AimsWe investigated the effect of ozone treatment of apple juice at different pH levels for inactivation of Escherichia coli O157:H7, Salmonella Typhimurium and Listeria monocytogenes. Methods and ResultsApple juice (pH 30, 40 and 50) inoculated with the three pathogens were treated with gaseous ozone (30lmin(-1) flow rate and 20-30gm(-3)) for up to 4min. Ozone treatment (4min) of pH 30 apple juice resulted in >536logCFUml(-1) reduction of E.coli O157:H7. Ozone treatment of pH 40 and 50 apple juice for 4min reduced this pathogen by 512logCFUml(-1) and 186logCFUml(-1) respectively. The combination of low pH and ozone showed a great antimicrobial effect in apple juice. Salm. Typhimurium and L.monocytogenes showed a reduction trend similar to E.coli O157:H7. There were no significant changes of colour values when apple juice was treated with ozone, except for b values. Among all ozone treated samples, the browning index was lower than that of nontreated samples and there were no significant differences in total phenolic contents. ConclusionsIn conclusion, ozone treatment of low pH apple juice was significantly effective in inactivation of foodborne pathogens while maintaining acceptable apple juice quality. Significance and Impact of the StudyThe antimicrobial effect of ozone treatment on foodborne pathogens in apple juice can be reinforced by lowering the pH of apple juice.