Inactivation of Escherichia coli O157:H7 and Salmonella on artificially or naturally contaminated mung beans (Vigna radiata L) using a stabilized oxychloro-based sanitizer

Abstract

Aims: To evaluate the efficacy of a stabilized oxychloro-based (SOC) sanitizer to decontaminate mung beans artificially or naturally contaminated with Escherichia coli O157:H7 or Salmonella.

Methods and results: Naturally contaminated beans were produced by introducing a five-strain cocktail of E. coli O157:H7 or Salmonella onto the flowers of growing mung bean plants. Escherichia coli O157:H7 was only sporadically recovered from sprout lots (three testing positive from 10 tested) derived from harvested beans. In contrast, Salmonella was recovered from 18 of 20 lots screened. Pathogens present on naturally contaminated seed could be successfully inactivated with SOC applied at 200 ppm for 24 h at 28 degrees C. SOC treatment could also decontaminate artificially inoculated mung bean batches containing different levels of contaminated seed. SOC inactivated E. coli O157:H7, but not Salmonella introduced onto damaged (scarified) beans.

Conclusions: SOC sanitizer could inactivate Salmonella or E. coli O157:H7 naturally or artificially introduced onto mung beans. However, the SOC treatment failed to inactivate Salmonella introduced onto damaged mung beans.

Significance and impact of the study: SOC sanitizer represents an effective method for decontaminating undamaged mung beans.