Growth and predictive model of Bacillus cereus on blanched spinach with or without seasoning at various temperatures

The growth of Bacillus cereus on blanched spinach with or without seasoning at various temperatures (15, 20, 25, 30, and 35°C) was investigated. The number of B. cereus on blanched spinach stored at 35°C was significantly increased and resulted in maximum populations (7.8 log CFU/g) after 10 h. However, the growth rate of B. cereus on blanched spinach with seasoning stored at 35oC was lower than on blanched spinach without seasoning. The growth rate (GR) of B. cereus on blanched spinach stored at 15°C was lower than the other temperatures. The lag time (LT) of B. cereus on blanched spinach with seasoning was longer than blanched spinach without seasoning. Primary growth models of B. cereus on blanched spinach fit well to a modified Gompertz model (blanched spinach R2 =0.98; blanched spinach with seasoning R2 =0.96). These results might be used for developing safe storage guidelines for cooked vegetable at various temperatures.