The growth kinetics of Salmonella Enteritidis in raw beef has been little studied so far. Thus,
this study aimed to clarify the growth kinetics of the pathogen in ground beef using a growth
model. When Salmonella cells inoculated at various initial doses into ground beef were incubated
at a given temperature （24℃）,
the maximum population （Nmax） of the microbe at the
stationary phase varied with the doses. This relationship was expressed with a polynomial
equation for Nmax using the initial dose. The combination of the growth model and the polynomial
equation successfully predicted Salmonella growth at a given initial dose. When Salmonella
cells inoculated in ground beef were incubated at various constant temperatures, the growth
curves of the pathogen and natural microflora （NM） were well described with the growth
model. The rate constant of growth and the Nmax values for Salmonella and NM were then
analyzed kinetically. From these results, growth curves of Salmonella and NM in ground beef
stored at dynamic temperatures were successfully predicted. Competition between Salmonella
and NM in ground beef was also found during the storage. This study could give usable information
on the growth of Salmonella and NM in ground beef at various temperatures. |
