Effect of Early Basal Leaf Removal on Phenolic and Volatile Composition and Sensory Properties of Aglianico Red Wines.

Debora Iorio,Luigi Tarricone,Mar Vilanova,Vito Michele Paradiso,Giuseppe Gambacorta

doi:10.3390/plants11050591

Abstract

The aim of this work was to study the influence of early basal leaf removal on Aglianico wines produced in the Apulia region (Italy). Three treatments were carried out, where 100% of fruit-zone leaves on the north (DN), south (DS) and on both sides of the canopy (DNS) were removed. A control (CT), where all basal leaves were retained, was also performed. Instrumental (HPLC-DAD-MS and GC-MS) and sensory analysis (QDA) were used to evaluate the treatment effect on the phenolic and volatile compositions and on the sensory descriptors of wines. DNS reached the highest amounts of phenolic compounds, showing a change in the phenolic pattern from flavonols and anthocyanins. Moreover, leaf removal influenced the levels of 37.8% of volatile compounds, quantified by increasing the concentration when early leaf removal was applied on the north side of the canopy (DN), with respect to the south (DS) and both sides (DNS). In the sensory analysis, Aglianico wines were defined by 16 sensory attributes with GM > 30%, where the highest values were reached for defoliation treatments vs. control. In conclusion, early leaf removal treatments allowed us to modulate the phenolic and volatile concentrations of Aglianico wines.

Highlights

In the last decade, new viticulture techniques have been developed around the world for cost-effective canopy management, with the aim of improving grape and wine quality
Early leaf removal led to wines of higher alcohol, and more total polyphenol index, whereas pH and titratable acidity and malic, tartaric, citric and acetic acids remained generally unaffected
Our results coincide with Diago et al [8], who reported that mechanical leaf removal was more effective in reducing yield, cluster weight and number of berries than manual leaf pulling, by affecting the fruit microclimate

Summary

Introduction

New viticulture techniques have been developed around the world for cost-effective canopy management, with the aim of improving grape and wine quality. Early leaf removal induced smaller and looser clusters that were less susceptible to Botrytis rot [2,4,5]. This practice determines specific transcriptional modifications, involving the ripening program and the flavonoid metabolism [6]. Early leaf removal could be applied by a defoliator machine for cost-effective yield control with improved grape [1] and wine composition [5] and aroma attributes [8]

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Results

Conclusion