Effect of gamma-irradiation on pathogens inoculated into ready-to-use vegetables.
Three ready-to-use vegetables, cucumber, blanched and seasoned spinach, and seasoned burdock were selected and the effects of an irradiation treatment for eliminating pathogens were investigated. The pathogens tested were Salmonella Typhimurium, Escherichia coli, Staphylococcus aureus, and Listeria ivanovii. Inoculated viable cells of S. Typhimurium and L. ivanovii into cucumber and blanched and seasoned spinach were reduced about 4 decimal points by 2 kGy of irradiation and that of S. aureus inoculated into burdock showed about 4-decimal point reduction by 1 kGy. E. coli inoculated into burdock was not detected by 1 kGy. All the bacterial contents of test pathogens into the samples were reduced to below the limit of detection by 3 kGy irradiation. The range of the D10 value was 0.28-0.42 among the four pathogens. A Salmonella mutagenicity assay (Ames test) indicated that the 10 kGy-irradiated ready-to-use vegetables did not cause any increase. The studies indicated that a low-dose irradiation (3 kGy or less) can improve the microbial safety of ready-to-use vegetables.
Young Lee
Na
N
Faculty of Biotechnology (Food Science and Technology Major), Chonbuk National University, Dukjin-Dong Jeonju 561-756, Korea.
Jo
Cheorun
C
Hwa Shin
Dong
D
Geun Kim
Wang
W
Woo Byun
Myung
M
D015169:Colony Count, Microbial; D003257:Consumer Product Safety; D004307:Dose-Response Relationship, Radiation; D004926:Escherichia coli / Q000528:radiation effects; D005506:Food Contamination / Q000517:prevention & control*; D005514:Food Irradiation; D005516:Food Microbiology; D005720:Gamma Rays; D006801:Humans; D008087:Listeria / Q000528:radiation effects; D012486:Salmonella typhimurium / Q000528:radiation effects; D013211:Staphylococcus aureus / Q000528:radiation effects; D014675:Vegetables / Q000382:microbiology* / Q000528:radiation effects