IVAS 2022 banner
IVES 9 IVES Conference Series 9 IVAS 9 IVAS 2022 9 Early fermentation aroma profiles of grape must produced by various non-Saccharomyces starters

Early fermentation aroma profiles of grape must produced by various non-Saccharomyces starters

Abstract

Saccharomyces cerevisiae is the most commonly used yeast species in winemaking. The recent research showed that non-Saccharomyces yeasts as fermentation starters show numerous beneficial features and can be utilized to reduce wine alcoholic strength, regulate acidity, serve as bioprotectants, and finally improve wine aromatic complexity. The majority of published studies on this topic investigated the influence of sequential or co-inoculations of non-Saccharomyces and S. cerevisiae yeasts on the aroma of final wine. Although some results are consistent with each other, there are many contrasting and contradicting outcomes, which most likely derived from the differences in grape juice composition, as well as due to various combinations and interactions of non-Saccharomyces and S. cerevisiae strains used in different studies. For these reasons, the actual contribution of non-Saccharomyces yeasts was often not completely distinguishable. The main premise of this study was that by investigating the production of volatile aroma compounds produced by non-Saccharomyces yeasts in the early phase of fermentation, prior to interaction with S. cerevisiae, a valuable insight from another perspective can be achieved about the particular effects they induce. Malvazija istarska (Vitis vinifera L.) white grape must was inoculated with the following non-Saccharomyces yeasts: Torulaspora delbrueckii, Metschnikowia
pulcherrima, Pichia kluyveri, Lachancea thermotolerans and Schizosaccharomyces pombe, while Saccharomyces cerevisiae was used as a control. The fermenting grape musts were subjected to headspace solid-phase microextraction and gas-chromatography-mass spectrometric analysis at the point just before S. cerevisiae inoculation, when alcohol level reached 1.5 – 2.5 vol. %. Each of the investigated non-Saccharomyces yeasts produced a
unique and distinctive aroma profile. The highest concentrations of linalool and β-damascenone were found in the must fermented by Pichia kluyveri and the lowest in the control S. cerevisiae must. The concentration of 2-phenylethanol produced by S. cerevisiae almost doubled those found in the musts of non-Saccharomyces starters. Ethyl propanoate differentiated well the investigated yeasts, with the highest concentration found in T.
delbrueckii must. This must also contained the highest concentrations of some other propanoates, including 2-phenethyl propanoate which turned out to be specific for this species. Particular non-Saccharomyces yeasts boosted the early synthesis of many important esters, such as ethyl hexanoate, ethyl octanoate and 2-phenethyl acetate, the main contributors to fruity and flowery notes of wine aroma. The obtained results showed that the potential of the investigated non-Saccharomyces yeasts to produce diverse wines is rather high. This study was funded by Croatian Science Foundation under the projects IP-2020-02-4551 and DOK-2021-02-5500.

DOI:

Publication date: June 24, 2022

Issue: IVAS 2022

Type: Poster

Authors

Delač Salopek Doris1, Horvat Ivana1, Hranilovic Ana2, Plavsa Tomislav1, Radeka Sanja1, Paskovic Igor1 and Lukic Igor1 

1Institute for Agriculture and Tourism
2Department of Wine Science, The University of Adelaide 

Contact the author

Keywords

non-Saccharomyces yeasts, sequential inoculation, SPME-GC-MS, volatile aroma compounds, esters

Tags

IVAS 2022 | IVES Conference Series

Citation

Related articles…

Effect of fertigation strategies to adapt PGI Côtes de Gascogne production to hot vintage

The development of fertigation could be a possible solution to adapt PGI Côtes de Gascogne (south-western France) wine production to climate change. The goal would be to limit the negative effects of water stress on yield performance expectation (around 15 tons per hectare) and to make the use of fertilizers more efficient. This study aimed to compare the effects of three strategies of water and minerals supply on grapes and wines qualities. Two fertigation practices were compared to a rainfed control which is the current standard of the local grape growing production. The fertilizers (nitrogen and potassium) were (i) fully brought by irrigation pipe during the season, (ii) partially brought by irrigation pipe and partially on the soil or (iii) fully brought on the soil at the beginning of the season for the non-irrigated control (local standard). The trial was run on cv. Colombard trained on spur pruned with vertical shoot positioning system on a sandy-silty-clay soil over the 2020 vintage which was particularly hot for the region. Moderate to strong water deficit appeared during the growing period of the berries and held on after veraison. Irrigation strategies allowed for maintaining grapevine without water deficit and being significantly different from the control water status. Grapevine with fully or partial fertigation strategies produced 25% more yield mainly due to the increase of the bunch weight. Also, the fully fertigation showed the best ratio between yield and maturity and brought 30% less of fertilizers (both nitrogen and potassium) than the two other strategies. Finally, the analysis of aromatic compounds in Colombard wines, varietal thiols family, showed the same level of concentrations for the 3 treatments, confirming that the yield performance did not impact the aromatic potential in this trial.

Drought affects vineyard soil microbiome: approach to select micro-organisms adapted to drought

Climate transition with frequent heat waves and long drought periods threatens grapevine productivity and wine quality in the Mediterranean regions. Microorganisms are known to contribute to plant fitness and to stimulate plant resilience against biotic and abiotic factors.
In this work, it was assessed the impact of long-term drought on soil microbiome associated to grapevine in open field in Alentejo, renowned Portuguese wine region.
Soil and plant tissues of drought tolerant Syrah cultivar exposed to three irrigation levels (100%- FI, 50%-DI ETc; rain-fed–NI) for 5 years were sampled for two years (2022-2023). Metabarcoding analysis of soil bacteria (16S V4 rRNA) and fungi (ITS sub-region) were integrated with soil physiochemical properties and leaves´ physiological data. Pre-dawn leaf water potential and stomatal conductance confirmed the imposed drought scenarios. Even though, α- and β-diversity of prokaryotic and eukaryotic microbial communities differed more by season than water availability, samples clustered according to soil water content and pH (p<0.05). Fungal communities show higher differences in the structure across treatments than bacteria. In 2023, 16 bacterial against 61 fungal ASVs were significatively different in abundance between NI and FI. Beijerinckiaceae, Bradyrhizobiaceae (Alphaproteobacteria) and Nocardioidaceae, Streptomycetaceae (Actinobacteria) families resulted to be significatively more abundant in NI, while Ascomycota, Basidyomicota and Mortierellomycota are the most important fungal phyla in NI. With culturomics data, this study aims to gather insights into how soil microbiome is remodelled under drought and contribute to select bacterial and fungal taxa with potential to mitigate drought stress in vineyards.

The role of terroir in tourism led amenity migration: contrasting effects in Tuscany and the Okanagan valley of British Columbia

Definitions of terroir elude consistent agreement. As defined geographical space the common denominators of its conceptualization include natural and cultural elements of life

Use of satellite in precision viticulture: the Franciacorta experience

Today, the concept of precision vine management (or site-specific viticulture) has a great relevance. It is based on the practice of a different management in relation to the different features of the crop site. In this way, all practices should be adapted to the land spatial variability and should be linked to the real needs of vines.

Understanding the genetic determinism of phenological and quality traits in ‘Corvina’ grape variety for selection of improved genotypes

Downy and powdery mildew are major issues in grapevine cultivation, requiring many phytosanitary treatments to ensure yield and quality. Climatic changes are also challenging grape cultivation