Spore suspensions of a pure culture of Alicyclobacillus acidoterrestris DSM 2498 were submitted to different heat treatments (60 degrees C for 60 min, 60 degrees C for 30 min, 70 degrees C for 20 min, 80 degrees C for 5 min, 80 degrees C for 10 min, 80 degrees C for 30 min, and boiling for 5 min) to determine the best activation conditions in orange juice. The best treatment for spore activation was shown to be 70 degrees C/20 min. Seventy-five samples of concentrated orange juice from 11 different suppliers were examined for the presence of thermophilic acid-tolerant spore formers by the most probable number technique using Bacillus acidocaldarius medium (BAM broth) and incubation at 44 degrees C for 5 days after a prior spore activation. After incubation, isolation was carried out using BAM agar medium incubating at 44 degrees C for 5 days. Typical colonies were submitted to a microscopic examination, evaluation for the presence of spores, and various biochemical tests. Of the orange juice samples examined, 14.7% were found to be positive for Alicyclobacillus. The thermal death time open tube method was used to determine the heat resistance of the spores of strains confirmed as being Alicyclobacillus. The D-values determined were in the range from 60.8 to 94.5 min at 85 degrees C, 10.0 to 20.6 min at 90 degrees C, and 2.5 to 8.7 min at 95 degrees C. The z-values were between 7.2 degrees C and 11.3 degrees C. The results demonstrated the occurrence of Alicyclobacillus in orange juice and the high heat resistance of the spores that could survive the heat treatments normally applied in the processing of orange juice.

The migration of patulin in apples was studied. A patulin-producing Penicillium expansum strain, isolated from apples, was inoculated in sound apples. Patulin was extracted and its migration was studied in each centimeter from the point of inoculation. Trimming just the rotten tissue was not enough to exclude all patulin. At 1 cm from the periphery of the rotten area, no patulin could be detected.

In this study, the population of Alicyclobacillus spp. was estimated in pasteurized exotic Brazilian fruit juices using the most probable number (MPN) technique followed by biochemical tests. Pasteurized passion fruit (n = 57) and pineapple (n = 50) juices were taken directly from Brazilian manufacturers. While Alicyclobacillus spp. was isolated from passion fruit juice, the microorganism was not found in any pineapple juice samples. A higher incidence of Alicyclobacillus was observed in samples taken in June and July (dry months in Brazil) in comparison to the other months (March, April, May and August), and the highest Alicyclobacillus counts were recovered from these samples(>23 MNP/100 mL). Sixteen (n = 16) Alicyclobacillus strains were typed using the randomly amplified polymorphic DNA method (RAPD-PCR). RAPD-PCR revealed great genetic similarity between the passion fruit juice strains and Alicyclobacillus acidoterrestris DSM 2498. The heat resistance of three isolates was determined, and the mean D(95°) (1.7 min) and z (7.6 °C) values in the passion fruit juice were not significantly different (p > 0.05) from those obtained for the DSM 2498 strain (D(95°) = 1.5 min and z = 7.1 °C). This is the first report on the isolation of A. acidoterrestris from exotic fruit juices such as passion fruit juice. It is worth pointing out the importance of applying good agricultural practices in the field and applying controls for the fruit selection and washing steps, as well as controlling the time/temperature conditions for pasteurization so as to reduce the incidence and chances of A. acidoterrestris spoilage in these juices.

As frutas e seus derivados são em geral alimentos ácidos, sendo contaminados principalmente, por bactérias lácticas, leveduras e fungos filamentosos. Neste trabalho foram isolados e identificados os microrganismos presentes em frutas e polpas de frutas e no ambiente industrial de seu processamento, sendo detectado predomínio de fungos nas amostras analisadas. As bactérias lácticas tiveram maior incidência nas superfícies analisadas. Abstract Fruits and fruit products are in general acid foods, being mainly contaminated by lactic acid bacterias, yeasts and filamentous fungi. In the present work, microorganisms present in fruits, fruit pulp and industrial environment were isolated and identified, being detected a prevalence of fungi in the samples assayed. The acid lactic bacterias were more incident at the surfaces analyzed.

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