This study aimed to report the incidence of Alicyclobacillus and Alicyclobacillus acidoterrestris in apple and pear
flavorings (n = 42) and to assess the effect of guaiacol-producingA. acidoterrestrisstrains on apple flavorings
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 as A. acidoterrestris, and only one strain
was not able to produce guaiacol. The storage of apple flavoring 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. An A. acidoterrestris strain inoculated in flavoring 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 that flavorings may be contaminated by deteriogenic A. acidoterrestris strains 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
Alicyclobacillus was shown. To the best of the author's knowledge, this is the first report on the incidence and
fate ofAlicyclobacillus and A. acidoterrestris in flavorings.