Effects of electron beam irradiation on the variability in survivor number and duration of lag phase of four food-borne organisms

The effect of electron beam irradiation on microbial inactivation and duration of lag time of individual surviving cells of Listeria innocua, Enterococcus faecalis, Pseudomonas fluorescens and Salmonella Enteritidis has been studied. In addition, the data on variability in microbial inactivation and duration of lag phase for surviving microbes have been fitted by normal and gamma distributions, respectively. The standard deviations of survivor number and lag phase duration of individual cells were higher in irradiated batches than in non-irradiated ones. Furthermore, the more intense the irradiation treatment was, the higher the variability in both survivor number and duration of lag phase of survivors. These findings should be considered in predictive models of microbial inactivation, in risk assessment, and in adjusting preserving and/or storage conditions in the food industry.

► Microbial inactivation is variable and it depends on the inactivation conditions.
► The more intense the conditions, the more variable is the number of viable cells.
► Lag phase of individual viable cells after irradiation is variable.
► The more intense the irradiation, the more variable is the individual lag phase.