Effect of malolactic fermentation and ageing on the concentration of ρ-coumaric acid of Pinot Noir wine and the consequence for volatile phenol production by Brettanomyces

Background and Aims: This study compared changes in the concentration of rho-coumaric acid in wine because of enzymatic hydrolysis of rho-coutaric acid byOenocococcus oeniwith that of chemical hydrolysis during ageing. Methods and Results: Malolactic fermentation of a Pinot Noir wine with a cinnamoyl esterase-positive (CE+)O. oenistrain resulted in a significant increase in rho-coumaric acid concentration. No significant change in rho-coumaric acid concentration occurred during ageing regardless of wine pH, ethanol concentration or storage temperature. Brettanomyces bruxellensis produced a significantly higher concentration of volatile phenols in wines that underwent malolactic fermentation with the CE (+)O. oenistrain than with the CE (-) strain. Conclusions: TheO. oenistrain had significantly more impact on wine rho-coumaric acid concentration than chemical hydrolysis during ageing. Significance of the Study: The use of CE (+)O. oenistrains should be avoided in wines at risk of Brettanomyces spoilage because of an increase in the concentration of the volatile phenol precursor, rho-coumaric acid.