terclim by ICS banner
IVES 9 IVES Conference Series 9 WINE FERMENTATION METABOLITES PRODUCED BY TWO TORULASPORA DELBRUECKII STRAINS ISOLATED FROM OKANAGAN VALLEY, BC, CANADA VINEYARDS

WINE FERMENTATION METABOLITES PRODUCED BY TWO TORULASPORA DELBRUECKII STRAINS ISOLATED FROM OKANAGAN VALLEY, BC, CANADA VINEYARDS

Abstract

Wine aroma is influenced by various factors, from agricultural practices in the vineyard to the enological choices made by winemakers throughout the vinification process. Spontaneous fermentations have a characteristically deeper complexity of aromas when compared to fermentations that have been inoculated with Saccharomyces (S.) cerevisiae because of the diversity of microflora naturally present on grape skins. Non-Saccharomyces yeast are being extensively studied for their ability to positively contribute to wine aroma and flavour. These yeasts are known to liberate more bound volatile compounds present in grape must than S. cerevisiae through the enzymatic action of β-glucosidases and β-lyases1. Torulaspora (T.) delbrueckii is known to stand out among these nonconventional yeasts by increasing the content of esters, terpenes and thiols in wine fermentations, together with low production of acetic acid, hydrogen sulfide and acetaldehyde.

In a previous study using Pinot Noir grapes from the Okanagan Valley (BC, Canada)2, a collection of non-Saccharomyces yeasts was isolated from late-stage spontaneous lab fermentations. These yeasts were screened for their fermentative performance based on residual sugar, ethanol concentration and production of non-volatiles such as glycerol and acetic acid in single fermentations using Chardonnay juice. From these, two strains of T. delbrueckii were selected for further analysis. The aim of the present work was to examine oenological traits such as ethanol, sulfite, and copper sulfate resistance for the two T. delbrueckii Okanagan Valley strains, the T. delbrueckii reference strain CBS1146, the commercial T. delbrueckii strain Zymaflore Alpha and a control S. cerevisiae strain. These five strains were also used to perform single yeast fermentations in Muscat juice. Non-volatile compounds were quantified by HPLC/RID and analyzed by ANOVA with no significant differences in residual sugars, ethanol and glycerol production, while CBS1146 displayed lower acetic acid than the other 4 strains. Volatiles such as terpenes, primary alcohols and esters were also semi-quantified by SPME-GC/MS, followed by Partial Least Squares-Discriminant Analysis. Differences were observed among the strains in aroma compounds including limonene, γ-terpinene, α-terpineol, ocimene, phenylethyl alcohol and 2-phenethyl acetate. This work will add to developing research on T. delbrueckii from the perspective of BC and Canadian wines.

 

  1. Belda, I., Ruiz, J., Alastruey-Izquierdo, A., Navascues, E., Marquina, D., & Santos, A. (2016). Unraveling the enzymatic basis of wine “flavorome”: A phylo-functional study of wine related yeast species. Frontier in Microbiology, 7, 1–13. DOI: 10.3389/fmicb.2016.00012
  2. Cheng, E., Martiniuk, J. T., Hamilton, J., McCarthy, G., Castellarin, S. D., & Measday, V. (2020). Characterization of Sub-Regional Variation in Saccharomyces Populations and Grape Phenolic Composition in Pinot Noir Vineyards of a Canadian Wine Region. Frontiers in genetics, 11, 908. DOI: 10.3389/fgene.2020.00908

DOI:

Publication date: February 9, 2024

Issue: OENO Macrowine 2023

Type: Poster

Authors

Joana Pico1, Elia Castellanos1, Simone D. Castellarin1, Vivien Measday1

  1. Wine Research Centre, University of British Columbia

Contact the author*

Keywords

Non-Saccharomyces yeast, Wine aroma, Fermentation metabolites, Volatile compounds

Tags

IVES Conference Series | oeno macrowine 2023 | oeno-macrowine

Citation

Related articles…

SENSORY PROPERTIES IMPORTANT TO AUSTRALIAN FINE WINE CONSUMER SEGMENT PERCEPTION OF CHARDONNAY WINE COMPLEXITY AND PREFERENCE

Wine complexity is considered a multidimensional yet equivocal sensory percept. This project uncovered sensory attributes Australian Chardonnay wine consumers associate with Chardonnay wine complexity and correlations between expert and consumer perceived wine complexity and preference. A wine consumer test examined 6 Australian Chardonnay wines of three complexity levels designated low (LC1&2), medium (MC1&2), and high (HC1&2) by an expert panel (n = 8) using a benchtop sensory task. Consumers (n = 81) rated their perceived liking using a 9-point hedonic scale; wine complexity with a 5-point scale anchored “low”, “low-medium”, “medium”, “medium-high”, and “high” and lastly, profiled the wines using Rate-All-That-Apply (RATA). Psychographic segmentation with the Fine Wine Instrument (FWI) generated three segments; Wine Enthusiasts (WE n=29), Aspirants (ASP n=40) and No- Frills (NF n=12).
Read More

Grouping Vitis vinifera grapevine varieties based on their aromatic composition

Climate change is likely to impact wine typicity across the globe, raising concerns in wine regions historically renowned for the quality of their terroir1. Amongst several changes in viticultural practices, replacing some of the planting material (i.e. clones, rootstocks and cultivars) is thought to be one of the most promising potential levers to be used for adapting to climate change. But the change of cultivars also involves the issue of protecting the region’s wine typicity. In Bordeaux (France), extensive research has been conducted on identifying meridional varieties that could be good candidates to help guard against the effects of climate change2 while less research has been done concerning their impacts on Bordeaux wine typicity.

Read More

THE EFFECT OF COPPER ON THE PRODUCTION OF VARIETAL THIOLS DURING THE ALCOHOLIC FERMENTATION OF COLOMBARD AND GROS MANSENG GRAPE JUICES

Nowadays, the rapid growth of vineyards with organic practices and the use of copper as the only fun-gicide against downy mildew raises again the question of the effect of copper on varietal thiols in wine, especially 3-sulfanylhexan-1-ol (3SH) and its acetate (3SHA). A few decades ago, several works indicated that the use of copper in the vineyard had a negative effect on the content of varietal thiols in Sauvignon blanc wines [1, 2]. However, these studies only considered the concentration of the reduced form (RSH) of varietal thiols, without quantifying the oxidised ones. For this purpose, we proposed to monitor both reduced and oxidised forms of varietal thiols in wine under copper stress during alcoholic fermentation to have a more complete picture of the biological and chemical mechanisms.

Read More

NEW TREATMENTS FOR TEMPRANILLO WINES BY USING CABERNET SAUVIGNON VINE-SHOOTS AND MICRO-OXYGENATION

Toasted vine-shoots as enological additive represents a promising topic due to their significant effect on wine profile. However, the use of this new enological tool with SEGs varieties different than wine and combined with others winemaking technologies, such as micro-oxygenation (MOX), has not been studied so far, despite this combination could result in wine with high chemical and organoleptic quality.

Read More

‘TROPICAL’ POLYFUNCTIONAL THIOLS AND THEIR ROLE IN AUSTRALIAN RED WINES

Following anecdotal evidence of unwanted ‘tropical’ character in red wines resulting from vineyard interventions and a subsequent yeast trial observing higher ‘red fruit’ character correlated with higher thiol concentrations, the role of polyfunctional thiols in commercial Australian red wines was investigated.
First, trials into the known tropical thiol modulation technique of foliar applications of sulfur and urea were conducted in parallel on Chardonnay and Shiraz.1 The Chardonnay wines showed expected results with elevated concentrations of 3-sulfanylhexanol (3-SH) and 3-sulfanylhexyl acetate (3-SHA), whereas the Shiraz wines lacked 3-SHA. Furthermore, the Shiraz wines were described as ‘drain’ (known as ‘reductive’ aroma character) during sensory evaluation although they did not contain thiols traditionally associated with ‘reductive’ thiols (H2S, methanethiol etc.).

Read More