Flavorings as new sources of contamination by deteriogenic Alicyclobacillus of fruit juices and beverages

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-producing A. acidoterrestris strains 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 of Alicyclobacillus and A. acidoterrestris in flavorings.