Resumo

Alicyclobacillus acidoterrestris is a major challenge for fruit juice industries, because of its high chemical resistance, acidothermophilic behavior and high heat resistance. The spoilage caused by A. acidoterrestris is mainly characterized by smoky and medicinal off-flavors. Several studies have reported the incidence and ability to growth of this bacterium in a wide variety of fruit juices. However, few studies have focused on the effects of storage temperature and juice composition on the fate of A. acidoterrestris during shelf-life. Thus, the aim of this study was to assess the survival of A. acidoterrestris in clarified (grape, pear, lemon and mango) and non-clarified (tangerine, carrot and lemon) concentrated juices. In addition, the effects of lemon juice composition on A. acidoterrestris survival have been assessed. Sterile concentrate juices were inoculated with A. acidoterrestris spores (103 spores/mL), following incubation at 4 and 20 °C. For lemon juice, concentrates obtained from four different companies were collected and assessed. The results indicated no significant differences regarding the survival of A. acidoterrestris in clarified and non-clarified concentrated grape, pear, mango, tangerine and carrot juices. In these juices, A. acidoterrestris populations remained around 10^3 spores/mL during the 50 days of storage. The populations of this bacterium did not differ significantly no matter the storage temperature (4 or 20°C). On the other hand, when A. acidoterrestris spores were inoculated in lemon juices, a decrease in the counts of this bacterium were observed for the two storage conditions assessed (4 and 20°C). The populations of A. acidoterrestris were higher after 50 days of storage at 4 °C than at 20°C. In addition, the reduction in A. acidoterrestris population was higher in concentrate cloudy juice than in the clarified juice. However, no differences on the survival of this bacterium were observed among the lemon juices originated from the different companies. Further studies are being performed to gain insights on the inactivation of A. acidoterrestris as affected by different types of lemon juices (clarified and non-clarified) and their chemical composition.