An effective combined treatment using malic acid and ozone inhibits Shigella spp. on sprouts

Sanitizing efficacy of malic acid and ozone on artificially inoculated radish (Raphanus sativa) and moong bean (Phaseolus aureous) sprouts was determined against Shigella spp. Malic acid and ozone alone reduced the pathogen populations less than 3 log in both sprouts following complete immersion and spraying. Whereas, combination of both the sanitizers reduced pathogen populations significantly (P < 0.05) by 4.4 log in radish and 4.8 log in moong bean sprouts. Following treatment, antioxidant status of sprouts in terms of polyphenols, flavonoids and reducing power and free radical scavenging activities against DPPH and ABTS did not change significantly (P > 0.05); a two fold (P < 0.05) increase in DPPH radical scavenging activity in radish sprouts was observed after combined treatment. Results of our study suggest a commercially applicable intervention strategy for the control of Shigella spp. in raw sprouts.