In general, food products are treated with gaseous and aqueous
forms of ozone. The form of ozone treatment is determined by the
types of food products being processed (Cullen et al., 2010). The
bactericidal effect of gaseous ozone on apple juice has been report-
ed by several studies. Choi et al. (2012) investigated the effect of the
solid content of apple juice on gaseous ozone against E. coli O157:H7
S. Typhimurium, and L. monocytogenes. Patil et al. (2010b) studied the
antimicrobial efficacy of gaseous ozone against E. coli in apple juice o
various pH levels. However, there have been very few research studies
investigating the bactericidal effect when apple juice is treated with
both heat and ozone gas simultaneously and their effect on quality
changes of apple juice. Therefore, in this study, we investigated the
combination or synergistic effect of ozone and heat treatments on
apple juice to inactivate E. coli O157:H7, S. Typhimurium, and L
monocytogenes. Also, changes in color and residual ozone of apple
juice after treatment were investigated.