Macrowine 2021
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 SO2,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

Related articles…

Modeling the suitability of Pinot Noir in Oregon’s Willamette Valley in a changing climate

Air temperature is the key driver of grapevine phenology and a significant environmental factor impacting yield and quality for a winegrape growing region. In this study the optimal downscaled CMIP5 ensemble for computing thegrowing season average temperature (GST) viticulture climate classification index was determined to spatially compute on a decadal basis predictions of the GST climate index and the grapevine sugar ripeness (GSR) model for Pinot Noir throughout the Willamette Valley (WV) American Viticultural Area (AVA). Forecasts for average temperature and a 220 g/L target sugar concentration level were computed using daily Localized Constructed Analogs (LOCA) downscaled CMIP5 historic and Representative Concentration Pathways (RCP) future climate projections of minimum and maximum daily temperature. We explore spatiotemporal trends of the GST climate classification index and Pinot Noir specific applications of the GSR phenology model for the WV AVA. Spatiotemporal computations of the GST climate index and Pinot Noir specific applications of the GSR model enable the opportunity to explore relationships between their computed values with one intent being to provide updated GST ranges that better align with current temperature-based modeling understanding of Pinot Noir grapevine phenology and the viticultural application of LOCA CMIP5 climate projections for the WV AVA. The Pinot Noir specific applications of the GSR model or the GST index with updated bounds indicate that the percent of the WV AVA area suitable for Pinot Noir production is currently at or near its peak value in the upper 80s to lower 90s of this century.

Assessing the relationship between cordon strangulation, dieback, and fungal trunk disease symptom expression

Grapevine trunk diseases including Eutypa dieback are a major factor in the decline of vineyards and may lead to loss of productivity, reduced income, and premature reworking or replanting. Several studies have yielded results indicating that vines may be more likely to express symptoms of vascular disease if their health is already compromised by stress. In Australia and many other wine-growing regions it is a common practice for canes to be wrapped tightly around the cordon wire during the establishment of permanent cordon arms. It is likely that this practice may have a negative effect on health and longevity, as older cordons that have been trained in this manner often display signs of decay and dieback, with the wire often visibly embedded within the wood of the cordon. It is possible that adopting a training method which avoids constriction of the vasculature of the cordon may help to limit the onset of vascular disease symptom expression. A survey was conducted during the spring of two consecutive growing seasons on vineyards in South Australia displaying symptoms of Eutypa lata infection when symptomless shoots were 50–100 cm long. Vines were assessed as follows: (i) the proportion of cordon exhibiting dieback was rated using a 0–100% scale; (ii) the proportion of canopy exhibiting foliar symptoms of Eutypa dieback was rated using a 0–100% scale; (iii) the severity of strangulation was rated using a 0–4 point scale. Images were also taken of each vine for the purpose of measuring plant area index (PAI) using the VitiCanopy App. The goal of the survey was to determine if and to what extent any correlation exists between severity of strangulation and cordon dieback, in addition to Eutypa dieback foliar symptom expression.

Phenological characterization of a wide range of Vitis Vinifera varieties

In order to study the impact of climate change on Bordeaux grape varieties and to assess the adaptation capacities of candidates to the grape varieties of this wine region to the new climatic conditions, an experimental block design composed of 52 grape varieties was set up in 2009 at the INRAE Bordeaux Aquitaine center. Among the many parameters studied, the three main phenological stages of the vine (budburst, flowering and veraison) have been closely monitored since 2012. Observations for each year, stage and variety were carried out on four independent replicates. Precocity indices have been calculated from the data obtained over the 2012-2021 period (Barbeau et al. 1998). This work allowed to group the phenological behaviour of the grapevine varieties, not only based on the timing of the subsequent developmental stages, but also on the overall precocity of the cycle and the total length of the cycle between budburst and veraison. Results regarding the variability observed among the different grape varieties for these phenological stages are presented as heat maps.

Climate change impacts on Douro Region viticulture and adaptation measures

Climate has a significant impact in the success of any agricultural system, with a direct influence on the crops suitability to a given region, interfering on yield and quality and also with the economic sustainability of the productive activity. In the Douro Demarcated Region (RDD), as in most regions of the Mediterranean climate, the scarce precipitation (33% has less than 600 mm per year), and your high variability, associated with high rates of evapotranspiration during the summer, is usually one of the fundamental factors that limit the grapevine development, as well as the production and quality of the harvest. Thus, facing the scenario in temperature changes for the next decades (1.5-2.5°C) and confirming the predictions of precipitation decreases and/or great variability in the occurrence of heat waves and intense rainfall, the consequences for slope stability in mountain viticulture and sustainability of all operations involved, are risks to be taken into account. In this way, a deepest and sustained knowledge regarding the adaptation measures to adverse environmental conditions is of a crucial importance, enabling a more efficient adaptation of plant growth conditions and the optimization of production and quality of the grapevines. The development of this work, carried out in two commercial vineyards, one located in Soutelo do Douro, São João da Pesqueira, Cima Corgo sub-region, and another located in Numão, Vila Nova de Foz Côa, Douro Superior sub-region, it seeks to establish a relationship between climatic elements and physiological, productive and qualitative parameters, as well as to evaluate the effectiveness of adaptation measures, including different types of deficit irrigation (2002-2019) and the application of shading nets (2019-2020) in the physiological, viticultural and oenological behavior in the Touriga Nacional and Moscatel Galego Branco varieties, respectively. The results showed that the application of deficit irrigation allowed to significantly reduce the impact of the adverse weather conditions at key moments in the development of the grapevine, particularly in the period immediately before veráison and maturation, reducing the negative effects on the physiological processes and productivity, without compromise the must quality parameters. On the other hand, the application of shading nets significantly reduced de leaves temperature, allowing to increase the water potential, stomatal conductance and photosynthetic rate of grapes, which was reflected in the yield increase in the 2nd year of the study. For the maturation indicators, higher levels of total acidity, malic acid and assimilable nitrogen were obtained. The last measure presents a huge potential, being essential to carry out more years of trials to obtain stronger conclusions in terms of production parameters, but also in characteristics as important as the grape ripening components and the organoleptic characteristics of wines.

Impact of climate change on the viticultural climate of the Protected Designation of Origin “Jumilla” (SE Spain)

Protected Designation of Origin “Jumilla” (PDO Jumilla) is located in the Spanish provinces of Albacete and Murcia, in the South-eastern part of the Iberian Peninsula, where most of the models predict a severe impact of climate change in next decades. PDO Jumilla covers an area of 247,054 hectares, of which more than 22,000 hectares