This study aimed to report the incidence ofAlicyclobacillusandAlicyclobacillus acidoterrestrisin apple and pear
flavorings (n = 42) and to assess the effect of guaiacol-producingA. acidoterrestrisstrains on appleflavorings
stored at 4, 20 and 45 °C. A real-time polymerase chain reaction (RT-PCR) method was used for simultaneous
confirmation of alicyclobacilli. A total of six isolates were identified asA. acidoterrestris, and only one strain
was not able to produce guaiacol. The storage of appleflavoring at the optimum growth temperature of
A. acidoterrestris(45 °C) resulted in the reduction in the spores' counts within 30 days of storage. On the other
hand, during chilling (4 °C) and ambient storage conditions (20 °C) the counts of spores that remained stable
for up to 60 days. AnA. acidoterrestrisstrain inoculated inflavoring and further added to apple juice was able
to grow and produce guaiacol in high amounts between 1–7 days of storage at 30 °C. In the current study it
was shown thatflavorings may be contaminated by deteriogenicA. acidoterrestrisstrains that are able to survive
during storage in a wide range of temperature for long periods and further contaminate and spoil formulated fruit
juices and beverages. A novel potential source of fruit juices and beverages contamination by deteriogenic
Alicyclobacilluswas shown. To the best of the author's knowledge, this is thefirst report on the incidence and
fate ofAlicyclobacillusandA. acidoterrestrisinflavorings.