An Evaluation of Combinations of Wine Yeast andLeuconostoc oenosStrains in Malolactic Fermentation of Chardonnay Wine

Abstract

An Oregon Chardonnay juice was divided and inoculated with different yeast strains (Pasteur Champagne, Montrachet, Epernay 2, EC1118, or 10A81). Each must was subdivided and inoculated by a different strain of <i>Leuconostoc oenos</i> for malolactic fermentation (MLF). Selected MLF wines were then submitted to chemical analyses by GLC, HPLC, and GC-MS as well as aroma sensory analysis by Difference from Control method. MLF finished first in Montrachet, followed by Epernay 2 and EC1118 wines. Juices inoculated with Pasteur Champagne and 10A81 did not complete MLF. Sensory analysis showed a significant difference in aroma of MLF wines when compared to control wines of the same yeast type. HPLC analysis indicated a significant increase in acetic acid and disappearance of propionic acid in MLF wine. GLC analysis revealed a decrease in isobutyraldehyde with concomitant increase in isobutanol, suggesting the reduction of isobutyraldehyde. Also, isobutyl acetate decreased in MLF wines while isobutyraldehyde and acetate increased, suggesting the hydrolysis of isobutyl acetate. An unidentified peak occurred in all GLC analysis graphs of MLF wines but not on graphs of control wines. GC-MS analysis identified compounds in MLF wines that were not found in the control wines. These were 4-methyl-3-pentenoic acid, methyl acetate, ethyl hexanoate, hexyl acetate, 1,12-tridecadiene, hexadecanoic acid, 1,2-benzene decarboxylic acid and 2,6,10,18,22-tetracosahexae (or Farnesol).