4. Conclusions
In the treatments tested, we have achieved effective inactivation
of S. cerevisiae with a concentration of CLEO in the juices (0.02 mg/
ml) accepted by consumers. The highest inactivation of S. cerevisiae
was achieved in samples treated by combination of UST þ 0.02 mg/
ml CLEO at 50 C. Compared to the control treatment at 50 C, the
combined treatment of UST þ CLEO þ 50 C obtained a D-value
reduction of 75% for OJ and 97% for PJ. The surviving cells of S.
cerevisiae in samples treated by combination of UST þ 0.02 mg/ml
CLEO at 50 C decreased in comparison with the others treatments
during refrigerated storage, which kept the survivor population
without significant changes during this period. The S. cerevisiae
inactivation rate in the juices and later survival in refrigeration
could depend on pH and bioactive components, as anthocyanins
and tannins, of the juices. Additional research is needed to understand
the effect of bioactive components of juices in yeast inactivation
and its survival during refrigerated storage.