Determination of 5-log reduction times in escherichia coli o157:h7 and lactobacillus species in cucumber juice medium with varied salt treatments

Survival of pathogenic bacteria, such as Escherichia coli O157:H7, in fermented and acidified vegetables continues to be an area of concern in the processed vegetable industry. Survival of fermentative microorganisms, such as Lactobacillus species (spp.), is desired. This study determined 5-log reduction times in 5-strain cocktails of E. coli O157:H7 and Lactobacillus spp. independently in cucumber juice media with varied salt treatments of 2% NaCl, 6% NaCl, and 1.1% CaCl2. 5-log reductions were reached for E. coli O157:H7 in 14 hours (6% NaCl) and 18 hours (1.1% CaCl2), but not observed by 18 hours in 2% NaCl. For Lactobacillus spp., a 5-log reduction was reached in 40 hours (6% NaCl) and 46 hours (2% NaCl), but not observed by 46 hours for CaCl2. There is some evidence from this study that CaCl2 could be useful for reducing E. coli O157:H7 populations while allowing survival of desirable Lactobacillus spp.