Validation of hot water and chlorine treatments to inactivate pathogens inoculated on mung bean seeds: Influence of the seed production area

Abstract

The majority of bean sprout-related outbreaks have been associated with Escherichia coli O157:H7 and Salmonella, and an effective method to inactivate these organisms on seeds prior to sprouting is important to avoid foodborne pathogen diseases. We have previously tested treatment with a combination of hot water and chlorine, and a high bactericidal effect without decreases in the germination ratio was observed on mung bean seeds produced in China. To evaluate the versatility of this treatment, the present study confirmed whether our disinfection treatment can be applied to mung bean seeds produced in another country (Myanmar). A more than 5.0 log CFU/g reduction of E. coli O157:H7 was achieved when the mung bean seeds were treated with hot water at 85 °C for 10–40 s, followed by soaking in a 2000 ppm chlorine solution for 2 h; the hot water treatment at 85 °C for 40 s followed by the chlorine treatment completely eliminated E. coli O157:H7 from the mung bean seeds. Additionally, a more than 5.0 log CFU/g reduction was obtained for Salmonella after the hot water treatment at 85 °C followed by the chlorine treatment. These treatments did not significantly affect the viability and germination of the mung bean seeds, and a sufficient yield for commercial uses was obtained.