The effect of two Oenococcus oeni strains, Viniflora CiNe and CH11, with and without cinnamoyl esterase activity, respectively, on the concentrations of the hydroxycinnamic acids (HCAs) p-coumaric and ferulic acid and their respective volatile phenols, 4-ethylphenol and 4-ethylguaiacol, was investigated over six months in Cabernet Sauvignon wines inoculated with two different Brettanomyces bruxellensis strains, CBS 73 and CBS 2499. Both CiNe and CH11 showed growth and malolactic fermentation (MLF) in the wines. There were no clear growth interactions between B. bruxellensis and O. oeni. Furthermore, B. bruxellensis did not inhibit MLF by CiNe or CH11. The HCA concentrations in all wines increased until 114 days of fermentation, after which they decreased from day 114 to day 180. Wines with CiNe had the highest concentrations of HCAs throughout fermentation. However, even though CiNe degraded more of the tartaric ester-bound forms of HCAs into free HCAs, there was no clear difference in the production of volatile phenols among wines with CH11 and CiNe and the two strains of B. bruxellensis. Thus, it seems that the concentration of volatile phenols in wine depends more on strain differences of B. bruxellensis than on cinnamoyl esterase activity of O. oeni.

Funding Support: Chr. Hansen A/S, University of Copenhagen