terclim by ICS banner
IVES 9 IVES Conference Series 9 PHENOTYPIC DIVERSITY AND BIO-PROTECTION CAPABILITY OF METSCHNIKOWIA SP. IN OENOLOGY

PHENOTYPIC DIVERSITY AND BIO-PROTECTION CAPABILITY OF METSCHNIKOWIA SP. IN OENOLOGY

Abstract

Nowadays, the trend is to reduce the use of chemical inputs in the food sector, including in oenology. One of the inputs widely used in the wine making process are sulfites, for its several properties: antimicrobial and antioxidiant. This use isn’t without consequences on consumer’s health and environment, it can lead for example to allergic reactions and pollution. To limit the addition of chemical inputs, microbial alternatives are used. It consists to inoculate in grape must, a micro-organism able to inhibit the growth of the negative indigenous flora during the phase before the fermentation and to guarantee the sensory qualities of wines. One of the specie the most used for its bio-protection capacity is the genus Metschnikowia. This project aims to study the phenotypical diversity in wine fermentative conditions and the diversity of bio-protector character of Metschnikowia sp.

To study the phenotypical diversity, 16 species of Metschnikowia within 50 strains have been selected depending their localization, their origins, and the species. These strains are used to ferment grape synthetical must, and the products of carbon central metabolism are analyzed by HPLC and the production of volatile molecules by GC-MS. In parallel, these strains are put in co-culture, with an acetic bacterium (Gluconobacter oxydans), known to lead to acetic souring, in commercial grape juice to study the interaction between yeast at 106cell/mL, and bacteria at 103cell/mL. Their growth is followed at day 0, 1, 2 and 7 through drop test on selective medium.

Similar to the fermentation aspects, the volatile profiles of the different strains were quite different, which corroborated the diversity of the Metschnikowia yeasts. The results of the drop test show an effect of bio-protection from the species Metschnikowia on the growth of G. oxydans. This work can underline both the potential of Metschnikowia yeast strains for inhibiting spoilage wine microorganisms and increasing aroma compounds.

DOI:

Publication date: February 9, 2024

Issue: OENO Macrowine 2023

Type: Poster

Authors

Angèle Thiriet², Pascale Fernandez-Valle¹, Cécile Grondin², Jean-Luc Legras1,2, Carole Camarasa¹, Audrey Bloem¹

1. UMR SPO, Univ Montpellier, INRAE, Institut Agro, 34060 Montpellier, France
2. CIRM Levures, UMR SPO, Montpellier, France

Contact the author*

Keywords

wine fermentation, bioprotection, Metschnikowia, diversity

Tags

IVES Conference Series | oeno macrowine 2023 | oeno-macrowine

Citation

Related articles…

TARTARIC STABILIZATION MAY AFFECT THE COLOR AND POLYPHENOLIC COMPOSITION OF TANNAT RED WINES FROM URUGUAY

Tartrate precipitation affects the properties of wines, due to the formation of crystals that cause turbidity, even after being bottled. The forced tartaric stabilization is carried out frequently for young wines, through various physicochemical procedures. The traditional treatment for tartaric stabilization is refrigeration, but it can have a negative effect on wine’s sensory properties, and particularly on the color of red wines. The aim of this study was to evaluate the effect of different tartaric stabilization options on the color and phenolic composition of Tannat red wines from Uruguay.

THE EFFECT OF COPPER ON THE PRODUCTION OF VARIETAL THIOLS DURING THE ALCOHOLIC FERMENTATION OF COLOMBARD AND GROS MANSENG GRAPE JUICES

Nowadays, the rapid growth of vineyards with organic practices and the use of copper as the only fun-gicide against downy mildew raises again the question of the effect of copper on varietal thiols in wine, especially 3-sulfanylhexan-1-ol (3SH) and its acetate (3SHA). A few decades ago, several works indicated that the use of copper in the vineyard had a negative effect on the content of varietal thiols in Sauvignon blanc wines [1, 2]. However, these studies only considered the concentration of the reduced form (RSH) of varietal thiols, without quantifying the oxidised ones. For this purpose, we proposed to monitor both reduced and oxidised forms of varietal thiols in wine under copper stress during alcoholic fermentation to have a more complete picture of the biological and chemical mechanisms.

INCREASING PINOT NOIR COLOUR DENSITY THROUGH SEQUENTIAL INOCULATION OF FLOCCULENT COMMERCIAL WINE YEAST SPECIES

Vitis vinifera L. cv. Pinot noir can be challenging to manage in the winery as its thin skins require careful handling to ensure sufficient extraction of wine colour to promote colour stability during ageing.1 Literature has shown that fermentation with flocculent yeasts can increase red wine colour density.2 As consumers prefer greater colour density in red wines,3 the development of tools to increase colour density would be useful for the wine industry. This research explored the impact of interspecies sequential inoculation and co-flocculation of commercial yeast on Pinot noir wine colour.

Overhead spray water treatment as a mitigation strategy for reducing vine stress and preserving grape quality during heatwaves

Changes in climate have been influencing the quality of wine grapes worldwide. The impact of extreme climate events over short periods is increasingly recognized as a serious risk to grape quality and yield quantity. In this study the mitigation effects of a pulsed water spray on vine canopy during heatwave events has been evaluated for maintaining vine condition during the growing season and grape quality. Vines of three varieties (Malbec, Bonarda, and Syrah) under drip irrigation in the UNCuyo experimental vineyard were treated with an overhead pulsed water spray.

FOURIER TRANSFORM INFRARED SPECTROSCOPY IN MONITORING THE WINE PRODUCTION

The complexity of the wine matrix makes the monitoring of the winemaking process crucial. Fourier Transform Infrared Spectroscopy (FTIR) along with chemometrics is considered an effective analytical tool combining good accuracy, robustness, high sample throughput, and “green character”. Portable and non-portable FTIR devices are already used by the wine industry for routine analysis. However, the analytical calibrations need to be enriched, and some others are still waiting to be thoroughly developed.