Predictive Model for Growth of Staphylococcus aureus in Blanched Spinach with Seasoning

The safe storage time of blanched spinach with seasoning was determined using a predictive model of Staphylococcus aureus as a function of storage temperatures (5, 15, 20, 25, 30, 35 degrees C). Storage of blanched spinach with seasoning at 5 and 15 degrees C did not show any appreciable increase in the viable populations of S. aureus. At 20, 25, 30, and 35 degrees C, a progressive increase in the viable populations of S. aureus was observed and increased more rapidly at 30 and 35 degrees C. A primary model (Gompertz model) was used to determine the determination coefficient (R-2) values of lag time (LT) and specific growth rate (SGR). R-2 values were not detected (ND) (5 degrees C), 0.9777 (15 degrees C), 0.9980 (20 degrees C), 0.9949 (25 degrees C), 0.9940 (30 degrees C), and 0.9959 (35 degrees C). A quadratic polynomial model equation could be proposed as a secondary model and was applied for lag time and SGR from primary modeling graphed as a function of storage temperature. The compatibility of the model was confirmed by calculating R-2, mean square error (MSE), bias factor (A(f)), and accuracy factor (B-f) values as static parameters. For LT and SGR, R-2 values were 0.9718 and 0.9789; MSE, 3.25 and 0.00; A(f), 1.19 and 1.12; B-f, 1.05 and 1.02, respectively. These results indicate that the predictive model for S. aureus on blanched spinach with seasoning has a high statistical compatibility. Predicting S. aureus growth under different temperature storage conditions yielded safe storage times of blanched spinach with seasoning of 10, 10, 8, and 6 h for storage temperatures of 20, 25, 30, and 35 degrees C, respectively.