Inactivation of Escherichia coli O157:H7 on lettuce, using low-energy X-ray irradiation.

摘要: Low-energy X-ray irradiation was assessed as a means of eliminating Escherichia coli O157:H7 on lettuce. Round-cut iceberg lettuce samples (2.54-cm diameter) were dip or spot inoculated with three-strain cocktail E. O157:H7, stored for 24 h at 4°C, and then irradiated four dose levels up to 0.25 kGy using prototype low-energy (70 kV) irradiator. survivors quantified by plating sorbitol MacConkey agar containing cefixime tellurite. Dip inoculation yielded D10-value 0.040 ± 0.001 kGy, which is 3.4 times lower than previously reported value 0.136 gamma radiation. The spot-inoculated 0.078 0.008 about twice that dip-inoculated samples. When 10 stacked leaves from both sides, 0.2 achieved the center stack surface 1 corresponding ~5-log reduction stack. Based these findi...