Discriminant Analysis of Sherry Wine during Biological Aging

Abstract

Eighty samples of wine from a biological aging system in the Montilla-Moriles region (southern Spain) collected during two years were analyzed. The analysis of variance for the 26 compounds studied revealed that concentrations of acetaldehyde and its derivates (diethoxyethane, acetoin, 2,3-butanediol), higher alcohols (isoamyl alcohols, propanol, isobutanol), glycerol, acetic acid, ethyl acetate, and 9 of the 15 nitrogen compounds (L-glycine, L-threonine, α-aminobutyric acid, γ-aminobutyric acid, L-proline, L-cysteine, L-lysine, urea, and ammonium ion) changed significantly during aging. A discriminant analysis with ethanol, acetaldehyde, glycerol, acetic acid, L-proline, and γ-aminobutyric acid was carried out, allowing the first three scales (fourth, third, and second criadera) to be discriminated from the first criadera and the solera. Distinguishing the latter two in chemical terms was difficult owing to the high uniformity of the wine.