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Abstract
Lettuce and tomatoes were inoculated with 100l of a 5-strain cocktail of Escherichia coli O157:H7 or Salmonella Typhimurium DT 104 and stored at 40C overnight. Samples were then treated with neutral electrolyzed (NEO) water (155 mg/L free chlorine) in either a salad washer operating at 40 or 65 rpm or combined with ultrasonication at 130 or 210 W. Deionized water treatments served as controls. Increasing time and washing speed resulted in greater reductions of pathogens on lettuce (romaine and iceberg) treated in salad washer, while only time had a significant effect on reductions of S. Typhimurium DT 104 on tomatoes (p<0.05). For ultrasound treatments, increasing time and ultrasonic power also showed significant effects (p<0.05) on pathogen reductions. Pathogens were always inactivated in NEO water wash solutions while varying populations remained in deionized water wash solutions.