Fermentation Cover Brine Reformulation for Cucumber Processing with Low Salt to Reduce Bloater Defect.

Reformulation of calcium chloride (CaCl2 ) cover brine for cucumber fermentation was explored as a mean to minimize the incidence of bloater defect. This study particularly focused on cover brine supplementation with calcium hydroxide (Ca[OH]2 ), sodium chloride (NaCl), and acids to enhance buffer capacity, inhibit the indigenous carbon dioxide (CO2 )- producing microbiota, and decrease the solubility of the gas. The influence of the cover brine formulations tested, on the cucumber fermentation microbiota, biochemistry, CO2 production, and bloating defect was studied using metagenetics, HPLC analysis, a portable gas analyzer and bloater index, respectively. Cover brine supplementation with Ca(OH)2 and acetic acid resulted in complete fermentations with final pH values 0.5 units higher than the un-supplemented control. Lactic acid production increased by approximately 22%, possibly inducing the observed reduction in the relative abundance of Enterobacteriaceae by 92%. Ca(OH)2 supplementation also resulted in an increased relative abundance of Leuconostocaceae by 7%, which likely contributed to the observed increment in CO2 levels by 25%. A 50% reduction on acetic acid formation was detected when cover brines were supplemented with Ca(OH)2 and 690 mM (4%) NaCl. No significant difference was observed in bloater index as the result of Ca(OH)2 or NaCl supplementation in cover brines, given that the CO2 levels remained at above the 20 mg/100 mL needed to induce the defect. It is concluded that the modified cover brine formulation containing Ca(OH)2 and NaCl enables the complete conversion of sugars, decreases production of CO2 and levels of Enterobacteriaceae, but insignificantly reduces bloater index.

PRACTICAL APPLICATION: A cucumber fermentation cover brine containing Ca(OH)2 , 0.26% CaCl2 , 345 mM (2%) NaCl, and acetic acid to pH 4.7 has a functional combination of ingredients enabling a complete conversion of sugars to lactic acid with reduced production of acetic acid and CO2 . It represents a process ready cover brine formulation with the potential to allow the manufacture of cucumber pickles with low salt, enhanced food safety, and reduce environmental impact and water usage. Pilot commercial scale cucumber fermentations brined with such ingredients are to reveal the efficacy of this process ready formulation in the presence of oxygen from air in tanks, as opposed to 3.8 L (1-US gal) closed jars in the laboratory.