Effect of varying leaf-fruit ratios on sensory attributes of Malbec wines from SHW-trellised vineyards

AHUMADA, GASTON EMANUEL; FANZONE, MARTIN; GONZALEZ, CARINA VERONICA; CATANIA, ANIBAL; GIORDANO, CARLA VALERIA; PIRRONE, MIGUEL; BELMONTE, MARCELO

Ginebra

Congreso; 42nd World Congress of Vine & Wine (OIV Meeting); 2019

OIV

Argentina is the fifth world wineproducer being Malbec its emblematic variety. Mendoza is the most important Argentineanwine region as it has the greatest implanted area and the most awarded wines.Vineyards for wine production are mainly conducted in the VSP trellis system. Thesingle-high wire (SHW) system is a highly-productive, free cordon trellissystem that is widespread in many important wine regions of the world. Weevaluated, for the first time in Argentina, the effect of different leaf-fruitratios on sensory attributes of Malbec  wines from vineyards (Clon 598) conducted inSHW spur-pruned single cordon from Bodega Trapiche in Mendoza region(Winkler=V). We imposed different leaf-fruit ratios by two ways. In experiment(1), by varying canopy height at full bloom (H: 0.45, 0.80 m and withouttopping) and in experiment (2), by varying winter pruning severity (16, 24, 32and > 32 countable buds m-2 reached by hand pruning, where >32 simulated a box pruning). We characterized wines by exhaustive chemicalanalysis (anthocyanins, tannins, phenols, acidity, malic acid, pH, alcohol,glycerol, among others) and performed a descriptive analysis of the wines. Different leaf-fruit ratios resultedin clearly different wines both at biochemist- and sensory-level. The trained sensorypanel revealed that wines from 0.80 m and without topping canopies had higherintensity of color, violet hue, acidity, alcohol and astringency than 0.45 mcanopies. These descriptors were correlated with a higher anthocianyns, malicacid, alcohol, phenolic compounds and tannins concentration. In addition, thesewines had a richer aroma profile (dry plum, red berry, red berry jam, tobacco,oak, red pepper) than 0.45 m-canopies that were identified as citric. On theother hand, the wines of the most extreme pruning levels (16 and >32 buds m-2)were similar in color intensity, violet hue, acidity, alcohol and astringency.These traits were also correlated with its corresponding biochemical variables.At aromatic level, these wines were described to have black pepper, oak, coffeeand bell pepper among others. These results suggest that the modulation ofleaf-fruit ratios by different approaches such as shoot topping or pruningseverity lead us to obtain wines with different sensory attributes. This studyallow us to adjust cultural practices intensity with the aim of producingMalbec wines with different typicity from SHW trellised-vineyards.