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)


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.


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.”


Publication date: March 25, 2021

Issue: Terroir 2020

Type : Video


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

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

Contact the author


Postharvest dehydration, appassimento, Valpolicella, Amarone, gene expression


IVES Conference Series | Terroir 2020


Related articles…

Physiological and growth reaction of Shiraz/101-14 Mgt to row orientation and soil water status

Advanced knowledge on grapevine row orientation is required to improve establishment, management and outcomes of vineyards on terroirs with different environmental conditions (climate, soil, topography) and in view of a future change to more extreme climatic conditions. The purpose of this study was to determine the combined effect of row orientation, plant water status and ripeness level on the physiological and viticultural reaction of Shiraz/101-14 Mgt.

Effects of mechanical leafing and deficit irrigation on Cabernet Sauvignon grown in warm climate of California

San Joaquin Valley accounts for 40% of wine grape acreage and produces 70% of wine grape in California. Fruit quality is one of most important factors which impact the economical sustainability of farming wine grapes in this region. Due to the recent drought and expected labor cost increase, the wine industry is thrilled to understand how to improve fruit quality while maintaining the yield with less water and labor input. The present study aims to study the interactive effects of mechanical leafing and deficit irrigation on yield and berry compositions of Cabernet Sauvignon grown in warm climate of California.

The effects of cane girdling on berry texture properties and the concentration of some aroma compounds in three table grape cultivars

The marketability of the table grapes is highly influenced by the consumer demand; therefore the market value of the table grapes is mainly characterized by its berry size, colour, taste and texture. Girdling could cause accumulation of several components in plants above the ringing of the phloem including clusters and resulting improved maturity. The aim of the experiments was to examine the effect of girdling on berry texture characteristics and aroma concentration.

Application of a fluorescence-based method to evaluate the ripening process and quality of Pinot Blanc grape

The chemical composition of grape berries at harvest is one of the most important factors that should be considered to produce high quality wines. Among the different chemical classes which characterize the grape juice, the polyphenolic compound, such as flavonoids, contribute to the final taste and color of wines. Recently, an innovative non-destructive method, based on chlorophyll fluorescence, was developed to estimate the phenolic maturity of red grape varieties through the evaluation of anthocyanins accumulated in the berry skin. To date, only few data are available about the application of this method on white grape varieties.

Different yield regulation strategies in semi-minimal-pruned hedge (SMPH) and impact on bunch architecture

Yields in the novel viticulture training system Semi-Minimal-Pruned Hedge (SMPH) are generally higher compared to the traditional Vertical Shoot Positioning (VSP). Excessive yields have a negative impact on the vine and wine quality, which can result in substantial losses in yield in subsequent vintages (alternate bearing) or penalties in fruit quality. Therefore yield regulation is essential. The bunch architecture in SMPH differs from VSP. Generally there is a higher amount but smaller bunches with lower single berry weights in SMPH compared to VSP.