of 0.12 l/min) for 0 to 10 min.While L-and b-values showed significant
increases, the a-value of apple juice samples decreased as treatment
time and concentration of ozone increased. In the case of ozone treated
freshly squeezed orange juice (Tiwari et al., 2008) and blackberry juice
(Tiwari et al., 2009a), an increase in L-value and decreases in a-and b-
values resulted. However, in our study, no significant changes of L-, a-,
and b-values were found in apple juice treated with ozone and/or
heat. The differences in color changes of fruit juices among the various
studiesmay be caused by different systems consisting of various control
parameters such as concentration, gas flow of ozone, and treatment
time. Especially, treatment time in the current study was shorter than
that of the cited studies.