Inactivation of Bacillus cereus Spores and Vegetative Cells in Inert Matrix and Rice Grains Using Low-Pressure Cold Plasma

• Published in: Foods Vol. 13; no. 14; p. 2223
• Main Authors: Valdez-Narváez, María Inés, Fernández-Felipe, M. Teresa, Martinez, Antonio, Rodrigo, Dolores
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01.07.2024
• Subjects: B. cereus; Bacillus cereus; Borosilicate glass; Climatic changes; Cold; Cold plasmas; Deactivation; Experimental data; Food; Food matrix; Food safety; Foodborne diseases; Grain; Heat; Inactivation; Ionization; Low pressure; low-pressure cold plasma; Microorganisms; Moisture content; Plasma; Plasma physics; Pressure effects; Rice; spore; Spores; Toxins; Vegetative cells; Water activity; Weibull model; Netherlands; Spain
• ISSN: 2304-8158; 2304-8158
• DOI: 10.3390/foods13142223

This study investigated the effects of low-pressure cold plasma on the inactivation of Bacillus cereus vegetative cells and spores in an inert matrix (borosilicate glass slide) and in rice grains, using oxygen as ionization gas. Greater reductions in B. cereus counts were observed in vegetative cells rather than spores. The experimental data obtained show that both the power of the plasma treatment and the matrix proved to be determining factors in the inactivation of both the spores and vegetative cells of B. cereus. To characterize the inactivation of B. cereus, experimental data were accurately fitted to the Weibull model. A significant decrease in parameter “a”, representing resistance to treatment, was confirmed with treatment intensification. Furthermore, significant differences in the “a” value were observed between spores in inert and food matrices, suggesting the additional protective role of the food matrix for B. cereus spores. These results demonstrate the importance of considering matrix effects in plasma treatment to ensure the effective inactivation of pathogenic microorganisms, particularly in foods with low water activity, such as rice. This approach contributes to mitigating the impact of foodborne illnesses caused by pathogenic microorganisms.