 IVES 9 IVES Conference Series 9 Effect of Saccharomyces species interaction on alcoholic fermentation behaviour and aromatic profile of Sauvignon blanc wine

Effect of Saccharomyces species interaction on alcoholic fermentation behaviour and aromatic profile of Sauvignon blanc wine

Abstract

Enhancing the sensory profile of wine by the use of different microorganism has been always a challenge in winemaking. The aim of our work was to evaluate the impact of different fermentation schemes by using mixed and pure cultures of different Saccharomyces species to Sauvignon blanc wine chemical composition and sensory profile. Sauvignon blanc must has been inoculated with mixed and pure cultures of S. pastorianus and S. cerevisiae. For the mixed fermentation schemes, one strain of S. pastorianus has been inoculated under different frequencies (99%, 95% , 90%, 80% and 70%) with two strains of S. cerevisiae. Totally 13 fermentations trials, 3 monocultures and 10 mixed cultures, were realised in triplicate. The fermentation kinetics has been controlled by density measurement and classic oenological analysis (residual sugars, total acidity, volatile acidity, malic acid degradation, glycerol production etc) were performed based on OIV protocols.The population dynamics was conducted by the specific interdelta PCR reaction of the Saccharomyces species in the beginning and in the end of the fermentation process. Volatile aromatic compounds such as esters, superior alcohols and thiols were evaluated by GC/MS analysis. Sensory assesement was carried out for all wines by trained panel. All fermentation trials lead to dryness and the fermentation lasted from 9 days to 13 days. The population dynamics analysis revealed that the S. cerevisiae strain was the most predominant in the end of the fermentation process in any inoculation ratio tested. The wines fermented with S. pastorianus, either in pure or mixed cultures, were characterised by significant lower acetic acid production and greater malic acid degradation compared to the wines fermented with S. cerevisiae strains. The aromatic profile of the produced wines was highly affected from the inoculation ratio while the effect of the S. cerevisiae used strain was less important. Our study based on different fermentation frequencies of mixed cultures of S. pastorianus and S. cerevisiae strains, revealed the impact of the inoculation ratio on the 30 tested volatiles compounds, correlated to Sauvignon blanc aromatic profile. The species of S. pastorianus starts to become an interesting candidate for co-inoculation with S. cerevisae strains, able to boost varietal aromas intensity.

DOI:

Publication date: September 3, 2021

Issue: Macrowine 2021

Type: Article

Authors

Maria Dimopoulou, Elli GOULIOTI, Vicky TROIANOU, Chrisavgi TOUMPEKi, Yves GOSSELIN, Etienne DORIGNAC, Nikolaos KONTOUDAKIS, Yorgos KOTSERIDIS

Department of Wine, Vine and Beverage Sciences, School of Food Science, University of West Attica, Greece, Laboratory of Oenology, Agricultural University of Athens, 75 Iera Odos, 11855 Athens, Greece, Innovino Research & Development, Meg. Alexandrou 21, Pallini 15351, Greece, Innovino Research & Development, Meg. Alexandrou 21, Pallini 15351, Greece, Fermentis 137 rue Gabriel Péri, 59703 Marcq en Baroeul, France, Fermentis 137 rue Gabriel Péri, 59703 Marcq en Baroeul, France, Laboratory of Oenology, Agricultural University of Athens, 75 Iera Odos, 11855 Athens, Greece, Laboratory of Oenology, Agricultural University of Athens, 75 Iera Odos, 11855 Athens, Greece

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Keywords

Saccharomyces bayanus, mixed cultures, species interaction, Sauvignon blanc, varietal aromas

Citation

Local adaptation tools to ensure the viticultural sustainability in a changing climate

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A better understanding of the climate effect on anthocyanin accumulation in grapes using a machine learning approach

The current climate changes are directly threatening the balance of the vineyard at harvest time. The maturation period of the grapes is shifted to the middle of the summer, at a time when radiation and air temperature are at their maximum. In this context, the implementation of corrective practices becomes problematic. Unfortunately, our knowledge of the climate effect on the quality of different grape varieties remains very incomplete to guide these choices. During the Innovine project, original experiments were carried out on Syrah to study the combined effects of normal or high air temperature and varying degrees of exposure of the berries to the sun. Berries subjected to these different conditions were sampled and analyzed throughout the maturation period. Several quality characteristics were determined, including anthocyanin content. The objective of the experiments was to investigate which climatic determinants were most important for anthocyanin accumulation in the berries. Temperature and irradiance data, observed over time with a very thin discretization step, are called functional data in statistics. We developed the procedure SpiceFP (Sparse and Structured Procedure to Identify Combined Effects of Functional Predictors) to explain the variations of a scalar response variable (a grape berry quality variable for example) by two or three functional predictors (as temperature and irradiance) in a context of joint influence of these predictors. Particular attention was paid to the interpretability of the results. Analysis of the data using SpiceFP identified a negative impact of morning combinations of low irradiance (lower than about 100 μmol m−2 s−1 or 45 μmol m−2 s−1 depending on the advanced-delayed state of the berries) and high temperature (higher than 25oC). A slight difference associated with overnight temperature occurred between these effects identified in the morning.

VineyardFACE: Investigation of a moderate (+20%) increase of ambient CO2 level on berry ripening dynamics and fruit composition

Climate change and rising atmospheric carbon dioxide concentration is a concern for agriculture, including viticulture. Studies on elevated carbon dioxide have already been on grapevines, mainly taking place in greenhouses using potted plants or using field grown vines under higher CO2 enrichment, i.e. >650 ppm. The VineyardFACE, located at Hochschule Geisenheim University, is an open field Free Air CO2 Enrichment (FACE) experimental set-up designed to study the effects of elevated carbon dioxide using field grown vines (Vitis vinifera L. cvs. Riesling and Cabernet Sauvignon). As the carbon dioxide fumigation started in 2014, the long term effects of elevated carbon dioxide treatment can be investigated on berry ripening parameters and fruit metabolic composition.
The present study aims to investigate the effect on fruit composition under a moderate increase (+20%; eCO2) of carbon dioxide concentration, as predicted for 2050 on both Riesling and Cabernet Sauvignon. Berry composition was determined for primary (sugars, organic acids, amino acids) and secondary metabolites (anthocyanins). Special focus was given on monitoring of berry diameter and ripening rates throughout three growing seasons. Compared to previous results of the early adaptative phase of the vines [1], our results show little effect of eCO2 treatment on primary metabolites composition in berries. However, total anthocyanins concentration in berry skin was lower for eCO2 treatment in 2020, although the ratio between anthocyanins derivatives did not differ.
[1] Wohlfahrt Y., Tittmann S., Schmidt D., Rauhut D., Honermeier B., Stoll M. (2020) The effect of elevated CO2 on berry development and bunch structure of Vitis vinifera L. cvs. Riesling and Cabernet Sauvignon. Applied Science Basel 10: 2486

‘Cabernet Sauvignon’ (Vitis vinifera L.) berry skin flavonol and anthocyanin composition is affected by trellis systems and applied water amounts

Trellis systems are selected in wine grape vineyards to mainly maximize vineyard yield and maintain berry quality. This study was conducted in 2020 and 2021 to evaluate six commonly utilized trellis systems including a vertical shoot positioning (VSP), two relaxed VSPs (VSP60 and VSP80), a single high wire (SH), a high quadrilateral (HQ), and a guyot (GY), combined with three levels of irrigation regimes based on different crop evapotranspiration (ETc) replacements, including a 25% ETc, 50% ETc, and 100% ETc. The results indicated SH yielded the most fruits and accumulated the most total soluble solids (TSS) at harvest in 2020, however, it showed the lowest TSS in the second season. In 2020, SH and HQ showed higher concentrations in most of the anthocyanin derivatives compared to the VSPs. Similar comparisons were noticed in 2021 as well. SH and HQ also accumulated more flavonols in both years compared to other trellis systems. Overall, this study provides information on the efficacy of trellis systems on grapevine yield and berry flavonoid accumulation in a currently warming climate.

VINIoT: Precision viticulture service for SMEs based on IoT sensors network

The main innovation in the VINIoT service is the joint use of two technologies that are currently used separately: vineyard monitoring using multispectral imaging and deployed terrain sensors. One part of the system is based on the development of artificial intelligence algorithms that are feed on the images of the multispectral camera and IoT sensors, high-level information on water stress, grape ripening status and the presence of diseases. In order to obtain algorithms to determine the state of ripening of the grapes and avoid losing information due to the diversity of the grape berries, it was decided to work along the first year 2020 at berry scale in the laboratory, during the second year at the cluster scale and on the last year at plot scale. Different varieties of white and red grapes were used; in the case of Galicia we worked with the white grape variety Treixadura and the red variety Mencía. During the 2020 and 2021 campaigns, multispectral images were taken in the visible and infrared range of: 1) sets of 100 grapes classifying them by means of densimetric baths, 2) individual bunches. The images taken with the laboratory analysis of the ripening stage were correlated. Technological maturity, pH, probable degree, malic acid content, tartaric acid content and parameters for assessing phenolic maturity, IPT, anthocyanin content were determined. It has been calculated for each single image the mean value of each spectral band (only taking into account the pixels of interest) and a correlation study of these values with laboratory data has been carried out. These studies are still provisional and it will be necessary to continue with them, jointly with the training of the machine learning algorithms. Processed data will allow to determine the sensitivity of the multispectral images and select bands of interest in maturation.