Optimal experimental design to model spoilage bacteria growth in vacuum-packaged ham

- W. viridescens growth parameters were estimated with OED.
- Predictive models fitted well to the experimental data from OED.
- b and Tmin model parameters were estimated with narrow confidence intervals.
- Estimated parameters were validated for increasing/decreasing temperature profile.

Proper mathematical models with trustworthy estimated parameters are essential to accurately predict the shelf life of foodstuffs. Traditionally, many isothermal experiments are performed to estimate these parameters and their temperature dependence. Alternatively, Optimal Experimental Design (OED) of non-isothermal experiments reduces the experimental workload and costs. The objective of this study was to apply OED to estimate the growth parameters of Weissella viridescens in vacuum-packaged ham under non-isothermal conditions. Results of non-isothermal experiments (temperature ranging from 4 to 25 °C) were used for parameters estimation and independent data for model validation. Baranyi and Roberts primary model and the Square Root secondary model fitted well to the data, as verified by R2, greater than 0.986, RMSE, lower than 0.470, and by narrow confidence interval of the estimated parameters. In the model validation, a good agreement between predicted values and experimental data was observed (RMSE = 0.344, bias = 0.997 and accuracy = 1.017), indicating that the growth parameters of W. viridescens in vacuum-packaged ham were successfully estimated with OED.