Purpose: The aim of this study was to develop a simple, environmental friendly, easy to perform hurdle approach to maximize decontamination efficacy of slightly acidic electrolyzed water (SAEW) on Chinese cabbage, lettuce, sesame leaf and spinach using ultrasonication (US) and water wash (WW) based on the fact that each hurdle applied might impose an increase in the antimicrobial action.
Methods: The SAEW used in this study was produced by electrolysis of a diluted hydrochloric acid (6% HCl) in a chamber without membrane at a setting of 2.5 A and 22.8 V. Effect of five different treatments; dipping in distilled water, SAEW, SAEW followed by WW, SAEW with US and SAEW with US followed by WW on the reduction of total bacteria count (TBC), Yeasts and molds (YM) and artificially inoculated pathogenic bacteria was investigated.
Results: SAEW treatment alone resulted in significant (P ≤ 0.05) reductions from 1.08 to 1.53 log CFU/g in microbial numbers compared to the control (no treatment). SAEW combined with US followed by WW resulted in 2.5, 2.54, 2.6 and 2.8 log CFU/g reductions in YM, TBC, Escherichia coli and Listeria monocytogenes on cabbage, respectively. Reductions of 2.25, 2.4, 2.5, 2.6 log CFU/g, 1.76, 1.88, 2.33, 2.4 log CFU/g and 1.97, 2.08, 2.41, 2.49 log CFU/g on lettuce, sesame leaf and spinach in YM, TBC, E. coli and L. monocytogenes were also observed.
Significance: The newly developed hurdle method is a valid approach for fresh produce sanitization. Following further investigation and optimization this approach may be a useful tool for produce decontamination in the food industry.