terclim by ICS banner
IVES 9 IVES Conference Series 9 Withering of the ‘Moscato giallo’ grapes under covered space

Withering of the ‘Moscato giallo’ grapes under covered space

Abstract

For the purpose of producing predicate wines in northern part of Croatia, grapes are traditionally left on the vine unpicked. However, grapes on the vine are exposed to unfavorable environmental conditions that affect rapid rotting and attacked by birds. To eliminate the mentioned risks, the grapes can be picked and placed in a protected space (loft, greenhouse, etc.) suitable for drying. This study presents the results of research on withering grapes of the ‘Moscato giallo’ variety in two tretment: sun drying (under covered terrace) and drying in the shade (loft). The following quality parameters were monitored: mass of grapes, sugar concentration, content of total acids, pH, content of organic acids. The total sugar content was determined refractometrically, the acid content was determined by neutralization with 0.1M NaOH and bromo-thymol as an indicator of pH change, the analysis of organic acids was carried out on an HPLC device. The research proved that in both treatment weight of the grapes and concentration of tartaric acid decreased during withering, while the concentration of sugar, malic acid, citric acid, and the content of total acids increased. Process of withering was shorter in sun drying treatment. Also, final concentration of sugar was higher in sun drying treatment. Final concentration of total acids, tartaric and malic acid was higher by drying in shade.

DOI:

Publication date: June 14, 2024

Issue: Open GPB 2024

Type: Poster

Authors

Domagoj Stupić1*, Laura Banović1, Iva Šikuten1, Petra Štambuk1, Ivana Tomaz1, Darko Preiner1, Zvjezdana Marković1, Željko Andabaka1, Edi Maletić1, Jasminka Karoglan Kontić1

1 University of Zagreb Faculty of Agriculture, Svetošimunska cesta 25, Zagreb, Croatia

Contact the author*

Keywords

withering, Moscato giallo, sun drying, shade drying, organic acids

Tags

IVES Conference Series | Open GPB | Open GPB 2024

Citation

Related articles…

Comparison of various storage conditions to preserve polyphenols in red-grape pomace

Red grape pomace, a waste from wine production, can be valorised by extracting polyphenols, high-added value compounds used in cosmetics or oenology. For use at an industrial level, using green extraction techniques, pomace need to be stored before being processed. The aim of this study is to test various storage conditions in order to maintain high level of polyphenols over 180 days, while keeping storage cost economically interesting. In a first step, different storage conditions (ambient temperature or cooled (4°C) temperature, anaerobic (saturation with N2) or aerobic conditions, and addition of sulphur dioxide (SO2)) were compared on small samples (1 kg) packed in plastic pockets. The quality of storage was assessed by following the optical density of the pomace extract at 280 nm (DO 280 expressed as mg/l eq gallic acid), which is an indication of the amount of remaining extractable polyphenols.

A look back at 20 years of exploring the future of the vines and wines sector

What if, in 25 years, most wines were dealcoholized and flavored ? What if vines were only cultivated to combat erosion, store carbon, and provide anthocyanins…? What if climate change completely changed the list of vine varieties cultivable for wine production in France? What if food stores had completely disappeared in favor of virtual platforms? And if… because the long-term future is not predetermined and therefore not knowable, because the future is open to several possibilities, because the future does not emerge from nothing but from the present which conceals heavy trends and weak signals, prospective approaches make it possible to consider the room for maneuver that actors have to promote the advent of a future, which we can hope to be chosen, at least in part.

DETERMINATION OF FREE AMINO ACIDS, AMINO ACID POTENTIAL AND PROTEASE ACTIVITY IN THE LEES AND STILL WINES OF CHAMPAGNE

Prior to winemaking, organic or mineral nitrogen compound concentrations are usually measured in the vineyard and in grape musts. These indicators facilitate vine cultivation decisions, usually through yield or vigor. During vinification, yeast and bacteria metabolize nitrogen compounds in the musts in order to generate biomass. After fermentation, the microorganisms rerelease a part of this nitrogen as soluble compounds into the wines. Another part remains bound in the lees and can be lost during racking. The must’s natural nitrogen quantities, additional supplements during fermentation, and lees contact management enhance the release of nitrogen compounds to the wines. During ageing these nitrogen compounds – primarily the amino acids – are implicated in the generation of odorous compounds such as heterocycles(1).

Variety “Rebula” (Vitis vinifera L.) determines the terroir Goriška brda “Collio” in Slovenia

A «terroir» is a group of vineyards from the same region, belonging to a specific appellation, and sharing the same type of soil, weather conditions, grapes and wine making savoir-faire, which contribute its specific personality to the wine. White wine variety «Rebula» or «Ribolla gialla» is a local and traditional variety, which is mentioned already in XIII. century like variety for tax paying and merchandise.

A viticultural perspective of Meso-scale atmospheric modelling in the Stellenbosch wine growing area, South Africa

La brise de mer et les facteurs climatiques qu’elle entraîne (accélération de la vitesse du vent au cours de l’après midi, augmentation de l’humidité et baisse de la temperature) sont d’un intérêt particulier pour la viticulture.