2021 年 27 巻 4 号 p. 647-656
To construct a predictive growth model of Listeria monocytogenes in ground pork, growth data were collected by real-time PCR and Listeria selective agar according to Ottaviani and Agosti (ALOA). Most probable number (MPN) was used to estimate viable numbers of L. monocytogenes at the beginning, middle, and end of the incubation period. Growth curves obtained from this study were fitted to the Baranyi and Roberts model to obtain growth parameters. Furthermore, the theoretical minimum temperature of growth was estimated by Ratkowsky's model. L. monocytogenes growth rates estimated from ALOA data were lower than those estimated by real-time PCR. Moreover, cell concentrations at all incubation temperatures were underestimated and lag phase duration at refrigeration temperature (4 °C) was overestimated by ALOA. However, the estimation from MPN more closely resembled the real-time PCR quantification results. Thus, the direct plate count tends to result in fail-dangerous prediction for bacterial risk from the model.
