WAC 2022 banner
IVES 9 IVES Conference Series 9 WAC 9 WAC 2022 9 3 - WAC - Posters 9 Bio-acidification of wines by Lachancea thermotolerans

Bio-acidification of wines by Lachancea thermotolerans

Abstract

Insufficient acidity in grapes from warm climates/vintages is commonly corrected through addition of tartaric acid during vinification, and less so with other organic acids. An alternative approach involves bio-acidification with the yeast Lachancea thermotolerans (LT) via lactic acid production during fermentation. Our work first elucidated the genetic (~200) and phenotypic (~100) diversity of LT strains, and then tested the performance of their subset in co-cultures with Saccharomyces cerevisiae (SC). In pure and mixed cultures alike, the modulation of acidity and other compositional parameters of wines depended on the LT strain, with either comparable or significant acidification relative to the SC control. An LT strain with exceptional bio-acidifying properties was selected, capable of lowering wine pH by ~0.5 units, and further characterised across a range of oenological conditions.

Our follow-up study aimed to i) compare the profiles of bio-acidified LT wines and acid-adjusted SC wines, and ii) evaluate the use of LT wines as blending components. For this purpose, high sugar/pH Merlot grapes were fermented with a sequential culture of LT and SC, and an SC monoculture. The aliquots of the SC control (pH 4) were acidified with either tartaric or lactic acid to the pH of the LT wine (pH 3.6), and the initial wines also blended in three proportions (1:3, 1:1, 3:1). Chemical analysis revealed major differences in a range of chemical parameters of wines (e.g. ethanol content, acidity parameters, volatile compounds, amino acids).  The compositional modulations were reflected in the sensory profiles of wines, as confirmed via ‘Rate-All-That-Apply’ evaluation by wine experts (n=30). Sensory profiles of the bio-acidified LT wine and the lactic acid-adjusted SC wine were similar, and contrasting to the tartaric acid-adjusted SC wine. Despite an identical initial matrix, lactic acid-adjusted SC wine had higher ‘red fruit’ flavour, and lower ‘hotness’, ‘bitterness’ and ‘body’ relative to tartaric acid-adjusted wine. This was driven by differences in ‘acidity’ perception, affected by titratable acidity (rather than pH) of wines. An inhibition of Brettanomyces bruxellensis growth was also observed in the bio-acidified LT wine and the lactic-acid adjusted SC wine. The profiles of blends were modulated depending on the proportion of the bio-acidified wine, thus highlighting the potential of this approach to boost ‘freshness’ and differentiate wine styles.

DOI:

Publication date: June 27, 2022

Issue: WAC 2022

Type: Article

Authors

Ana, Hranilovic, Marina Bely, Isabelle Masneuf-Pomarede, Joana Coulon, Warren Albertin, Vladimir Jiranek

Presenting author

Ana, Hranilovic – Department of Wine Science, The University of Adelaide, Australia

Université of Bordeaux, UR œnologie, EA 4577, USC 1366 INRAE, Bordeaux INP, ISVV, Villenave d’Ornon, France | Université of Bordeaux, UR œnologie, EA 4577, USC 1366 INRAE, Bordeaux INP, ISVV, Villenave d’Ornon, France | BioLaffort, Floirac, France | Université of Bordeaux, UR œnologie, EA 4577, USC 1366 INRAE, Bordeaux INP, ISVV, Villenave d’Ornon, France | Department of Wine Science, The University of Adelaide, Australia,

Contact the author

Keywords

non-Saccharomyces yeasts – Lachancea thermotolerans – wine acidification – volatile composition – RATA sensory profiling

Tags

IVES Conference Series | WAC 2022

Citation

Related articles…

Terroir in Slovak viticulture area

Terroir method has been used for assessment of growing site in the world for years. In Slovakia actually regionalisation is used as the similar method which does not cover all the elements of wine quality evaluation however.

NEW METHOD FOR THE QUANTIFICATION OF CONDENSED TANNINS AND OTHER WINE PHENOLIC COMPOUNDS USING THE AUTOMATED BIOSYSTEMS SPICA ANALIZER

Wine phenolic compounds are important secondary metabolites in enology due to their antioxidant and nutraceutical properties, and their role in the development of color, taste, and protection of wine from oxidation and spoilage. Tannins are valuable phenolic compounds that contribute significantly to these wine properties, especially in mouthfeel characteristics; however, tannin determination remains a significant challenge, with manual and time-consuming methods or complex methodologies. The purpose of this study is to propose a novel method for quantifying condensed tannins in finished wine products.

Identification and biological properties of new resveratrol derivatives formed in red wine

Resveratrol is a well-known wine constituent with a wide range of activities. In wines, resveratrol can be oxidized to form various derivatives including oligomers [1]. In this study, resveratrol derivative transformation in hydroalcoholic solution was investigated by oxidative coupling using metals. De novo resveratrol derivatives were synthetized and analysed by NMR and MS experiments

Grapevine yield-gap: identification of environmental limitations by soil and climate zoning in Languedoc-Roussillon region (south of France)

Grapevine yield has been historically overlooked, assuming a strong trade-off between grape yield and wine quality. At present, menaced by climate change, many vineyards in Southern France are far from the quality label threshold, becoming grapevine yield-gaps a major subject of concern. Although yield-gaps are well studied in arable crops, we know very little about grapevine yield-gaps. In the present study, we analysed the environmental component of grapevine yield-gaps linked to climate and soil resources in the Languedoc Roussillon. We used SAFRAN data and IGP Pays d’Oc wine yields from 2010 to 2018. We selected climate and soil indicators proving to have a significant effect on average wine yield-gaps at the municipality scale. The most significant factors of grapevine yield were the Soil Available Water Capacity; followed by the Huglin Index and the Climatic Dryness Index. The Days of Frost; the Soil pH; and the Very Hot Days were also significant. Then, we clustered geographical zones presenting similar indicators, facilitating the identification of resources yield-gaps. We discussed the number of zones with the experts of IGP Pays d’Oc label, obtaining 7 zones with similar limitations for grapevine yield. Finally, we analysed the main resources causing yield-gaps and the grapevine varieties planted on each zone. Mapping grapevine resource yield-gaps are the first stage for understanding grapevine yield-gaps at the regional scale.

Exploring microbial interactions between Saccharomyces cerevisiae and non-Saccharomyces yeast starters in vinification

Winemaking is a complex microbial process involving the co-existence and interactions of various microorganisms [1].