, selected by the International Organisation of Vine and Wine (OIV), and correlated them to grape yield data. We have worked in collaboration with some wine consortiums in northern and central Italy, which provided grape yield data for our analysis.
Using climate variables from the E-OBS dataset we investigate how the bioclimatic indices changed in the past, and the impact of this change on grape productivity in the study areas. The climate impact on productivity is also investigated by using high-resolution convection-permitting models (CPMs – 2.2 horizontal resolution), with the purpose of estimating productivity in future emission scenarios. The CPMs are likely the best available option for this kind of impact studies since they allow a better representation of small-scale processes and features, explicitly resolve deep convection, and show an improved representation of extremes. In our study, we also compare CPMs with regional climate models (RCMs – 12 km horizontal resolution) to assess the added value of high-resolution models for impact studies. Further development of our study will lead to assessing the future suitability for vine cultivation and could lead to the construction of a statistical model for future projection of grape yield.

Biodiversity in the vineyard agroecosystem: exploring systemic approaches

Biodiversity conservation and restoration are essential for guarantee the provision of ecosystem services associated to vineyard agroecosystem such as climate regulation trough carbon sequestration and control of pests and diseases. Most of published research dealing with the complexity of the vineyard agroecosystems emphasizes the necessity of innovative approaches, including the integration of information at different temporal and spatial scales and development of systemic analysis based on modelling. A biodiversity survey was conducted in the Franciacorta wine-growing area (Lombardy, Italy), one of the most important Italian wine-growing regions for sparkling wine production, considering a portion of the territory of 112 ha. The area was divided into several Environmental Units (EUs), defined as a whole vineyard or portion of vineyard homogenous in terms of four agronomic characteristics: planting year, planting density, cultivar, and training system. In each EU a set of compartments was identified and characterised by specific variables. The compartments are meteorology, morphology (altitude, slope, aspect, row orientation, and solar irradiance), ecological infrastructures and management. The landscape surrounding EU was also characterised in terms of land-use in a buffer zone of 500 m. For each component a specific methodology was identified and applied. Different statistical approaches were used to evaluate the method to integrate the information related to different compartments within the EU and related to the buffer zone. These approaches were also preliminarily evaluated for their ability to describe the contribution of biodiversity and landscape components to ecosystem services. This methodological exploration provides useful indication for the development of a fully systemic approach to structural and functional biodiversity in vineyard agroecosystems, contributing to promote a multifunctional perspective for the all wine-growing sector.

Anthocyanin profile is differentially affected by high temperature, elevated CO2 and water deficit in Tempranillo (Vitis vinifera L.) clones

Anthocyanin potential of grape berries is an important quality factor in wine production. Anthocyanin concentration and profile differ among varieties but it also depends on the environmental conditions, which are expected to be greatly modified by climate change in the future. These modifications may significantly modify the biochemical composition of berries at harvest, and thus wine typicity. Among the diverse approaches proposed to reduce the potential negative effects that climate change may have on grape quality, genetic diversity among clones can represent a source of potential candidates to select better adapted plant material for future climatic conditions. The effects of individual and combined factors associated to climate change (increase of temperature, rise of air CO2 concentration and water deficit) on the anthocyanin profile of different clones of Tempranillo that differ in the length of their reproductive cycle were studied. The aim was to highlight those clones more adapted to maintain specific Tempranillo typicity in the future. Fruit-bearing cuttings were grown in controlled conditions under two temperatures (ambient temperature versus ambient temperature + 4ºC), two CO2 levels (400 ppm versus 700 ppm) and two water regimes (well-watered versus water deficit), both in combination or independently, in order to simulate future climate change scenarios. Elevated temperature increased anthocyanin acylation, whereas elevated CO2 and water deficit favoured the accumulation of malvidin derivatives, as well as the acylation and tri-hydroxylation level of anthocyanins. Although the changes in anthocyanin profile observed followed a common pattern among clones, such impact of environmental conditions was especially noticeable in one of the most widely distributed Tempranillo clones, the accession RJ43.

Revealing the Barossa zone sub-divisions through sensory and chemical analysis of Shiraz wine

The Barossa zone is arguably one of the most well-recognised wine producing regions in Australia and internationally; known mainly for the production of its distinct Shiraz wines. However, within the broad Barossa geographical delimitation, a variation in terroir can be perceived and is expressed as sensorial and chemical profile differences between wines. This study aimed to explore the sub-division classification across the Barossa region using chemical and sensory measurements. Shiraz grapes from 4 different vintages and different vineyards across the Barossa (2018, n = 69; 2019, n = 72; 2020, n = 79; 2021, n = 64) were harvested and made using a standardised small lot winemaking procedure. The analysis involved a sensory descriptive analysis with a highly trained panel and chemical measurement including basic chemistry (e.g. pH, TA, alcohol content, total SO2), phenolic composition, volatile compounds, metals, proline, and polysaccharides. The datasets were combined and analysed through an unsupervised, clustering analysis. Firstly, each vintage was considered separately to investigate any vintage to vintage variation. The datasets were then combined and analysed as a whole. The number of sub-divisions based on the measurements were identified and characterised with their sensory and chemical profile and some consistencies were seen between the vintages. Preliminary analysis of the sensory results showed that in most vintages, two major groups could be identified characterised with one group showing a fruit-forward profile and another displaying savoury and cooked vegetables characters. The exploration of distinct profiles arising from the Barossa wine producing region will provide producers with valuable information about the regional potential of their wine assisting with tools to increase their target market and reputation. This study will also provide a robust and comprehensive basis to determine the distinctive terroir characteristics which exist within the Barossa wine producing region.

Phenological characterization of a wide range of Vitis Vinifera varieties

In order to study the impact of climate change on Bordeaux grape varieties and to assess the adaptation capacities of candidates to the grape varieties of this wine region to the new climatic conditions, an experimental block design composed of 52 grape varieties was set up in 2009 at the INRAE Bordeaux Aquitaine center. Among the many parameters studied, the three main phenological stages of the vine (budburst, flowering and veraison) have been closely monitored since 2012. Observations for each year, stage and variety were carried out on four independent replicates. Precocity indices have been calculated from the data obtained over the 2012-2021 period (Barbeau et al. 1998). This work allowed to group the phenological behaviour of the grapevine varieties, not only based on the timing of the subsequent developmental stages, but also on the overall precocity of the cycle and the total length of the cycle between budburst and veraison. Results regarding the variability observed among the different grape varieties for these phenological stages are presented as heat maps.