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…

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.

Adapting the vineyard to climate change in warm climate regions with cultural practices

Since the 1980s global regime shift, grape growers have been steadily adapting to a changing climate. These adaptations have preserved the region-climate-cultivar rapports that have established the global trade of wine with lucrative economic benefits since the middle of 17th century. The advent of using fractions of crop and actual evapotranspiration replacement in vineyards with the use of supplemental irrigation has furthered the adaptation of wine grape cultivation. The shift in trellis systems, as well as pruning methods from positioned shoot systems to sprawling canopies, as well as adapting the bearing surface from head-trained, cane-pruned to cordon-trained, spur-pruned systems have also aided in the adaptation of grapevine to warmer temperatures. In warm climates, the use of shade cloth or over-head shade films not only have aided in arresting the damage of heat waves, but also identified opportunities to reduce the evapotranspiration from vineyards, reducing environmental footprint of vineyard. Our increase in knowledge on how best to understand the response of grapevine to climate change was aided with the identification of solar radiation exposure biomarker that is now used for phenotyping cultivars in their adaptability to harsh environments. Using fruit-based metrics such as sugar-flavonoid relationships were shown to be better indicators of losses in berry integrity associated with a warming climate, rather than solely focusing on region-climate-cultivar rapports. The resilience of wine grape was further enhanced by exploitation of rootstock × scion combinations that can resist untoward droughts and warm temperatures by making more resilient grapevine combinations. Our understanding of soil-plant-atmosphere continuum in the vineyard has increased within the last 50 years in such a manner that growers are able to use no-till systems with the aid of arbuscular mycorrhiza fungi inoculation with permanent cover cropping making the vineyard more resilient to droughts and heat waves. In premium wine grape regions viticulture has successfully adapted to a rapidly changing climate thus far, but berry based metrics are raising a concern that we may be approaching a tipping point.

Assessment of climate change impacts on water needs and growing cycle on grapevine in three DOs of NE Spain

This study assessed the suitability of grapevine growing in three DOs (Empordà, Pla de Bages and Penedès) of Catalonia (NE Spain) over the 21st century. For this purpose, an estimation of water needs and agroclimatic and phenological indicators was made. Climate change impacts were estimated at 1 km pixel resolution using temperature and precipitation projections from several general circulation models (GCM) and two climate change scenarios: RCP 4.5 (stabilization scenario) and RCP 8.5 (worst-case scenario). Potential crop evapotranspiration (following FAO procedure) and a daily water balance considering soil water holding capacity were used to estimate actual evapotranspiration of vines and, finally, water needs. Dynamics would be similar in the three DOs studied although the magnitude of impact differs. Water needs would be 2 and 3 times greater (ranging from 0 to more than 1500 m3/ha) than current water needs at both climate change scenarios. Moreover, blooming date would advance from 3 to 6 weeks, harvest date from 1 to 2.5 months, resulting in growing cycles from 10 to 80 days shorter. It should also be noted that frost risk would decrease from 6 to 76%, the number of days with temperatures above 30ºC during ripening would rise from 48 to 500% and tropical nights (minimum temperature >20ºC) at ripening would increase from 28 to 150%, depending on the scenario and the DOs. The impacts of climate change in the three DOs could result in significant limitations for grapevine cultivation and wine production if adaptive strategies are not applied. This result could serve as a basis for the design of specific and particular adaptation strategies to improve and maintain vineyards in the DOs studied and could be extrapolated to similar DOs and regions.

Mesoclimate impact on Tannat in the Atlantic terroir of Uruguay

The study of climate is relevant as an element conditioning the typicity of a product, its quality and sustainability over the years. The grapevine development and growth and the final grape and wine composition are closely related to temperature, while climate components vary at mesoscale according to topography and/or proximity to large bodies of water. The objective of this work is to assess the mesoclimate of the Atlantic region of Uruguay and to determine the effect of topography and the ocean on temperature and consequently on Tannat grapevine behavior.

Current climate change in the Oplenac wine-growing district (Serbia)

Serbian autochthonous vine varieties Smederevka (for white wines) and Prokupac (for rosé and red wines) are the primary representatives of typical characteristics of wines and terroir of numerous wine-growing areas in Serbia. In the past, these varieties were the leading vine varieties, however, as the result of globalization of winemaking and the trend of consumption of wines from widely prevalent vine varieties, they were replaced by introduced international varieties. Smederevka and Prokupac vine varieties are characterized by later time of grape ripening, and relative sensitivity to low temperatures. Climate conditions can be a restrictive factor for production of high-quality grapes and wine and for the spatial spreading of these varieties in hilly continental wine-growing areas.
This paper focuses on the spatial analysis of changes of main climate parameters, in particular, analysis of viticultural bioclimatic indices that were determined for the purposes of viticulture zoning of wine-growing areas in the period 1961-2010, and those same parameters determined for the current, that is, referential climate period (1988-2017). Results of the research, that is, analysis of climate changes indicate that the majority of examined climate parameters in the Oplenac wine-growing district improved from the perspective of Smederevka and Prokupac vine varieties. These studies of climate conditions indicate that changes of analyzed climate parameters, that is, bioclimatic indices will be favorable for cultivation of varieties with later grape ripening times and those more sensitive to low temperatures, such as the autochthonous vine varieties Smederevka and Prokupac, therefore, it is recommended to producers to more actively plant vineyards with these varieties in the territory of the Oplenac wine-growing district.