Alicyclobacillus acidoterrestris in pasteurized exotic Brazilian fruit juices: Isolation, genotypic characterization and heat resistance

Abstract

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.

Modeling the effects of temperature and pH on the resistance of Alicyclobacillus acidoterrestris in conventional heat-treated fruit beverages through a meta-analysis approach

“…Because of its spoilage potential, several reports are found on the incidence of Alicyclobacillus in fruit and vegetable beverages (Siegmund and P€ ollinger-Zierler, 2006;Durak et al, 2010;Steyn et al, 2011;Walls and Chuyate, 2000;Groenewald et al, 2009;McKnight et al, 2010;Danyluk et al, 2011;Oteiza et al, 2011). Also, as a major target for fruit juice pasteurization (Tribst et al, 2009), numerous studies are found that report thermal inactivation parameters of Alicyclobacillus, i.e., the D value (time at a determined temperature required to cause one-log cycle decrease in the population of a target bacterium) and the z value (temperature increase required to result in one-log cycle decrease of Dvalue) (Splittstoesser et al, 1994;Komitopoulou et al, 1999;Bahçeci and Acar, 2007;Walls, 1997;Silva et al, 1999;Maldonado et al, 2008;de Carvalho et al, 2008;L opez et al, 2011;Alberice et al, 2012, Peña et al, 2009McKnight et al, 2010).…”

“…Also, as a major target for fruit juice pasteurization (Tribst et al, 2009), numerous studies are found that report thermal inactivation parameters of Alicyclobacillus, i.e., the D value (time at a determined temperature required to cause one-log cycle decrease in the population of a target bacterium) and the z value (temperature increase required to result in one-log cycle decrease of Dvalue) (Splittstoesser et al, 1994;Komitopoulou et al, 1999;Bahçeci and Acar, 2007;Walls, 1997;Silva et al, 1999;Maldonado et al, 2008;de Carvalho et al, 2008;L opez et al, 2011;Alberice et al, 2012, Peña et al, 2009McKnight et al, 2010). As known, D-and z-values of Alicyclobacillus are affected by the particular conditions or study characteristics (protocols, fruit and variety, Brix, pH, temperature, heating medium, culture medium, inactivation method, strains, etc.)…”

Fruit juice and puree characteristics influence enrichment requirements for real-time PCR detection of Alicyclobacillus acidoterrestris

“…Ten out of 13 samples (77%) showed background contamination of the genus Alicyclobacillus, while 7 out of the 13 samples (54%) showed the specific presence of A. acidoterrestris background contamination (Table 1). A number of reports have shown that A. acidoterrestris can be present in both fresh juices and juice concentrates (Pettipher et al 1997;Luo et al, 2004;Groenewald et al 2009;Groenewald et al 2013;McKnight et al, 2010;Wang et al, 2013). The presence of background Alicyclobacillus spp.…”

“…spoilage is a global problem in the fruit juice industry (Cagnasso et al 2010;Groenewald et al 2009, McKnight et al 2010, Walls & Chuyate 2000. Most instances of contamination have been reported in apple and orange juices (McKnight et al, 2010;Groenewald et al, 2009;Luo et al 2004). In the US juice industry alone, Alicyclobacillus spp.…”

Polarity Alteration of a Calcium Site Induces a Hydrophobic Interaction Network and Enhances Cel9A Endoglucanase Thermostability

“…Alicyclobacillus is of special interest to the fruit juice canning industry, because typical pasteurization regimens cannot inactivate its endospores (13). Alicyclobacillus acidocaldarius (ATCC 27009), a Gram-positive and thermal-acidic bacterium, first was isolated from acid hot springs in the United States (14).…”