 IVES 9 IVES Conference Series 9 Does bioprotection by adding yeasts present antioxydant properties?

Does bioprotection by adding yeasts present antioxydant properties?

Abstract

AIM: The bioprotection by adding yeasts is an emerging sulfur dioxide alternative. Sulfur dioxide is a chemical adjuvant used for its antiseptic, antioxidasic and antioxidant properties. Faced with the societal demand (Pérès et al., 2018) and considering the proven human risks associated with the total doses of sulfur dioxide (SO₂) present in food requirements (García‐Gavín et al., 2012), the reduction of this chemical input is undeniable. Bioprotection allows the control of microbial communities by occupying the grape must niche (Simonin et al., 2018; Windholtz et al., 2021), but no studies have been conducted on its antioxidant properties. Indeed, in must, reaction cascades can take place, bringing into play different compounds that can lead to its undesired browning under the action of polyphenols oxydases. SO₂ neutralizes these enzymes and regenerates the quinones. In the present study, bioprotection have been considered for its action on oxidation and on the availability of dissolved oxygen (O₂).

METHODS: In order to evaluate the potential impact of bioprotection on dissolved O₂ content, an experiment was conducted using semillon must. Three treatments were applicated: SO₂ at 50 mg/L, without SO₂ and bioprotection composed of two yeast species (Torulaspora delbrueckii and Metschnikowia pulcherrima in the same proportion) at 50 mg/L. O₂ concentration was monitored during pre-fermentation phase, using a FireStingO2 compact oximeter (pyroscience, Aix-La-Chappelle, Allemagne). The glutathione, a natural antioxydant compound, was quantified in the musts and wines.

RESULTS: Based on dissolved O₂ kinetics, the use of bioprotection led to a rapid consumption of O₂ and limited browning comparing to the control, without SO₂. The addition of SO_2,by neutralizing the polyphenol oxydases (Ough and Crowell, 1987), also limited the O₂ consumption. Bioprotection treatment allowed obtaining a significant higher concentration of glutathione in the finished wines than the control without SO₂, thus allowing an interesting additional protection during bottle aging.

CONCLUSIONS:

For the first time, this work highlighted the limitation of the white must oxidation by using non-Saccharomyces yeasts as bioprotection in a context of without SO₂. By decreasing the availability of dissolved oxygen, bioprotection by adding yeast would slowing down the oxidation cascades. Furthermore, preservation of glutathione by bioprotection allows additional protection in wines.

DOI:

Publication date: September 7, 2021

Issue: Macrowine 2021

Type: Article

Authors

Sara Windholtz, Claudia, Isabelle, Cécile

Unité de Recherche Œnologie, EA 4577, USC 1366 INRAE, Univ. Bordeaux, Bordeaux INP, ISVV, F33882 Villenave d’Ornon France , NIOI, Unité de Recherche Œnologie, EA 4577, USC 1366 INRAE, Univ. Bordeaux, Bordeaux INP, ISVV, F33882 Villenave d’Ornon France Pascaline, REDON, Unité de Recherche Œnologie, EA 4577, USC 1366 INRAE, Univ. Bordeaux, Bordeaux INP, ISVV, F33882 Villenave d’Ornon France, MASNEUF-POMAREDE, Unité de Recherche Œnologie, EA 4577, USC 1366 INRAE, Univ. Bordeaux, Bordeaux INP, ISVV, F33882 Villenave d’Ornon France ; Bordeaux Sciences Agro, Gradignan, France, THIBON, Unité de Recherche Œnologie, EA 4577, USC 1366 INRAE, Univ. Bordeaux, Bordeaux INP, ISVV, F33882 Villenave d’Ornon France

Contact the author

Keywords

bioprotection, oxygen consumption, gluthathion, white wine

Citation

Impact of pedoclimatical conditions on the precocity potential of vineyards in the canton of Geneva

Terroir studies are common nowadays but few have used precise pedoclimatic measures in order to evaluate the precocity potential. The objectives of this work were (i) to assess the effect of main terroir parameters (soil, climate and topography) influencing the phenological development of the vine, and (ii) to evaluate a geostatistic approach by using a high number of already existing plots (higher variability) to analyze the terroir parameters’ impact.

Volatile analysis of Botrytis contaminated grapes using headspace solid phase microextraction GC-MS

Grapes infected with grey mould due Botrytis cinerea are widespread in vineyards during certain growing conditions.

First step in the preparation of a soil map of the Protected Designation of Origin Valdepeñas (Central, Spain)

This work is a first step to make a map of vineyard soils. The characterization of the soils of the Protected Designation of Origin (D.P.O.) Valdepeñas will allow to group the studied profiles according to their physico-chemical characteristics and the concentrations of most relevant chemical elements. 90 soil profiles were analysed throughout the territory and the soils were sampled and described according to FAO (2006) and classified according to and Soil Taxonomy (2014). All samples were air dried, sieved and some physico-chemical parameters were determined following standard protocols. Also, major and trace elements were analysed by X-ray fluorescence. The statistically study was made using the SPSS program. Trend maps were made using the ArcGIS program. The studied soils have the following average properties: pH, 8.3; electrical conductivity, 0,20 dS/m (low); clay, 18.8% (medium) and CaCO3, 17.1% (high). In the study for the major elements. The major elements of these soils are Si, followed by Ca and Al, with an average content of 203.7 g/kg, 105.5 g/kg and 74.0 g/kg respectively. On the other hand, 27 trace elements have been studied. Of all of them, it can be highlighted the average values of Ba (361.8 mg/kg), Sr (129.3 mg/kg), Rb (83.4 mg/kg), V (74.2 mg/kg) and Ce (70.6 mg/kg). Ba, V and Ce values are higher and the values of Sr and Rb are lower to those found in the literature. The discriminant analysis shows a percentage of grouping of 91%. The content of chemical elements together with the physico-chemical characteristics allows grouping the soils in 4 group according to their order in the classification to Soil Taxonomy; due to the importance of the Calcisols in Castilla-La Mancha, it has been decided to establish them as their own group even if they do not appear in Soil Taxonomy classification.

Impact of seaweeds extracts applied to grapevine cv Tempranillo

Grapevine is one of the most-frequently phytosanitary treated crop systems. Consequently, restrictions have been applied by the European Commission on the number of pesticide treatments and the maximum quantity of copper fungicides allowed per year. Moreover, there is a need and an increasing demand for more ecological-sustainable agricultural products.
Seaweeds are currently used as fertilizers in viticulture, as they have been proven to be beneﬁcial in several ways related to growth and nutrition.

Can grapevine tolerance to bunch rot be directly induced by groundcover management?

Botrytis bunch rot occurrence is the most important limitation for the wine industry in humid environments. The effect of grapevine vegetative growth on bunch rot expression results from direct effects (cluster architecture, nitrogen status among others) and indirect ones (via microclimate). Previous studies of our group showed strong differences in bunch rot incidence between floor management treatments: cover crop (CC) vs weed-free strips under the trellis with herbicide (H). We observed that in some circumstances this reduction in bunch rot incidence occurred without major vine growth differences among treatments. The aim of the present study was to test the general hypothesis that other factors unrelated to grapevine vegetative expression could be more relevant to grapevine susceptibility to bunch rot.