EFFECT OF HYDROXYCINNAMIC ACIDS AND SUCCINIC ACID ON MALOLACTIC FERMENTATION OF WHITE AND RED WINES

Abstract

This study evaluates the potential of selected organic acids (ferulic, caffeic, coumaric, and succinic) to inhibit malolactic fermentation in white and red wines. Antimicrobial activity against Oenococcus oeni, Lactobacillus plantarum, and Lactobacillus brevis was assessed using growth curves and disk diffusion methods, followed by validation in real wine microsamples. While in vitro growth curves established a baseline inhibitory concentration of 5 g‧L⁻¹, testing in real wine matrices revealed that synergistic factors (lower pH and ethanol content) significantly reduce the required effective dose. The tested bacteria exhibited distinct sensitivity profiles: O. oeni was most effectively suppressed by ferulic and caffeic acids, whereas L. brevis was highly susceptible to caffeic and coumaric acids. Conversely, succinic acid provided the strongest inhibition against L. plantarum. These species-specific trends were generally confirmed by the disk diffusion method. Furthermore, in white wine microsamples, suppression was successfully demonstrated across all tested concentrations. In contrast, red wine trials exhibited a more significant dose-dependent response, where the inhibition of malolactic activity strictly increased with higher inhibitor concentrations.