Evaluation of household sanitizers for reducing levels of Escherichia coli on iceberg lettuce

Abstract

Diluted solutions of various household sanitizers (apple cider vinegar, white vinegar, bleach, and a reconstituted lemon juice product) were tested for their effectiveness in reducing counts of inoculated Escherichia coli and naturally present aerobic, mesophilic bacteria on lettuce. Sanitization treatments were carried out at 4 degrees C and at room temperature (ca. 21 degrees C) with and without agitation and at different exposure times (0, 1, 5, and 10 min). Of the sanitizers tested, 35% white vinegar (1.9% acetic acid) was the most effective in reducing E. coli levels (with a 5-log10 reduction after 5 min with agitation and after 10 min without agitation) and in reducing aerobic plate counts (with a >2-log10 reduction after 10 min with agitation). Lettuce samples treated with diluted household sanitizers were analyzed for consumer acceptability by sensory evaluation using a 9-point hedonic scale. The sanitized samples did not differ in acceptability (P > 0.05), except for samples treated with white vinegar. Samples treated with the white vinegar for 10 min were noticeably sour and slightly wilted in appearance. Consumer acceptability was maintained with all sanitization treatments, including those involving 35% white vinegar.