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Atmospheric cold plasma is a powerful and profitable microbial decontamination technology in the food industry. The microbial load and food matrix have a great influence on the plasma inactivation effect. This study aimed to quantify the effects of initial cell concentration and soluble solids on the inactivation of yeast in apple juice by gas-phase surface discharge plasma. A computer simulation model was developed to predict the inactivation process using commercial finite element software, COMSOL Multiphysics, and the model was verified by experiments. Studies have shown that the inactivation of yeast was affected by the initial cell concentration and soluble solids. These effects were quantified by fitting equations and used as model inputs. The simulation model predicted the D-value of plasma inactivation of yeast under different discharge voltages and apple juice volume, which was verified in experiments. Therefore, the established model can be used for plasma development to predict how the food matrix affects the inactivation process, thereby providing useful and practical tools for amplifying the commercial application of plasma. • A surface discharge voltage plasma deactivation model was developed and verified. • Model correlated the cell concentration and soluble solids with inactivation rates. • The influence of discharge voltage and process capacity was predicted in the model. [ABSTRACT FROM AUTHOR]

Cold atmospheric plasma is a promising sterilization technology in the food industry. However, there are only a few studies on the process of inactivating microorganisms in liquids, and it is necessary to establish an efficient prediction model before widespread industrial application. In this study, the commercial software COMSOL was used to establish a gas phase surface discharge plasma reactor simulation model, and experiments were subsequently performed to validate the model. Results showed that increasing the initial concentration of yeast in water has a negative effect on the inactivation process. In contrast, yeast inactivation was not significantly affected by reactor diameter changes from 40 mm to 50 mm. The model showed good fit to the experimental data under various operating conditions, and the value of the parameter associated with the reaction coefficients provided insight into the process. This model can be used for process design and improvement of plasma-inactivated liquid foods. • A coupled gas-liquid mass transfer-inactivation model was developed and validated. • Different voltages were used to verify the prediction effect of the model. • The influence of initial concentration and reactor dimensions was predicted. [ABSTRACT FROM AUTHOR]