Differentiation of red winemaking technologies by phenolic and volatile composition

Phenolic and volatile compounds play an important role in enology owing to their contribution to wine sensory properties and to their participation in various phenomena during winemaking and aging process. The objective of this work was to establish the relationship between the phenolic and volatile composition and the type of winemaking technologies. Four Castelao (Vitis vinifera, cv.) red wines were made by different winemaking technologies: carbonic maceration (maceration temperature 35 degreesC and maceration time 21 days), stem-contact fermentation (maceration time 7 and 21 days) and non stem-contact fermentation (maceration time 7 days). Phenolic compounds were analyzed by liquid chromatography (LC) and spectrophotometric methods. The volatile composition was analyzed by HRGC and by gas chromatography-mass spectrometry (GC-MS). Multivariate analysis, i.e., clustering and principal component analysis (PCA), was applied to the results of phenolic and volatile composition. The carbonic maceration wine had less color intensity, lower concentrations of phenolic compounds and of 1-hexanol, 2-phenylethanol, diethyl succinate, and diethyl malate, but higher concentrations of benzyl alcohol and ethyl lactate than the skin fermentation wines. Stems are an important source of polyphenols, but increasing maceration time decreased both total and some individual anthocyanins. The volatile composition was not significantly affected by the presence of stems. Phenolic and volatile composition appeared a powerful tool to distinguish the wines made by different winemaking technologies, particularly to distinguish the carbonic maceration wine from the skin fermentation wines. (C) 2004 Elsevier B.V. All rights reserved.