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United States Department of Agriculture

Agricultural Research Service

Research Project: IMPROVED PROCESSES FOR CUCUMBERS, CABBAGE, SWEETPOTATOES, AND PEPPERS TO MAKE HIGH QUALITY, NUTRITIOUS PRODUCTS AND REDUCE POLLUTION

Location: Food Science Research

Title: Fermentation of cucumbers brined with calcium chloride instead of sodium chloride

Authors
item McFeeters, Roger
item Perez Diaz, Ilenys

Submitted to: Journal of Food Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 19, 2010
Publication Date: April 1, 2010
Repository URL: http://hdl.handle.net/10113/42623
Citation: McFeeters, R.F., Perez Diaz, I.M. 2010. Fermentation of cucumbers brined with calcium chloride instead of sodium chloride. Journal of Food Science. 75(3):C291-C296.

Interpretive Summary: One of the major processing methods for cucumbers is to ferment and store them in large tanks for up to a year and then convert the bulk stored fermented cucumbers into processed consumer pickle products. Cucumbers are typically fermented in a 6% salt brine that also contains about 0.2% to 0.4% calcium chloride. In some cases additional salt is added up to about 12% during the storage phase. To make edible pickle products salt must be washed out of the cucumbers and discarded as waste. The discharge of the non-biodegradable salt in the waste streams of fermentation tank yard operations is a continuing problem for the pickle industry. This project tested the hypothesis that it is feasible to ferment cucumbers in brines that contain calcium chloride, but no sodium chloride and that the calcium chloride concentration required to maintain cucumber texture would be much lower than 6%. Results based upon laboratory scale cucumber fermentations indicate that 1.1% calcium chloride is sufficient to main firmness of the stored cucumbers at least as well as 6% salt and 0.4% calcium chloride. This is the first step toward doing cucumber fermentation without salt. Future work will require demonstrating that fermentation procedures that are successful in the laboratory can be transferred to the commercial fermentation tank yard setting.

Technical Abstract: Generation of waste water containing sodium chloride from cucumber fermentation tank yards could be eliminated if cucumbers were fermented in brines that did not contain this salt. To determine if this is feasible, cucumbers were fermented in brines that contained only calcium chloride to maintain firmness. Normal fermentations indicated by conversion of sugars primarily to lactic acid and lowering of pH was observed over a range of calcium chloride concentrations from 5 to 500 mM and cucumber sizes from 1A (<19 mm diameter) to 2B (32-38 mm diameter). If cucumbers contained sufficient fermentable sugars, more sugar was utilized and higher concentrations of lactic acid were produced as compared to fermentation in high sodium chloride brine. In closed containers cucumbers were microbiologically stable after the primary lactic acid fermentation. Firmness retention of fermented cucumbers stored at high temperature (45 °C) increased with increasing concentrations of calcium chloride up to 300 mM. Firmness retention was equivalent to that obtained in fermented cucumbers with 6% NaCl and 40 mM CaCl2 when cucumbers were fermented in 100 mM CaCl2. Added CaCl2 could be reduced to edible concentrations by washing it out in water for 24-48 hr similar to what is done to remove excess NaCl in current commercial practice. Though these fermentations were done in closed containers in contrast to fermentations in large open tanks in commercial tank yards, these results show there is the potential for achieving apparently normal fermentations with retention of cucumber texture sufficient for storage at ambient temperatures for a year without use of NaCl in the fermentation brine.

Last Modified: 4/23/2014