Aims:  Five different isolation media, namely potato dextrose agar (PDA), orange serum agar (OSA), K agar, yeast–starch–glucose agar and Bacillus acidocaldarius medium were evaluated for the recovery of Alicyclobacillus spp. from inoculated diluted and undiluted fruit‐juice concentrates. Methods and Results:  Plates of PDA (pH 3·7), spread with vegetative cells (3·9 × 106 CFU ml−1) of Alicyclobacillus acidoterrestris from single‐strength pear juice, recovered 2·9 × 106 CFU ml−1 after 5 days at 50°C (74% recovery). The recovery of endospores from single‐strength pear juice, after a heat treatment at 80°C for 10 min, was higher on spread plates of OSA (pH 5·5) at 50°C for 5 days (97% recovery). Conclusions:  PDA (pH 3·7) and OSA (pH 5·5) at 50°C for 3–5 days recovered the highest numbers of vegative cells and endospores of Alicyclobacillus spp. from sterilized fruit juices and concentrates. Significance and Impact of the Study:  The most appropriate synthetic media for the recovery of Alicyclobacillus species from inoculated fruit juices and concentrates are shown.

The contamination of pasteurised fruit juice products by thermophilic acidophilic bacteria (TAB) has become a concern for producers. The aim of this study was to identify the bacteria present in South African fruit juices before and after pasteurisation, using polymerase chain reaction (PCR)-based denaturing gradient gel electrophoresis (DGGE). Alicyclobacillus acidoterrestris was found to be present in apple, pear, white grape and aloe vera juice. White grape juice was found to contain Alicyclobacillus pomorum, while two uncultured bacteria in the orange, apple, mango and pear juices were presumptively identified as members of the genus Bacillus, and one uncultured bacteria was identified as being closely related to Alcaligenes faecalis. The results emphasise the need for rapid and accurate detection of TAB in food products.