 IVES 9 IVES Conference Series 9 Evaluation of intrinsic grape berry and cluster traits for postharvest withering kinetics prediction

Evaluation of intrinsic grape berry and cluster traits for postharvest withering kinetics prediction

Abstract

To make some particular wine styles (e.g., Amarone), grapes are harvested and stored in dehydrating rooms before vinification, in a process called withering. This practice increases the concentration of sugars and other solutes and encourages the accumulation of unique aroma compounds in berries. Previous investigations evidenced that the kinetics of grape dehydration highly affects the quality of the produced wine. Along with the well-known effects of the environmental conditions, the cluster and berry morphology have an important role in the determination of the grape water loss rate. However, the relative contribution of each cluster/berry physical trait to the dehydration rate and the possibility to predict the latter parameter in advance, are poorly studied aspects. The aim of this work was to investigate the effect of several grape physical/morphological parameters on the withering kinetic rate, individuating potential predictors of the grapes behavior during postharvest dehydration. Four red wine grape cultivars, Corvina, Corvinone, Cabernet-Sauvignon and Cavrara, were harvested at commercial ripening and their cluster compactness, berry surface area to volume ratio, skin thickness and skin waxes quantity were measured. Furthermore, a novel rapid dehydration test in a controlled forcing environment (50 °C; 400 mbar; 24 h) was applied on grape clusters to assess their intrinsic tendency to lose water. The grapes were then withered for 77 days, under controlled environmental conditions simulating the commercial process, and the dehydration kinetic rates were obtained. Multivariate and correlation analyses were employed to search and score the relation between each measured parameter and the withering kinetic rate. The parameters which were pointed out as good predictors of the grapes water loss attitude were the skin thickness, berry surface area to volume ratio and cluster compactness. However, intra-cultivar analyses performed on Corvina and Corvinone separately have not identified parameters with significant correlations to the withering kinetic rate, likely because of the very low variability observed among accessions of the same cultivar.

DOI:

Publication date: September 7, 2021

Issue: Macrowine 2021

Type: Article

Authors

Ron Shmuleviz

Department of Biotechnology, University of Verona, Via della Pieve 70, 37029 – San Floriano, San Pietro in Cariano – VR, Italy., Giovanni Battista TORNIELLI, Department of Biotechnology, University of Verona, Via della Pieve 70, 37029 – San Floriano, San Pietro in Cariano – VR, Italy.

Contact the author

Keywords

wine grapes, dehydration kinetics, withering, fruit morphology, amarone

Citation

Anthocyanin profile is differentially affected by high temperature, elevated CO₂ and water deficit in Tempranillo (Vitis vinifera L.) clones

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Climate projections over France wine-growing region and its potential impact on phenology

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Photoselective shade films affect grapevine berry secondary metabolism and wine composition

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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.

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