Bacillus cereus growth model established in cooked rice

ObjectiveEstablishment of growth model of Bacillus cereus in cooked rice. MethodsThe effects of temperature (10, 15, 20, 25, 30, 34, 37 and 43℃) were studied on the growth of Bacillus cereus in cooked rice. And then the SGompertz and SLogistic models were selected as the primary growth models to fit the growth curve of Bacillus cereus in cooked rice at variable storage temperatures. Using the fitness (R²), accuracy factor (A_f) and deviation factor (B_f) as evaluation index, quadratic polynomial model and square root model were selected further to fit and to establish the secondary growth models of Bacillus cereus in cooked rice.

ResultsThe SGompertz model could be better fitting the growth of Bacillus cereus at different temperatures, and therefore was chosen as the primary growth model of Bacillus cereus in cooked rice. For the developed square root model, A_f was 1.12 and 1.24, B_f was 0.99 and 1.03, R² values were 0.9537 and 0.8503; respectively. For the developed quadratic polynomial model, A_f was 1.24 and 1.11, B_f was 0.92 and 0.92, R² values were 0.9550 and 0.9462; respectively.

ConclusionThe quadratic polynomial model can well predict the growth of Bacillus cereus in cooked rice, which proves to be reliable.