A Study of Amino Acid Metabolism and the Production of Higher Alcohols and Their Esters in Sparkling Wines

The presented article is focused on the study of amino acid metabolism and the related production of fusel alcohols and their esters in the secondary fermentation of sparkling wines. The production of fusel alcohols and their esters as a by-product of the metabolism of individual amino acids during secondary fermentation and the influence of secondary fermentation with the use of individual amino acids as the only source of nitrogen was analyzed. Ten different amino acids were used. We used a control variant with the addition of ammonium hydrogen phosphate as an inorganic source of nitrogen and a control variant with an organic source of nitrogen in the form of an inactivated yeast, Saccharomyces cerevisiae, which contained all 20 amino acids in their natural ratio. The higher alcohols investigated were isoamyl alcohol, isobutanol, 2-phenylethanol, 1-propanol, 1-hexanol, and 1-butanol. The following esters of the higher alcohols were subsequently used: isoamyl acetate, hexyl acetate, phenethyl acetate, and isobutyl acetate. The individual fusel alcohols and esters were analyzed using GC-MS gas chromatography. The results pointed to different amino acid metabolisms in relation to the amount and production of fusel alcohols within the secondary fermentation and thus the sensory profile of sparkling wine.