Effect of leaf removal and Shoot Topping on the aromatic composition of White wines

Abstract

[EN] The aim of this study was to evaluate the effect of canopy treatments on the aromatic composition and sensory qualities of Muscatel wines produced in the Valencia Region (Spain). The evaluation was conducted during 2008 and 2009 in an experimental field on vines in a vertical trellis system. The canopy treatments were made in the form of leaf removal and shoot topping using three different rootstocks (Couderc 3309, Paulsen 1103 and Ruggeri 140). The vine canopies of the control plants were given no treatment. Ripening was monitored by evaluating the content of soluble solids, total acidity and pH from veraison to harvest. 50 Kg grape samples were microvinificated, after which an evaluation was made of the aromatic composition and sensory attributes of the wines by gas chromatography. A sensory analysis was performed using a panel of wine expert tasters. The results of sugar accumulation in the grapes showed that leaf removal was the best canopy treatment in every plant rootstock. Lower yield was observed with both leaf removal and shoot topping. The highest concentration of aromatic compounds (acetates, alcohols, ethyl esters, fatty acids and monoterpenes) was found in wines made from the vines on Couderc 3309 rootstock who underwent to leaf removal and shoot topping. The wines from Couderc 3309 also obtained the highest scores in the sensory analysis. The wines from vines with leaf removal were the highest rated, while those from plants whose shoots had been topped were the lowest rated, regardless of the rootstock used.