Salmonella enterica serovar Choleraesuis on fresh-cut cucumber slices after reduction treatments

Abstract

Cucumber is a popular fruit around the world and has been implicated in Salmonella food poisonings. S. Choleraesuis is a serovar that can cause pig and human infections but was rarely examined in food safety context. To investigate S. Choleraesuis behavior on cucumber slices, it was inoculated, at 104 colony forming units (CFU)/mL, onto fresh-cut cucumber slices and subjected to reduction with either high hydrostatic pressurization (HHP), hydrogen peroxide (H2O2), or Peredibacter sp. BD2GS treatment, its reduction and survival during 48 h storage at 4 °C and 25 °C were compared.Reduction tests revealed that 5% H2O2 was most effective in killing S. Choleraesuis, with 97.5% reduction after 15 min action, compared to 90.7%, 87.7%, 29.2% and 60.2% reduction rates with HHP, 2.5% H2O2, high- and low-dose BD2GS treatments, respectively.At the end of storage, contrast to no changes at 4 °C, S. Choleraesuis counts rose significantly (p < 0.05) at 25 °C. Compared to control that reached 7.1 ± 0.1 log CFU/g, HHP, 5% and 2.5% H2O2 attained 6.3 ± 0.1, 6.7 ± 0.1 and 6.4 ± 0.2 log CFU/g correspondingly, whereas high- and low-dose BD2GS attained 4.9 ± 0.1 and 5.9 ± 0.1 log CFU/g respectively. A shared growth peak of between 9 h and 12 h was noted in all treatments except high-dose BD2GS where it occurred in the first 3 h. Results of this study revealed the effectiveness of 5% H2O2 in the reduction of S. Choleraesuis, and demonstrated that if not stored properly, contaminated cucumber slices, though treated, can still have potentials to cause S. Choleraesuis outbreaks.