IVAS 2022 banner
IVES 9 IVES Conference Series 9 IVAS 9 IVAS 2022 9 Unravelling the microbial community structure and aroma profile of Agiorgitiko wine under different inoculation schemes

Unravelling the microbial community structure and aroma profile of Agiorgitiko wine under different inoculation schemes

Abstract

Agiorgitiko (Vitis vinifera L. cv.) is the most widely cultivated indigenous red grape variety in Greece, known for the production of Protected Designation of Origin Nemea wines. The aim of the present study was to evaluate five different combinations of yeast starters, previously isolated from spontaneous alcoholic fermentation of the same grape variety, for their oenological potential in terms of fermentation predominance and capacity as well as aromatic contribution to Agiorgitiko wine production. Grapes from the Nemea region, crashed and pressed, were inoculated with different yeast species/strains in pure and mixed cultures.  In particular, wines were produced in duplicate with the addition of (A) Saccharomyces cerevisiae SFA1, (B) S. cerevisiae SFA2, (C) S. cerevisiae SFA3, (D) S. cerevisiae SFA3, Hanseniaspora opuntiae SFB1 and (E) S. cerevisiae SFA3, H. opuntiae SFB1, H. opuntiae SFB2 and Hanseniaspora uvarum SFC1. At specific time points during the alcoholic fermentation, amplicon-based metagenomics analysis was employed to unravel the microbial community structure at the genus level. In the end of the fermentation process oenological parameters including volatile acidity, residual sugars and ethanol were determined according to the OIV protocols while the volatile compounds produced were measured by GC/MS. Finally, all produced wines were evaluated  by quantitative descriptive analysis. As expected, Saccharomyces dominated the yeast/fungal microbiota of the A-C wine samples throughout fermentation, followed by Aspergillus, Cladosporium and Aureobasidium, mainly at the early fermentation stage. In D and E wine samples, although Hanseniaspora was the predominant genus in early fermentation, the relative abundance of Saccharomyces rapidly increased and dominated until the end of the fermentation. Compared to yeast/fungi, bacterial community was characterized by a quite higher diversity. Although similar genera were identified in all wine samples (A-E), e.g. Bacillus, Oenococcus, Lactococcus, Staphylococcus and Acinetobacter, their relative abundances varied depending on the sample and fermentation stage. As far as the volatile profile was concerned, the GC/MS analysis revealed that the use of different species/yeasts modified the flavor and aroma of the produced wines. More specifically, exceptional amounts of higher alcohols and medium-chain fatty acid esters (known for their floral and fruity contribution) were observed in the co-inoculated wines (D and E), resulting in a more distinct and intense aromas. According to sensory evaluation the co-inoculation with three different yeast species (wine sample E) significantly increased the aromatic typicity characterized by red fruits aromas. Understating the microbial community structure during the alcoholic fermentation could lead to higher quality wine product and constitute a strong tool to direct wine sensory traits

Acknowledgments

This research has been co-financed by the European Union and Greek national funds through the Operational Program Competitiveness, Entrepreneurship and Innovation, under the call “Greece – Israel Call for Proposals for Joint R&D Projects 2019” (project code: T10ΔΙΣ-00060).

DOI:

Publication date: June 23, 2022

Issue: IVAS 2022

Type: Article

Authors

Dimopoulou Maria¹, Kazou Maria², Drosou Fotini¹, Sellas Vassilis¹, Dourtoglu Vassilis¹ and Tsakalidou Effi²

¹Department of Wine, Vine, and Beverage Sciences, School of Food Science, University of West Attica, Athens, Greece
²Laboratory of Dairy Research, Department of Food Science and Human Nutrition, Agricultural University of Athens, Athens, Greece

Contact the author

Keywords

amplicon-based metagenomics analysis, wine aromas, regional yeast, Agiorgitiko

Tags

IVAS 2022 | IVES Conference Series

Citation

Related articles…

How distinctive are single vineyard Gewürztraminer musts and wines from Alto Adige (Italy) based on untargeted analysis, sensory profiling, and chemometric elaboration?

Vitis vinifera L. ‘Gewürztraminer’ is a historical grape variety of Alto Adige (Südtirol), Italy, which is widely grown in the area of Tramin an der Weinstraße, but is also grown globally. It produces highly aromatic wines that are strongly influenced by the terroir of the vineyard sites where they are grown. This study looked at musts and young wines from ‘Gewürztraminer’ grapes harvested in seven distinct vineyards near Tramin and then processed at Cantina di Termeno, minimizing winemaking protocol variability. Samples were profiled using bidimensional gas chromatography–time-of-flight mass spectrometry, liquid chromatography coupled to electrochemical detection, and near-IR spectrometry. The data were subjected to Principle Component Analysis and Hierarchical Clustering Analysis. Sensory discriminant testing was undertaken using the sorting method with a semi-trained panel, and the data were processed using Multidimensional Scaling. Seven must/wine pairs could be distinguished based on their untargeted volatilome profiles and on sensory evaluation. As expected, there were greater differences in the volatile compounds between the wines than between the musts. The wines from vineyards 4 and 5 were nonetheless quite homogenous in terms of chemical and sensory analyses, as were the wines from vineyards 1 and 3. For the phenolic profile, differences were noted between the musts and wines of vineyards 2, 3, and 4, but the musts from vineyards 5 and 7 were similar. Sensory analysis showed the wines from vineyards 6 and 7 to be distinct from the rest. These results reinforce that the composition of ‘Gewürztraminer’ musts and wines is strongly determined by vineyard site, even in a small geographic area with high variability of the terroir (soil and microclimate), and that these differences are apparent in the flavours and aromas of the finished wines. Further confirmation would require a larger sample of wines, preferably from several vintages.

Soil quality in Beaujolais vineyard. Importance of pedology and cultural practices

A pedological study was carried out from 2009 to 2017 in Beaujolais vineyard, to improve physical and chemical knowledge of soils. It was completed in 2016 and 2017 by the current study, dealing with microbial aspects, in order to build a reference frame for improved advice in soil management. Microbial biomass was measured on representative plots of the six most common soil types identified in Beaujolais and, for each soil type, on plots with different levels of the main impacting parameters: total organic carbon, pH, cation exchange capacity, extractable copper. A total of 59 soil samples were collected. Confirming the results of various trials carried out in Beaujolais over the past 20 years, the results of the present study showed that the soils were still alive, but exhibited a large variability of biological parameters, which appeared dependant on both pedological and anthropic factors. Therefore, a good interpretation of biological parameters and advice for vine growers must rely on a pedologically-based referential with differentiated main driving factors. For example, the control of pH is of primary importance in granitic soils and in no way organic matter addition can improve soil quality if pH is too low. Conversely, in calcareous soils, biological parameters are more directly affected by direct or indirect (cover crops for example) inputs of organic matter. The use of biological parameters, such as microbial biomass, is of great potential value to improve advice on agro-viticultural practices (soil management, fertilization, liming, etc.), basis of a sustainable wine production on fragile soils.

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.

Mapping and tracking canopy size with VitiCanopy

Understanding vineyard variability to target management strategies, apply inputs efficiently and deliver consistent grape quality to the winery is essential. However, despite inherent vineyard variability, the majority are managed as if they are uniform. VitiCanopy is a simple, grower-friendly tool for precision/digital viticulture that allows users to collect and interpret objective spatial information about vineyard performance. After four years of field and market research, an upgraded VitiCanopy has been created to achieve a more streamlined, technology-assisted vine monitoring tool that provides users with a set of superior new features, which could significantly improve the way users monitor their grapevines. These new features include:
• New user interface
• User authentication
• Batch analysis of multiple images
• Ease the learning curve through enhanced help features
• Reporting via the creation of colour maps that will allow users to assess the spatial differences in canopies within a vineyard.
Use-case examples are presented to demonstrate the quantification and mapping of vineyard variability through objective canopy measurements, ground-truthing of remotely sensed measurements, monitoring of crop conditions, implementation of disease and water management decisions as well as creating a history of each site to forecast quality. This intelligent tool allows users to manage grapevines and make informed management choices to achieve the desired production targets and remain profitable.

Adaptation to soil and climate through the choice of plant material

Choosing the rootstock, the scion variety and the training system best suited to the local soil and climate are the key elements for an economically sustainable production of wine. The choice of the rootstock/scion variety best adapted to the characteristics of the soil is essential but, by changing climatic conditions, ongoing climate change disrupts the fine-tuned local equilibrium. Higher temperatures induce shifts in developmental stages, with on the one hand increasing fears of spring frost damages and, on the other hand, ripening during the warmest periods in summer. Expected higher water demand and longer and more frequent drought events are also major concerns. The genetic control of the phenotypes, by genomic information but also by the epigenetic control of gene expression, offers a lot of opportunities for adapting the plant material to the future. For complex traits, genomic selection is also a promising method for predicting phenotypes. However, ecophysiological modelling is necessary to better anticipate the phenotypes in unexplored climatic conditions Genetic approaches applied on parameters of ecophysiological models rather than raw observed data are more than ever the basis for finding, or building, the ideal varieties of the future.