The influence of traditional and immobilized yeast on the amino-acid content of sparkling wine

Abstract

This article focuses on the effect of yeast strains, vintage, and must sugar content on the amino-acid content of sparkling wines produced by the traditional method. In the experiment, the amino-acid concentrations before and after secondary fermentation, depending on the type of yeast used (basic wine without secondary fermentation, wine fermented with immobilized yeast, and wine fermented with classical Champagne yeast) and the sugar content of the must (170, 190, and 210 g per liter), and the vintage (2010 and 2011), were evaluated. Concentrations of 20 free amino acids in 18 wine variants were analyzed by ion-exchange liquid chromatography with postcolony ninhydrin derivatization and photometric detection. Results of the study show an increase in all the amino acids represented, except ornithine, after secondary fermentation. The average content of each amino acid in the basic wine, wine fermented with immobilized yeast, and wine fermented with classical Champagne yeast was higher in the variant where classical yeast was used. In this variant, the concentrations of alanine, glutamic acid, lysine, arginine, phenylalanine, valine, and glycine were almost twice as high as in the other variants. A higher proportion of most amino acids was observed in the year 2011; only for amino acids lysine, leucine, phenylalanine, tyrosine, ornithine, histidine, and methionine was a higher concentration observed in the year 2010. A higher concentration of released amino acids was also observed in wine produced from must with a higher sugar content (21 degrees NM).