Changes in Acidity, some Aroma Compounds and Sensory Properties of Frankovka Wine after Malolactic Fermentation

Stanka Herjavec, Pavica Tupajic 

Department of Enology, Faculty of Agriculture, University of Zagreb Svetošimunska cesta 25, 10000 Zagreb, Croatia

Article history:
Received April 6, 1998
Accepted June 17, 1998

Key words:
maloiactic fermentation, acids, volatile compounds, sensory properties, wine

Summary:
Changes in composition and sensory properties caused by suppressed, natural and induced malolactic fermentation (MLF) using starter cultures of lactic acid bacteria were investigated in Frankovka wine. Malic acid decomposition was completed in wines of all MLF variants and the result was lowering of total acidity by 2.6 g/L, raising of pH value of wine by 0.12 units and volatile acidity by 0.18 g/L. MLF was not accompanied with tartaric acid degradation, and citric acid concentration was lowered by 0.2 g/L. No changes were noticed in concentration of 1-propanol, isobutanol, isoamyl alcohol, hexanol and 2-phenyl ethanol. During the period of investigations, a significant concentration increase of ethyl lactate and a smaller increase of ethyl acetate were established in wines of MLF variants. Tested wines contained low concentrations of isoamyl acetate, 2-phenylethyl acetate, ethyl caproate, ethyl caprilate, diethyl succinate and acetoin. Wines of suppressed MLF were of inferior quality compared with malolactic fermented wines, while wines of natural malolactic fermentation were significantly better.