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Reduction of Escherichia coli O157:H7 on radish seeds by sequential application of aqueous chlorine dioxide and dry‐heat treatment
Author(s) -
Bang J.,
Kim H.,
Kim H.,
Beuchat L.R.,
Kim Y.,
Ryu J.H.
Publication year - 2011
Publication title -
letters in applied microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.698
H-Index - 110
eISSN - 1472-765X
pISSN - 0266-8254
DOI - 10.1111/j.1472-765x.2011.03125.x
Subject(s) - escherichia coli , germination , dry heat , chlorine dioxide , relative humidity , chemistry , humidity , chlorine , food science , horticulture , biology , biochemistry , materials science , organic chemistry , physics , gene , composite material , thermodynamics
Aims: To assess the effectiveness of sequential treatments of radish seeds with aqueous chlorine dioxide (ClO 2 ) and dry heat in reducing the number of Escherichia coli O157:H7. Methods and Results: Radish seeds containing E. coli O157:H7 at 5·5 log CFU g −1 were treated with 500 μg ml −1 ClO 2 for 5 min and subsequently heated at 60°C and 23% relative humidity for up to 48 h. Escherichia coli O157:H7 decreased by more than 4·8 log CFU g −1 after 12 h dry‐heat treatment. The pathogen was inactivated after 48 h dry‐heat treatment, but the germination rate of treated seeds was substantially reduced from 91·2 ± 5·0% to 68·7 ± 12·3%. Conclusions: Escherichia coli O157:H7 on radish seeds can be effectively reduced by sequential treatments with ClO 2 and dry heat. To eliminate E. coli O157:H7 on radish seeds without decreasing the germination rate, partial drying of seeds at ambient temperature before dry‐heat treatment should be investigated, and conditions for drying and dry‐heat treatment should be optimized. Significance and Impact of the study: This study showed that sequential treatment with ClO 2 and dry‐heat was effective in inactivating large numbers of E. coli O157:H7 on radish seeds. These findings will be useful when developing sanitizing strategies for seeds without compromising germination rates.