This study developed mathematical models in order to evaluate the effect of A w (Water activity) and growth temperature on @entity794 kinetic behaviour. The A w levels (0  970, 0  975, 0  983, and 0  991) of cheese were adjusted by @entity1219 ; then, Staph. aureus was inoculated on the cheese, followed by storage at 7-30    C for 72-720  h. Total bacterial and Staph. aureus cell counts were enumerated on tryptic soy agar and @entity2656 salt agar, respectively. The Baranyi model was fitted to the Staph. aureus growth data in order to calculate the maximum specific growth rate ( max; log CFU/g/h), lag phase duration (  ; h), lower asymptote (N 0; log CFU/g) and upper asymptote (N max; log CFU/g). The effects of storage temperature and A w on the kinetic parameters ( max and   ) were then further analysed with the Ratkowsky-type model and a polynomial equation, respectively. The @entity2246 ( @entity2246 ) and relative error (RE) were calculated in order to estimate the model performance. No significant effect of A w on Staph. aureus growth was observed at 7    C; thus, the Baranyi model was fitted to the growth data from 15, 25 and 30    C. The  max values (0  011-0  303 log CFU/g/h) increased (P<0  05) as the storage temperature and A w increased. In addition,    values (2  42-63  48  h) decreased (P<0  05) as storage temperature and A w increased; yet, the effect of A w on    was observed only at 15    C. The theoretical minimum storage temperature and A w were 10  15    C and 0  882, respectively. @entity2246 (0  010-1  544) and RE values (-0  131 to 0  187) from validation indicated that model performance was appropriate. Hence, these results suggest that the developed models in this study should be useful in describing the effect of temperature and A w on the growth kinetic behaviour of Staph. aureus in cheese along with the exposure assessment of Staph. aureus in cheese as well.

Kinetic behaviour of XXXX on cheese as a function of water activity and temperature.

@entity2656 :: ('MESH:D008353', 'Chemical') :: ['mannitol'] @entity1219 :: ('CHEBI:26710', 'Chemical') :: ['NaCl'] @entity794 :: ('1280', 'Species') :: ['Staphylococcus aureus'] @entity2246 :: ('MESH:D008661', 'Disease') :: ['RMSE', 'root mean square error']
@entity794 :: (1280,Species) :: ['Staphylococcus aureus']
