Inhibition of Yeast in Commercial Pickle Brines

This study investigated the inhibition of yeasts in brines from fermented cucumber pickles using 2, 4-hexadienoic (sorbic), hexanoic and (E)-3-hexenoic acids. Native yeast population and chemical composition of commercial brines were analyzed and the minimum inhibitory concentrations of inhibitors on yeast growth were established. Commercial brines were treated with 100-350 ppm of 2, 4-hexadienoic (sorbic), hexanoic and (E)-3-hexenoic acids individually and at 2.5 to 10% salt (sodium chloride) concentrations. Yeast populations in the treated brines were monitored for 30 days of incubation. Hexanoic and (E)-3-hexenoic acids at 350 ppm caused reduction in yeast populations by about 4 and 2 log CFU/ml, respectively, within 24 hours of treatment. However, when brines were treated with 2, 4-hexadienoic acid at salt concentrations of 7.5 to 10%, there were no significant differences noted in yeast inhibition between the three acids. Hexanoic and (E)-3-hexenoic acids at 200 ppm caused longer lasting inhibitory effects (30 days) on yeasts than the traditionally used 2, 4-hexadienoic acid (10 days) in fermentation brine. Thus, the hexanoic and (E)-3-hexenoic acids are potential alternatives to 2, 4-hexadienoic acid for controlling yeasts during storage of spent cucumber fermentation brines.