HPLC Determination of Free Amino Acids Profile of Dão Red Wine: Effect of Dekkera bruxellensis Contamination

Abstract

A reversed‐phase HPLC/UV‐Vis methodology for determination of twenty free amino acids in Dão red wine is described. The sample preparation was simple, involving only a pre‐column derivatization with dabsyl chloride. The HPLC/UV‐Vis procedure is sensitive, reproducible, and accurate. The detection limit values for free amino acids were low, between 0.01 and 0.07 µg/mL, and the method was precise. As a general rule, the recovery values were high.

This methodology was applied to the evaluation of the effect of the spoilage wine yeast Dekkera bruxellensis on the Dão red wine free amino acids profile. This yeast seems to influence the free amino acids composition of the wine, including aspartic and glutamic acids, asparagine, glutamine, and isoleucine as the main affected compounds.

Keywords:

• Dão red wine
• Dekkera bruxellensis
• Free amino acids

Acknowledgments

L. R. Silva is indebted to Eng. Manuel Vieira and to Eng. Luís Cabral, from Sogrape, for supplying samples.