Abstract:
Listeria innocua was used to investigate the effects of different electron beam irradiation dosages (0.00, 0.75, 1.50, 2.25, 3.00, 3.75 and 5.00 kGy) on the inactivation and physiological status of
Listeria innocua (including cell membrane permeability, leakage of intracellular ions, activity of Na
+K
+-ATPase and Ca
2+Mg
2+-ATPase, membrane potential, pH of bacterial suspension). The results show that the logarithm of total number of
Listeria innocua decreases from 8.9 to 1.4 after 5.00 kGy electron beam irradiation with
D10=0.69 kGy, and the bactericidal effect is significant. With the increase of dosage, the cell membrane permeability and the leakage of intracellular ions (K
+, Ca
2+ and Mg
2+) increase significantly. The activities of Na
+K
+-ATPase and Ca
2+Mg
2+-ATPase decrease significantly, and membrane potential and the pH of bacterial suspension also decrease significantly. According to the above results, electron beam irradiation causes the disorders of physiological metabolism of
Listeria innocua, which accelerates the death of the bacteria.