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IVES 9 IVES Conference Series 9 RED WINE AGING WITHOUT SO₂: WHAT IMPACT ON MICROBIAL COMMUNITY?

RED WINE AGING WITHOUT SO₂: WHAT IMPACT ON MICROBIAL COMMUNITY?

Abstract

Nowadays, the use of food preservatives is controversial, SO2 being no exception. Microbial communities have been particularly studied during the prefermentary and fermentation stages in a context of without added SO2. However, microbial risks associated with SO2 reduction or absence, particularly during the wine aging process, have so far been little studied.  The microbiological control of wine aging is a key issue for winemakers wishing to produce wines without added SO2. The aim of the present study is to evaluate the impact of different wine aging strategies according to the addition or not of SO2 on the microbiological population levels and diversity.

In 2021 and 2022, microbial community were monitored on merlot red wines during the wine aging process with different SO2 management and no SO2 addition. An experimental design (30L) was set up in triplicate and samples were collected from vatting to bottling to perform microbial analysis: population levels were monitored by plating on agar selective media for cultivable yeasts, acetic and lactic acid bacteria. From a subset of colonies obtained on solid medium, identifications at species level were made using the MALDI-TOF MS combining with a homemade database created by the laboratory.

In 2021, our results showed that without SO2, significant higher population levels of yeast and bacteria comparing with the sulphiting wines were present during the wine aging process. As expected, the higher species diversity was found at vatting. During the winemaking process, different species of lactic acid bacteria (10), acetic acid bacteria (3) and yeasts (8) were identified. Surprisingly, the effectiveness of SO2 addition at the end of MLF on the lactic acid bacteria showed contrasting results considering initial SO2 addition or not at vatting: population levels were significantly lower when SO2 was added only after malolactic fermentation. Our results regarding the impact of SO2 management during the winemaking process could provide opportunities for winemakers to reduce SO2 levels.  Furthermore, for the first time, microbial communities have been monitored throughout the winemaking process, in a reduced or without added SO2 context.

DOI:

Publication date: February 9, 2024

Issue: OENO Macrowine 2023

Type: Poster

Authors

Sara Windholtz1,2, Julie Maupeu3, Amelie Vallet Courbin3, Marine Lucas3, Valerian Duarte4, Anne Hubert5, Stéphane Becquet5, Emmanuel Vinsonneau4, Isabelle Masneuf Pomarède1,2

  1. Bordeaux, Bordeaux INP, INRAE, OENO, UMR 1366, ISVV, F-33140 Villenave d’Ornon, France
  2. Bordeaux Sciences Agro, Bordeaux INP, INRAE, OENO, UMR 1366, ISVV, F-33170 Gradignan, France
  3. Microflora-ADERA, Univ. Bordeaux, INRAE, Bordeaux INP, Bordeaux Sciences Agro, UMR 1366 OENOLOGIE, ISVV, F33882 Villenave d’Ornon, France
  4. Institut Français de la Vigne et du Vin, Blanquefort, France
  5. Syndicat des Vignerons Bio Nouvelle-Aquitaine, Montagne, France

Contact the author*

Keywords

wine without SO₂, microbial communities, MALDI-TOF MS, malolactic fermentation

Tags

IVES Conference Series | oeno macrowine 2023 | oeno-macrowine

Citation

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