Assessment of Bacillus cereus concentration in soy-based beverages prepared from cold plasma-decontaminated raw materials

This study aimed to develop industrial exposure assessment models to determine the contamination level of Bacillus cereus in soy-based beverages formulated from raw materials (soy flour and soy protein) decontaminated by using cold plasma technology. The assessment comprised two stages: i) cold plasma sanitization of raw materials and ii) subsequent storage under cold chain break conditions (20 °C) of beverages formulated by using the sanitized raw material. B. cereus spores were inoculated into the raw materials and treated with synthetic air plasma (0.80 mbar, 300 W) at varying exposure times. Inactivation curves were modeled using the Weibull distribution function. To assess the growth, the Baranyi and Roberts model was used incorporating data from previous studies. The modular industrial exposure assessment models were used to perform Monte Carlo simulations including different initial contamination levels (10 2 to 10 4 CFU/g) and two plasma performance criteria (1 and 2 log reductions). Although all units remained contaminated, plasma treatment prevented B. cereus from reaching the infective dose in the formulated beverages with sanitized raw material, in all evaluated scenarios. Conversely, drinks formulated with untreated raw materials exceeded that infective dose at the highest contamination level. Consequently, cold plasma was found to be useful for the sanitization of raw materials used for formulate beverages, maintaining a safe level of B. cereus under cold chain break conditions. Cold plasma could be integrated into a hurdle technology approach to enhance food safety standards.