Changes in Acid and Heat Resistance of Salmonella Newport and Salmonella Saintpaul Stored in Mango and Pineapple Juices (original) (raw)
2012, Journal of Food Safety
The aim of this study was to investigate survival of Salmonella Newport and Salmonella Saintpaul in simulated gastric fluid (SGF) at pH 1.9 or at 56C after storage in mango or pineapple juice at 4 or 24C for 24 h. In SGF, only Salmonella Saintpaul adapted to mango juice at 4C significantly (P < 0.05) enhanced its acid resistance with D value of 3.88 min, whereas both serovars stored in mango juice at 24C had significantly lower D values with 0.88 and 0.72 min, respectively. The D56C values of both serovars adapted to juices significantly decreased compared with nonadapted cells, except for Salmonella Newport stored in pineapple juice at 24C. Overall, two Salmonella serovars tested in this study did not show the enhanced acid or heat resistance after storage in these two tropical fruit juices, indicating that introduction of Salmonella Newport and Salmonella Saintpaul to mango and pineapple juices is unlikely to enhance their survival during gastric transit or thermal processing. PRACTICAL APPLICATIONS Salmonella spp., one of the leading causative agents of gastroenteritis, are a major public health concern in the world. It has been reported that Salmonella spp. can survive in unpasteurized orange juice or apple cider and become more resistant to subsequent exposure to acid or heat conditions.However,there is limited information in the literature on the effect of survival of Salmonella spp. in tropical fruit juices on their acid and heat resistance. This research was conducted to investigate the survivability of Salmonella Newport and Salmonella Saintpaul in simulated gastric fluid at pH 1.9 or at 56C after adaptation in mango or pineapple juice.The results of this study would enrich our understanding on the stress response of Salmonella spp. in these juices, as well as provide guidance to developing intervention technology to eliminate Salmonella Newport and Salmonella Saintpaul in mango and pineapple juices.
Related papers
African Journal of …, 2008
The vehicles usually involved in salmonellosis outbreaks are meat, eggs, poultry and milk. Recently, Salmonella outbreaks were reported in some vegetables such as tomatoes and unpasteurized juice. After inoculation of Salmonella zanzibar onto food samples, growth and survival of S. zanzibar in orange juice and salami were monitored. Our results showed that S. zanzibar is able to grow and survive in orange juice and also in salami. However, growth in salami was more important than in the case of orange juice. Storage at 4°C caused a difference in the survival curve when compared to samples (also juice and salami) incubated at room temperature. The present study demonstrated that orange juice and salami can provide a favorable environment for survival and growth of S. zanzibar in spite of their low pH values.
Journal of Food Safety, 2010
The aim of this study was to investigate the influence of acid adaptation in the survival of Salmonella Enteritidis (SE86) and Salmonella Typhimurium (ST99) during exposure to simulated gastric fluid (SGF) and in intestinal infection of Rattus norvegicus. Acid-adapted and nonadapted Salmonella strains were exposed to SGF (pH 1.5) and were inoculated by gavage in adult rats. Results indicated that acid-adapted SE86 survived significantly better (P < 0.05) than nonadapted SE86, nonadapted ST99 and acid-adapted ST99 in SGF. Nonadapted microorganisms were observed in higher counts in feces than acid-adapted strains, while acid-adapted microorganisms demonstrated higher counts in intestine samples, suggesting intestinal invasion capacity. Acid-adapted SE86 was recovered in higher counts from ileum-cecum junction than the other microorganisms.
Induction of the Viable but Non-Culturable State in Salmonella Contaminating Dried Fruit
Applied and Environmental Microbiology
Salmonella can become viable but non-culturable (VBNC) in response to environmental stressors but the induction of the VBNC state in Salmonella contaminating ready-to-eat dried fruit is poorly characterized. Dried apples, strawberries and raisins were mixed with a five-strain cocktail of Salmonella at 4% volume per weight of dried fruit at 10 9 CFU/g. The inoculated dried fruit were then dried in desiccators at 25°C until the water activity (a w ) approximated that of the uninoculated dried fruit. However, Salmonella could not be recovered after drying, not even after enrichment, suggesting a population reduction of approx. 8 log CFU/g. To assess the potential impact of storage temperature on survival, dried apples were spot-inoculated with the Salmonella cocktail, dried under ambient atmosphere at 25°C and stored at 4 and 25°C. Spot-inoculation permitted recovery of Salmonella on dried apple after drying, with the population of Salmonella decreasing progressively on dried apples st...
Loading Preview
Sorry, preview is currently unavailable. You can download the paper by clicking the button above.