Differentiation and Grouping Characteristics of Varietal Grape Musts from Penedès Region (I)

¹ Area de Nutrición y Bromatología, Facultad de Farmacia. Universidad de Barcelona. Avd. Joan XXIII, s/n, 08028 Barcelona. Spain.

This study deals with three varieties of white Vitis vinifera grapes (Macabeo, Xarel.lo, and Parellada) that are used in the production of Spanish sparkling wines. The purpose was to identify the analytical characteristics which could enable us to distinguish these three varieties, thus allowing differentiation according to vintage year (1990, 1991, 1992) or winery (A and B). In this respect, 18 must samples were identified through 75 analytical variables and submitted to analysis of variance and principal component analysis. Results show that 23 analytical variables were significantly different among varieties by analysis of variance. Principal component analysis showed that polyphenolic compounds such as S-glutathionyl-caftaric acid, epicatechin, trans-coumaric acid, trans-ferulic acid, trans coutaric/trans-caftaric ratio, total caftaric, trans and cis caftaric, and coutaric acids as well as absorbance at 280 nm, 420 nm, and 520 nm, could allow the differentiation of musts according to variety, while volatile (trans-2-hexenol, isoamyl acetate, and ethyl hexanoate) and amino acids (Gly and Tyr) components separated musts according to winery and vintage year, respectively.

Key words: differentiation, white must, characterization, variety, vintage

Submitted on May 23, 1994