2020 journal article
Contribution of Leuconostocaceae to CO 2-mediated bloater defect in cucumber fermentation *
FOOD MICROBIOLOGY, 91.
Fermented cucumber bloater defect, caused by the accumulation of microbiologically produced carbon dioxide (CO 2 ), creates significant economic losses for the pickling industry. The ability of Leuconostocaceae, indigenous to cucumber, to grow and produce CO 2 during a fermentation and cause bloater defect was evaluated. Leuconostocaceae grew and produced over 40% CO 2 in cucumber juice medium, used as a model for cucumber fermentation. The inoculation of Leuconostocaceae to 5 Log CFU/g in cucumber fermentations brined with 25 mM calcium chloride and 6 mM potassium sorbate resulted in no significant differences in bloater defect, colony counts from MRS and VRBG agar plates or the fermentation biochemistry; suggesting an inability of the inoculated bacterial species to prevail in the bioconversion. Acidified cucumbers were subjected to a fermentation inoculated with a Leuconostoc lactis starter culture after raising the pH to 5.9 ± 0.4. CO 2 was produced in the acidified cucumber fermentations to 13.6 ± 3.5% yielding a bloater index of 21.3 ± 6.4; while 8.6 ± 0.8% CO 2 and a bloater index of 5.2 ± 5.9 were observed in the non-inoculated control jars. Together the data collected demonstrate that Leuconostocaceae can produce enough CO 2 to contribute to bloater defect, if not outcompeted by the leading lactic acid bacteria in a cucumber fermentation.