 IVES 9 IVES Conference Series 9 Impact of environmental conditions in vscs production during wine fermentation by Saccharomyces cerevisiae

Impact of environmental conditions in vscs production during wine fermentation by Saccharomyces cerevisiae

Abstract

The aroma of wine is one of the most important determinants of quality as it strongly influences the consumer’s acceptance or rejection. Among the thousands of molecules comprising the wine aroma, sulfur-containing compounds can be considered as a “double-edged sword”: some of them, deriving from varietal precursors provide fruity pleasant aromas, while other ones, produced by yeast metabolism are related to “unpleasant” aromas. The negative impact and their low limit threshold make these volatile sulfur compounds (VSCs) an essential object of study to control the quality of the wine. To date, the chemical and metabolism mechanisms involved in the formation of VSC during fermentation remain poorly elucidated. Furthermore, the incidence of environmental or technological factors that may interact with yeast metabolism on the VSCs production has not been comprehensively studied. In this context, this project aimed to further investigate the formation of VSCs during S. cerevisiae wine fermentation, assessing the relative contribution of yeast metabolism and chemical conversions to VSCs production and studying the modulation of these productions by environmental (nitrogen resource composition and availability, vitamin concentration) or technological (SO2 addition) parameters. Fermentations were carried out using different conditions (YAN, pantothenic acid concentrations, methionine, and cysteine availability) with 4 S. cerevisiae strains and the production of 18 VACs was measured by GC-MS to elucidated how the variation of these parameters changes final concentration. As expected the addition of methionine incremented the final production of methional derivated compounds but didn’t affect the rest of the compounds. The addition of cysteine increment the production of the esters (methyl thioacetate and ethyl thioacetate) without changing the rest concentrations of other compounds. We also found out that an increment in pantothenic acid, as the addition of methionine, can promote the production of methional-derived compounds. With these data, we could be able to reduced total VSC production during fermentation.

DOI:

Publication date: September 3, 2021

Issue: Macrowine 2021

Type: Article

Authors

Rafael Jimenez Lorenzo, Pascale Brial, Cristian Picou, Marc Perez, Audrey Bloem, Carole Camarasa

UMR SPO, INRA, Université Montpellier, SupAgro

Contact the author

Keywords

saccharomyces cerevisiae, vsc, fermentation, yan, gc-ms

Citation

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Projected changes in vine phenology of two varieties with different thermal requirements cultivated in La Mancha DO (Spain) under climate change scenarios

The aim of this work was to analyze the phenology variability of Tempranillo and Chardonnay cultivars, related to the climatic characteristics in La Mancha Designation of Origin, and their potential changes under climate change scenarios. Phenological dates referred to budbreak, flowering, veraison and harvest were analyzed for the period 2000-2019. The weather conditions at daily time scale, recorded during the same period, were also evaluated. The thermal requirements to reach each of these phenological stages were calculated and expressed as the GDD accumulated from DOY=60. Changes in phenology were projected by 2050 and 2070 taking into account those values and the projected temperatures and precipitation, simulated under two Representative Concentration Pathway (RCP) scenarios –RCP4.5 and RCP8.5– using an ensemble of models. The average phenological dates during the period under study were, April 16th ± 6.6 days and April 5th ± 6.0 days for budbreak, May 31st ± 6.0 days and May 27th ± 5.3 days for flowering, July 26th ± 5.6 days and July 25th ± 5.8 days for veraison, and Ago 23rd ± 10.8 days and Ago 17th ± 9.0 days for harvest, respectively, for Tempranillo and Chardonnay. The projected changes in temperature imply an average change in the maximum growing season (April-August) temperatures of 1.2 and 1.9°C by 2050, and 1.6 and 2.6°C by 2070, under the RCP4.5 and RCP8.5 scenarios, respectively. A reduction in precipitation is predicted, which vary between 15% for 2050 under RCP4.5 scenario and up to 30% by 2070 under RCP8.5. The advance of the phenological dates for 2050, could be of 6, 7, 7, and 8 days for Tempranillo and 4, 6, 6 and 9 days for Chardonnay, respectively for budbreak, flowering, veraison and harvest under the RCP4.5 scenario. Under the RCP8.5 emission scenario, the advance could be up to 30% higher.