Terroir 2020 banner
IVES 9 IVES Conference Series 9 Towards the definition of a terroir of grape dehydration for the production of ‘Passito’ wines in Valpolicella (Italy)

Towards the definition of a terroir of grape dehydration for the production of ‘Passito’ wines in Valpolicella (Italy)

Abstract

Aim: The aim of this study was to investigate the relationship between the molecular response of grapes during postharvest dehydration and the specific environment of two naturally ventilated rooms (called ‘fruttai’), located in two different sites in Valpolicella. 

Methods and Results: Grapes of Corvina and Corvinone were harvested in the same field in 2018 and placed in two different ‘fruttai’, equipped with stations for constant registration of internal temperature and humidity. The expression of genes encoding terpenoid synthase, stilbene synthase, pectin metylesterase and laccase, previously reported to be highly dependent on the environmental condition during dehydration, were analyzed. The results showed that the four genes increased their expression during withering in both genotypes, with clear differences in the pattern of expression associated to the two ‘fruttai’, and sometimes highlighting a genotype-per-environment interaction.

Conclusions: 

This experimental plan revealed important relationships between the natural climatic conditions of the site where the dehydration takes place, and the molecular response of dehydrating berries.

Significance and Impact of the Study:  The postharvest dehydration of grape berries is a traditional method used to produce ‘passito’ wines such as Amarone and Recioto in the Valpolicella area of Italy. This technique allows the concentration of sugars and other solutes in the berry and promotes the synthesis of metabolites and aroma compounds unique to these wines. These dynamic changes are dependent on environmental parameters such as temperature and relative humidity. In Valpolicella, the dehydration process is made in naturally ventilated rooms called ‘fruttai’, where the internal environmental conditions are strictly dependent on the external meso-climate. This study improved our understanding of the influence of the geographic location of the ‘fruttaio’ on the expression of quality biomarkers of dehydrated grapes. In this context, the molecular analytical approach represents a powerful tool to explore the ongoing metabolisms of grapes dehydrated in different conditions and may allow to highlight and preserve the typicity of the wine by linking its quality to a “postharvest dehydration terroir.”

DOI:

Publication date: March 25, 2021

Issue: Terroir 2020

Type : Video

Authors

G.B. Tornielli1*, M. Bona1, E. D’Incà1, S. Zenoni1

1Department of Biotechnology, University of Verona, Verona, Italy

Contact the author

Keywords

Postharvest dehydration, appassimento, Valpolicella, Amarone, gene expression

Tags

IVES Conference Series | Terroir 2020

Citation

Related articles…

An operational model for capturing grape ripening dynamics to support harvest decisions

Grape ripening is a critical phenophase during which many metabolites driving wine quality are accumulated in berries. Major changes in berry composition include a rapid increase in sugar and a decrease in malic acid content and concentration. Its duration is highly variable depending on grapevine variety, climatic parameters, soil type and management practices.

Exploring the genomic diversity of yeast involved in spontaneous fermentation. from studies to select autochthonous strains of different italian’s wineries to extensive phylogenetic survey about the italians’ population of s. cerevisiae

Modern winemakers must ensure effective alcoholic fermentation without losing the intrinsic biodiversity of the different oenological contexts. In this sense, the population of saccharomyces cerevisiae characteristic of wineries that traditionally do not use selected yeasts can represent an interesting reservoir of biodiversity.

Influence of grapes origin and yeast strain on aroma profile of corvina and corvinone dry passito wines

Valpolicella is a wine region characterized by a wide use of the technology of grape drying for the production of two red passito wines, recognized as PDOs, “Recioto della Valpolicella” and the most famous “Amarone della Valpolicella”. Geographical origin of the grapes can influence wine composition by grape chemical composition yeast behaviour during fermentation. This study investigates the impact of different commercial yeast strains on aroma profiles of wines produced with withered grapes of different origins. In addition, the influence of spontaneous fermentation is also considered. METHODS: Experimental red wines were produced with a standard winemaking protocol with withered Corvina and Corvinone grapes obtained from two different geographical areas within the Valpolicella region. Fermentations were carried out with four different commercial yeasts plus a spontaneous fermentation. Wines were analysed by means of SPE- and SPME-GC-MS techniques and sensory analysis (sorting task).

From grapevines to extreme environments … and back?

I performed my PhD in grapevine physiology under the supervision of Dr. H. Medrano, standing in the vineyards from pre-dawn to sunrise during many hot, wet and sunny days with my colleagues J.M.E. and J.B. I also spent many days and nights facing ticks year-round working in Mediterranean macchias with J.Gu. and M.M. Later I was able to supervise PhD students on grapevines – like A.P. and M.T. – and on Mediterranean vegetation – like J.Gal. With the incorporation to the group of M.R.-C. ‘the puzzle’ was completed and, combining the aforementioned studies, we could conclude (more than 20 years ago) things like: (1) stomatal conductance is the best proxy for ‘water stress’ in studies on photosynthesis; (2) steady-state chlorophyll fluorescence retrieves photosynthesis under saturating light; (3) photoinhibition is not a major photosynthetic limitation under water stress; (4) mesophyll conductance instead is; and (5) mesophyll conductance is a major driver of leaf water use efficiency.

Can soil nitrate explain polyphenol and anthocyanin content in vineyard with similar available soil water regime? 

Nitrogen (N) is quite important nutrient in grapevine development and must quality, but under Mediterranean climatic conditions, available soil water (ASW) during grapevine development can also influence vigour and must quality. The aim was to determine the influence of soil nitrate (NO3-) availability on N foliar, yield, and must quality in vineyards with similar available water holding capacity (AWC). For this purpose, four cv. Tempranillo (Vitis vinifera L.) vineyards were selected. All of them are placed in Uruñuela municipality (La Rioja, Spain), separated less than 2.5 km and in a slope <1 %, in soils with similar soil chemistry properties and with similar rooting depth (ranging between 105 cm and 110 cm).