EFFICACY OF VINEGAR, THYME WATER AND vB_EcoM-P34 PHAGE IN INHIBITING Escherichia coli O157:H7 IN LETTUCE

Abstract

The antibacterial activity of thyme water, apple vinegar, grape vinegar, and vB_EcoM-P34 phage against Escherichia coli O157:H7 ATCC 35150 and their potential to be utilized for decontamination on lettuce were examined in this study. Lettuce samples were treated with thyme water, apple or grape vinegar solutions (10, 25, 50%), vB_EcoM-P34 phage (about 108 PFU/mL) or tap water for 30 min after inoculation of lettuce with E. coli O157:H7 at the level of 5.66 log. Depending on the concentration, vinegars and thyme water reduced the bacterial count in lettuce by between 0.78 and 2.69 logs. The most effective reduction was achieved by treatment with vB_EcoM-P34 at 3.23 log. Bacteriophage was the most suitable method for decontamination, followed by grape vinegar, apple vinegar, and thyme water at 50%. However, high concentrations of vinegars and thyme water caused a sharp odor and a slight lightening in the color of the lettuce.