A preliminary study of non-coloured phenolics in wines of varietal white grapes (codega, gouveio and malvasia fina): effects of grape variety, grape maturation and technology of winemaking

The effects of cultivar, grape maturation and technology of winemaking on t he levels of phenolic acids were evaluated. In all varieties, 3,4-dihydroxy benzoic, p-coumaric and caffeic acids were the predominant acids. Among the three varieties, significant differences were observed in the concentratio n of p-coumaric acid. The grape maturation only influenced the concentratio n of 3,4-dihydroxybenzoic acid. According to the technology of winemaking, significant differences could be observed in syringic, and p-coumaric acids by the induction of fermentation temperature. Comparisons of the phenolic composition, when the fermentations were conducted in stainless steel tanks and/or in oak barrels, showed differences in the concentrations of 3,4-dih ydroxybenzoic, ellagic and caffeic acids. (C) 1999 Elsevier Science Ltd. Al l rights reserved.