Purpose: The object of this study was to compare growth kinetics of B. cereus vegetative cell and spore and S. aureus in various blanched wild vegetables stored as a function of temperature.
Methods: We used lotus roots, doraji, burdock, gosari, and chwinamul as most popular wild vegetables(roots) in Korean diet. They were blanched in boiling water for 2 min. One hundred µl of vegetative cell and spore of B. cereus and S. aureus producing Enterotoxin A were inoculated into blanched wild vegetables (roots) at 103 CFU/ml, respectively and incubated at 13, 24 and 35 °C. Lag time (LT) and specific growth rate (SGR) of B. cereus and S. aureus were calculated from Gompertz equation at each temperature.
Results: SGR of B. cereus spore was faster than that of B. cereus vegetative cell, regardless of kind of vegetables at 24 and 35 °C, while LT of B. cereus spore was longer than that of B. cereus vegetative cell, except for burdock. The SGR of S. aureus was faster than those of B. cereus at 24 and 35 °C, but no strain difference was observed at 13 °C. Compared to B. cereus, LT of S. aureus was shorter at 13 and 24 °C. B. cereus growth was not observed in gosari at 13 °C and in lotus roots at 13, 24 and 35 °C and S. aureus growth was observed in lotus roots at only 35 °C.
Significance: Proper temperature control during transportation and at retail market must be emphasized to control the growth of pathogens and spore germination. Since growth behavior of pathogens varies, more attention should be taken for storage temperature according to the kind of wild vegetables.