EFFECT OF ETHANOL LEVEL IN THE PERCEPTION OF AROMA ATTRIBUTES AND THE DETECTION OF VOLATILE COMPOUNDS IN RED WINE

Abstract

ABSTRACT The sensory profile of 23 monovarietal Malbec wines were evaluated and related to the headspace composition of aroma at two alcohol levels (10.0–12.0 to 14.5–17.2% v/v). Twelve attributes were selected by quantitative descriptive analysis. At P < 0.01, two attributes showed lower aromatic intensity when alcohol level increased, and at P < 0.05, three attributes showed lower intensity; only one attribute showed higher intensity ( P < 0.05). Seventeen aroma compounds were identified using solid‐phase microextraction gas chromatography. Only one identified aroma compound showed lower contribution when alcohol level increased ( P < 0.01); another aroma was added at P < 0.05. Only one aroma showed higher contribution ( P < 0.05). Ethanol influenced the relative contribution of aroma compounds in different way – some declined while others increased. The sensorial aroma perception was also changed; when ethanol was at 14.5–17.2%, the odor was described as herbaceous instead of fruity, as was perceived at low ethanol levels. PRACTICAL APPLICATIONS The general tendency in the wine industry is the search for stronger wines with high level of alcohol. The most common reason given for this practice is that winemakers are concerned in softened tannins in the grapes on the vine, and so they have to pick grapes later in the ripening cycle. A longer hang time also produces more fruit flavors and fewer vegetal ones, up to a certain level where alcohol produces a decrease of fruity aromas. Many of these wines are considered out of balance, and dominated by ethanol‐associated attributes. The contribution of this study is to outline the changes of aroma when the alcohol in wine is raised.