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…

The plantation frame as a measure of adaptation to climate change

The mechanization of vineyard work originally led to a reduction in planting densities due to the lack of machinery adapted to the vineyard. The current availability of specific machinery makes it possible to establish higher planting densities. In this work, three planting densities (1.40×0.80 m, 1.80×1 m and 2.20×1.20 m, corresponding to 8928, 5555 and 3787 plants/ha respectively) were studied with four varieties autochthonous of Galicia (northwestern Spain): Albariño and Treixadura (white), Sousón and Mencía (red). The vines were trained in a vertical shoot positioning system using a single Royat cordon, and pruned to spurs with two buds each. Agronomic data (yield, pruning wood weight, Ravaz index) and oenological data in must were collected. The higher planting density (1.40×0.80 m) had no significant effect on grape yield per vine in white varieties, although production per hectare was much higher due to the greater number of plants. In red varieties, this planting density resulted in a significantly lower production per vine, compensated by the greater number of plants. In addition, it significantly reduced the Brix degree in the must of the Albariño, Treixadura and Sousón varieties, and increased the total acidity in the latter two and Mencía. It also caused an increase in extractable and total anthocyanins and IPT in red grapes. The effects of high planting density on grapes are of great interest for the adaptation of varieties in the context of climate change. In the future, it could be advisable to modify the limits imposed by the appellations of origin on the planting density of these varieties in order to obtain more balanced wines.

Geospatial trends of bioclimatic indexes in the topographically complex region of Barolo DOCG

Barolo DOCG is an economically important wine producing region in Northwest Italy. It is a small region of approximately 70 km2 gross area. The topography is very complex with steep sloped hills ranging in elevation from below 200 m to 550 m. Barolo DOCG wine is made exclusively from the Nebbiolo grape. Bioclimatic indexes are often used in viticulture to gain a better understanding of broader climate trends which can be compared temporally and geographically. These indexes are also used for identifying potential phenological timing, growing region suitability, and potential risks associated with expected climatic changes. Understanding how topography influences bioclimatic indexes can help with understanding of mesoscale climate behaviour leading to improved decision making and risk management strategies. The average monthly maximum and minimum temperatures, the Cool Night Index, the Huglin Index, and the monthly diurnal range (from July to October) were calculated using data from 45 weather stations within a 40 km radius of the Barolo DOCG growing area between the years 1996 and 2019. Linear and multiple regression models were developed using independent variables (elevation, aspect, slope) extracted from a digital elevation model to identify significant relationships. Bioclimatic indexes were then kriged with external drift using independent variables that showed significant relationships with the bioclimatic index using a 100 m resolution grid. The maximum monthly temperatures and the Huglin Index showed consistent significant negative relationships with elevation in all years. The minimum monthly temperatures showed no relationship with elevation but in some months a small but significant relationship was observed with aspect. Due to the lack of a relationship between minimum monthly temperatures and elevation compared to the significant relationship between maximum monthly temperatures and elevation, monthly diurnal range had a negative relationship with elevation.

Legacy of land-cover changes on soil erosion and microbiology in Burgundian vineyards

Soils in vineyards are recognized as complex agrosystems whose characteristics reflect complex interactions between natural factors (lithology, climate, slope, biodiversity) and human activities. To date, most of the unknown lies in an incomplete understanding of soil ecosystems, and specifically in the microbial biodiversity even though soil microbiota is involved in many key functions, such as nutrient cycling and carbon sequestration. Soil biological properties are indicative of soil quality. Therefore, understanding how soil communities are related to soil ecosystem functioning is becoming an essential issue for soil strategy conservation. Here, we propose to assess the importance of land-cover history on the present-day microbiological and physico-chemical properties. The studied area was selected in the Burgundian vineyards (Pernand-Vergelesses, Burgundy, France) where land occupation has been reconstructed over the last 40 years. Soil samples were collected in five areas reflecting various land cover history (forest, vineyards, shifting from forest to vineyards). For each area, physico-chemical parameters (pH, C, N, P, grain size) were measured and DNA was extracted to characterize the abundance and diversity of microbial communities. The obtained results show significant differences in the five areas suggesting that present-day microbial molecular biomass and bacterial taxonomic is partly inherited from past land occupation. Over longer period of time, such study of land-uses legacies may help to better assess ecosystem recovery and the impact of management practices for a better soil quality and vineyards sustainability.

The combined effects of climate, soils, and deficit irrigation on yield and quality of Touriga Nacional under high atmospheric demand in the Douro Region

Global warming is one of the biggest environmental, social and economic threats in several viticultural regions. In the Douro Valley, changes are expected in the coming years, namely an increase in temperature and a decrease in precipitation. These changes are likely to have consequences for the production and quality of wine.
The aim of this study was to explore the effects of different soil characteristics combined with several deficit irrigation strategies, managed throughout ETc references and predawn leaf water potentials thresholds, on physiology, yield, and qualitative attributes on the Touriga Nacional variety under years of mild to severe water and heat stress.
The studies were conducted over seven years (2015 to 2021) in two plots of a commercial vineyard located at Quinta do Ataíde (Symington Family Estates) planted in 2011 and 2014 at 170 meters elevation, growing under three water regimes: non-irrigated (NI) and two deficit irrigation strategies (30% and 60% ETc) assessed weekly by Ψpd. The site has an annual rainfall below 500 mm, with high atmospheric demand. Climate data was collected from a weather station, located on site. Berry ripening was followed weekly for fruit analysis. At harvest, yield, vigour and pruning weight per vine were determined from 90 vines by treatment. Each season at veraison the NDVI Index was accessed by a drone. The soils physic-chemistry in the experimental blocs were analysed and grouped by SWHC. Delta C-13 analyses were also performed per treatment in two years.Irrigation had a positive effect on yield per vine, mostly due to an increase in berry and cluster weight, and fertility index through the years. A significant increase in sugar content, colour and phenols was observed with deficit irrigation in some years, but vine vigour related to soil characteristics had by far the greatest impact on quality.

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

[lwp_divi_breadcrumbs home_text="IVES" use_before_icon="on" before_icon="||divi||400" module_id="publication-ariane" _builder_version="4.19.4" _module_preset="default" module_text_align="center" module_font_size="16px" text_orientation="center"...