Effects of leaf removal on aromatic precursor dynamics during maturation of Ribolla Gialla grapes (Vitis viniferaL.)

Sabrina Voce,Giovanni Bigot,Davide Mosetti,Giulia Pizzamiglio,Andrea Lonardi,Paolo Sivilotti,Piergiorgio Comuzzo

doi:10.1051/bioconf/20191303008

Abstract

Leaf removal is a viticultural practice applied in order to improve fruit-zone microclimate and berry quality. The aim of this trial was to evaluate the effect of post-flowering leaf removal on maturation and biosynthesis of terpenes and and C13-norisoprenoids in Ribolla Gialla grapes. In the seasons 2015 and 2016, basic maturation parameters were nearly unaffected by leaf removal. Contrarily, in the second season, 2016, one week before harvest, the concentration of several aroma compounds was significantly improved by leaf removal. In conclusion, the trial here showed that leaf removal improves the concentration of aroma compounds in the grapes, but the selection of the date of harvest is more crucial in order to maintain them during vinification.

Highlights

Aroma compounds in grapes are found as glycosylated precursors and, during alcoholic fermentation, they are released, contributing to the varietal aroma of wine
The two season were characterized by different trends in terms of temperature and rainfall
In the season 2015, from June on, temperatures were higher compared to the historical values and two peaks were registered at the last ten days of August and at between 10th and 20th of September

Summary

Introduction

Aroma compounds in grapes are found as glycosylated precursors and, during alcoholic fermentation, they are released, contributing to the varietal aroma of wine. They are produced during berry ripening by different biosynthetic pathways [1,2,3] and their concentration depends on a combination of different factors. Ribolla Gialla is an autochthonous grape variety widespread in Friuli Venezia Giulia (North East Italy) and in western Slovenia. Because of the limited interest that such varieties attracted in the past, little information is available in the international literature databases [14,15]

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Results