https://doi.org/10.17113/ftb.63.03.25.8804

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Impact of Fruit Zone Leaf Removal on Anthocyanin Stability in Wine During Bottle Ageing

Marina Pavlović^1*#, Zoran Zorić^1# Šime Marcelić¹, Maja Repajić², Name SurnamIva Šikuten^3,4 and Darko Preiner^3,4

¹University of Zadar, Department of Ecology, Agronomy and Aquaculture, Trg kneza Višeslava 9, 23000 Zadar, Croatia

²University of Zagreb Faculty of Food Technology and Biotechnology, Pierottijeva 6, 10000 Zagreb, Croatia

³University of Zagreb Faculty of Agriculture, Svetošimunska cesta 25, 10000 Zagreb, Croatia

⁴The Centre of Excellence for Biodiversity and Molecular Plant Breeding, Svetošimunska 25, 10000 Zagreb, Croatia

Copyright © 2025 This is a Diamond Open Access article published under CC-BY licence. Copyright remains with the authors, who grant third parties the unrestricted right to use, copy, distribute and reproduce the article as long as the original author(s) and source are acknowledged.

Article history:

Received: 31 July 2024

Accepted: 20 May 2025

Published online: 24 September 2025

Keywords:

red wine; anthocyanin stability; phenolic compounds; wine ageing; Mediterranean climate  

The content of this publication has not been approved by the United Nations and does not reflect the views of the United Nations or its officials or Member States.

Summary:

Research background. Anthocyanins, the most abundant pigments in red wine, play an important role in the visual aspect of wine sensory properties. However, due to their unstable nature, their ability to polymerise with tannins is important for colour stability. Their content varies with grapevine variety, growing conditions, viticultural and winemaking practices. Leaf removal, a common viticultural practice, enhances anthocyanin accumulation in red grapevines, and partial fruit zone leaf removal at different phenological stages can significantly influence the anthocyanin content of grapes and wine. This two-year study examined how two different times of fruit zone leaf removal at different phenological stages affect the initial anthocyanin content in wine and their stability during ageing in Merlot, Syrah and Cabernet Sauvignon wines grown in a Mediterranean climate.

Experimental approach. Partial leaf removal was applied during flowering and during vérasion and compared with untreated control. The wines obtained from all treatments and varieties were bottled two months after the end of fermentation, and then stored and matured under the cellar conditions for one year. To determine the influence of different times of leaf removal on the concentration of anthocyanins and their stability in the wine, the wines were analysed immediately after bottling and again after 6 and 12 months of storage. For the determination of all phenolic compounds, high-performance liquid chromatography (HPLC) was used.

Results and conclusions. Leaf removal treatments increased the concentration of anthocyanins in all three cultivars. The obtained results showed that malvidin-3-O-glucoside (Mal-3-Glc) was the most abundant individual anthocyanin, while the most unstable anthocyanin was petunidin-3-O-coumaroyl glucoside (Pet-3-Coum-Glc). Initial concentration of total anthocyanins in all wine samples was significantly affected by different conditions in the two years of study, but with a significant effect of the defoliation treatments. Anthocyanin concentration decreased during the ageing of the wine, and the degradation of anthocyanins ranged from 36 to 90 %. The stability of anthocyanins in wine was most influenced by ageing time, while year and treatment had no influence. The concentration of total phenolic acids increased during wine ageing, while the concentration of total flavonol glycosides (TFG) decreased in all wine samples except Merlot from 2016.

Novelty and scientific contribution. The results of this study contribute to a better understanding of the stability of increased concentrations of anthocyanins in wines during ageing obtained by the practice of grapevine leaf removal in the vineyard.

 
^#Both authors contributed equally