TY - JOUR
T1 - Sanitizing radish seeds by simultaneous treatments with gaseous chlorine dioxide, high relative humidity, and mild heat
AU - Bang, Jihyun
AU - Choi, Moonhak
AU - Son, Hyeri
AU - Beuchat, Larry R.
AU - Kim, Yoonsook
AU - Kim, Hoikyung
AU - Ryu, Jee Hoon
N1 - Funding Information:
This study was supported by the High Value-added Food Technology Development Program of the Korean Institute of Planning and Evaluation for Technology in Agriculture, Forestry, Fisheries and Food (IPET) (No. 313035-03-3-HD020 ) and by a Korea University Grant .
Publisher Copyright:
© 2016
PY - 2016/11/21
Y1 - 2016/11/21
N2 - Sanitizing radish seeds intended for edible sprout production was achieved by applying simultaneous treatments with gaseous chlorine dioxide (ClO2), high relative humidity (RH, 100%), and mild heat (55 °C). Gaseous ClO2 was produced from aqueous ClO2 (0.66 ml) by mixing sulfuric acid (5% w/v) with sodium chlorite (10 mg/mL) in a sealed container (1.8 L). Greater amounts of gaseous ClO2 were measured at 23% RH (144 ppm after 6 h) than at 100% RH (66 ppm after 6 h); however, the lethal activity of gaseous ClO2 against naturally occurring mesophilic aerobic bacteria (MAB) on radish seeds was significantly enhanced at 100% RH. For example, when exposed to gaseous ClO2 at 23% RH, the number of MAB on radish seeds decreased from 3.7 log CFU/g to 2.6 log CFU/g after 6 h. However, when exposed to gaseous ClO2 at 100% RH for 6 h, the MAB population decreased to 0.7 log CFU/g after 6 h. Gaseous ClO2 was produced in higher amounts at 55 °C than at 25 °C, but decreased more rapidly over time at 55 °C than at 25 °C. The lethal activity of gaseous ClO2 against MAB on radish seeds was greater at 55 °C than at 25 °C. When radish seeds were treated with gaseous ClO2 (peak concentration: 195 ppm) at 100% RH and 55 °C, MAB were reduced to populations below the detectable level (<−0.7 log CFU/g) within 2 h without decreasing the seed germination rate (97.7%). The lethality of combined treatments against artificially inoculated Escherichia coli O157:H7 was also evaluated. When exposed to gaseous ClO2 at 100% RH and 55 °C for 6 h, the initial number of E. coli O157:H7 (3.5 log CFU/g) on radish seeds decreased to below the detection limit (0.7 log CFU/g) by direct plating but it was not eliminated from seeds. The germination rate of radish seeds was not significantly (P > 0.05) decreased after treatment for 6 h. The information reported here will be useful when developing decontamination strategies for producing microbiologically safe radish seed sprouts.
AB - Sanitizing radish seeds intended for edible sprout production was achieved by applying simultaneous treatments with gaseous chlorine dioxide (ClO2), high relative humidity (RH, 100%), and mild heat (55 °C). Gaseous ClO2 was produced from aqueous ClO2 (0.66 ml) by mixing sulfuric acid (5% w/v) with sodium chlorite (10 mg/mL) in a sealed container (1.8 L). Greater amounts of gaseous ClO2 were measured at 23% RH (144 ppm after 6 h) than at 100% RH (66 ppm after 6 h); however, the lethal activity of gaseous ClO2 against naturally occurring mesophilic aerobic bacteria (MAB) on radish seeds was significantly enhanced at 100% RH. For example, when exposed to gaseous ClO2 at 23% RH, the number of MAB on radish seeds decreased from 3.7 log CFU/g to 2.6 log CFU/g after 6 h. However, when exposed to gaseous ClO2 at 100% RH for 6 h, the MAB population decreased to 0.7 log CFU/g after 6 h. Gaseous ClO2 was produced in higher amounts at 55 °C than at 25 °C, but decreased more rapidly over time at 55 °C than at 25 °C. The lethal activity of gaseous ClO2 against MAB on radish seeds was greater at 55 °C than at 25 °C. When radish seeds were treated with gaseous ClO2 (peak concentration: 195 ppm) at 100% RH and 55 °C, MAB were reduced to populations below the detectable level (<−0.7 log CFU/g) within 2 h without decreasing the seed germination rate (97.7%). The lethality of combined treatments against artificially inoculated Escherichia coli O157:H7 was also evaluated. When exposed to gaseous ClO2 at 100% RH and 55 °C for 6 h, the initial number of E. coli O157:H7 (3.5 log CFU/g) on radish seeds decreased to below the detection limit (0.7 log CFU/g) by direct plating but it was not eliminated from seeds. The germination rate of radish seeds was not significantly (P > 0.05) decreased after treatment for 6 h. The information reported here will be useful when developing decontamination strategies for producing microbiologically safe radish seed sprouts.
KW - Escherichia coli O157:H7
KW - Gaseous chlorine dioxide
KW - High relative humidity
KW - High temperature
KW - Mesophilic aerobic bacteria
KW - Radish seed
KW - Radish sprouts
KW - Sanitizer
UR - http://www.scopus.com/inward/record.url?scp=84983637881&partnerID=8YFLogxK
U2 - 10.1016/j.ijfoodmicro.2016.08.022
DO - 10.1016/j.ijfoodmicro.2016.08.022
M3 - Article
C2 - 27569378
AN - SCOPUS:84983637881
SN - 0168-1605
VL - 237
SP - 150
EP - 156
JO - International Journal of Food Microbiology
JF - International Journal of Food Microbiology
ER -