The combined efficacies of Dynashock wave ultrasound and UV-C
treatments in apple and orange juices are presented in Fig. 4. Results
showed that co-treatments with UV-C significantly reduced the t5D
values of the acid-adapted cells in both juice samples. On the other
hand, the combination of treatments appeared to have less lethality
against the test organism when applied to orange juice. When
simultaneously exposed to ultrasound treatment and UV-C irradiation,
the tlag in orange juice was reduced from 21.2 ± 0.4 for cells only
subjected to ultrasound, to 13.7 ± 0.4 min. The D values calculated
from the succeeding log-linear inactivation curves did not signifi-
cantly change from 6.7 ± 0.2 min in the ultrasound treated juice to
6.9 ± 0.1 min in the sample treated simultaneously with ultrasound
and UV-C. The calculated t5D value for orange juice simultaneously
treated with ultrasound and UV-C was significantly shorter at
48.3 ± 0.3 min, compared to that in the sample subjected to ultrasound
alone with a t5D value of 54.7 ± 0.8 min