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…

Berry maturity effects on physic and chemical characteristics of traditional sparkling wines produced from Chardonnay and Sauvignon blanc grapes.

One of the consequences of global warming is the quick berry development giving rise to a disconnection between sugar accumulation and the formation of important quality minor compounds such as phenolics and volatile compounds being a huge challenge for the oenologist [1]. Thus, this phenomenon is forcing the search on strategies for maintaining the quality of wines despite this situation. One possibility is to make an early harvest with a low sugar concentration (18ºbrix) and advanced harvest for sparkling wine (20-21ºbrix) and afterwards to combine base wines properly and carry out the second fermentation trying to compensate the lack of secondary metabolites due to the quick berry development and higher alcohol degree of the second one, not adequate itself for sparkling wine. The aim of this study was to assess the chemical and physical characteristics, mainly volatile profile, and foaming properties of sparkling wines from grapes of Chardonnay and Sauvignon blanc.

The pyramidal organization of AOC in France: a process of identification and valorisation of terroirs

English version: Result of their history, some famous French wine countries such as Burgundy, Bordeaux or Alsace, have a hierarchical organization of their Appellations of Controlled Origin (AOC): AOC regional, communal, Premier Cru, Grand Cru.

Zoning, environment, and landscape: historic and perspective

Dans une approche globale, nous proposons la définition suivante du zonage : “représentation cartographique associée à une sectorisation du territoire en zones unitaires homogènes à partir de facteurs discriminants établis sur la base d’indicateurs quantifiables et d’avis d’experts”. La première application de cette méthode a porté sur la caractérisation du terroir en liaison avec les aspects qualitatifs des vins. Il est également possible d’envisager d’appliquer cette démarche dans les stratégies environnementales et paysagères liées aux approches territoriales et aux pratiques viticoles. Cette méthode peut servir de base dans la mise en œuvre des outils financiers associés aux mesures environnementales (CTE, aides spécifiques).

Identification of loci associated with specialised metabolites in Vitis vinifera

Secondary (or specialised) metabolites such as terpenes and phenolic compounds are produced by plants for various roles which include defence against pathogens and herbivores, protection against abiotic stress, and plant signalling. Additionally, these metabolites influence grapevine quality traits such as colour, aroma, taste, and nutritional value. However, the biosynthesis of these metabolites is often complex and controlled by multiple genes which in grapevine are predominantly uncharacterised.

Grafting, the most sustainable way to control phylloxera over 150 years

Just over 150 years ago, phylloxera, daktulosphaera vitifoliae, was introduced to europe, and particularly france, from north america via imports of american vitis plants. This aphid, with its complex biology and life cycle, has spread rapidly to most vineyards, causing rapid and lethal decline of v. Vinifera vines due to the primary and secondary damage it causes to the roots. In response to this pest, and given the economic importance of the french wine sector, professional representatives organised into ‘agricultural societies’, scientists and public authorities rallied together to identify the exact causes, seek solutions and try to stem the serious socio-economic crisis that ensued.