The effect of hydroxycinnamic acids on the growth of wine-spoilage lactic acid bacteria

Hydroxycinnamic acids and their derivatives occur naturally in grape juice and wine. To assess their potential as natural preservatives the effect of caffeic, coumaric and ferulic acids on the growth of three wine-spoilage strains of Lactobacillus collinoides and one of Lact. brevis was studied in acid tomato broth containing 5% ethanol at pH 4.8. At concentrations of 500 and 1000 mg l^-1, all three compounds markedly inhibited growth; coumaric and ferulic acids were more effective than caffeic acid. At a concentration of 100 mg l^-1, all compounds stimulated growth. In general, the strains of Lact. collinoides were more susceptible both to inhibition and stimulation by the hydroxycinnamic acids than was the strain of Lact. brevis. The possible influence of hydroxycinnamic acids on the malolactic fermentation of wine is discussed.