O157:H7 on pak choi seeds was greater than that on radish seeds.
The enhanced lethality of ClO2 against E. coli O157:H7 on pak choi
seeds may be due to the differences in surface morphology and
penetrability of the seeds. Fransisca and Feng (2012) treated alfalfa,
broccoli, and radish seeds containing E. coli O157:H7 with malic
acid, thiamine dilaurylsulfate, and a malic acid-thiamine dilaurylsulfate
mixture and reported that there was a negative correlation
between the surface roughness of sprout seeds and reduction
in population of E. coli O157:H7. Among the tested seed types (alfalfa,
broccoli, and radish), the surface of alfalfa seeds had the least
roughness and radish seeds showed the highest roughness. They
reported that the magnitude of reduction of E. coli O157:H7
increased as the surface roughness of seeds decreased. Although
the surface roughness of pak choi seeds was not compared with
that of radish seeds in this study, we suspect that the surface of pak
choi seeds is smoother than that of radish seeds because pak choi
(Brassica rapa) belongs to the same genus with broccoli (Brassica
oleracea)