Abstract: Bacillus cereus is a common foodborne pathogen whose spores possess strong stress resistance and can survive in powdered foods. Conventional thermal processing requires high energy input and often causes quality deterioration, highlighting the need for efficient and mild non-thermal sterilization technologies. This study developed a system integrating dielectric barrier discharge plasma with gas delivery. Under optimal conditions (gas flow rate of 10 L/min, power of 180 W, and treatment time of 8 min), the system inactivated B. cereus spores by 4.22 (lg (CFU/mL)). The Weibull and Log-Logistic models accurately described the inactivation kinetics. Increased treatment intensity led to a significant increase in the release of nucleic acids, proteins, and dipicolinic acid (DPA) (P < 0.05), indicating that plasma induces leakage of spore contents. Scanning electron microscope (SEM) and transmission electron microscope (TEM) observations further confirmed spore etching, rupture, and collapse. Pilot-scale tests showed that the system inactivated the spore by ≥ 4 (lg (CFU/mL)), without significantly affecting moisture content, color, molecular structure, or crystal morphology. The results demonstrated that low-temperature plasma technology could simultaneously achieve efficient sterilization and quality preservation of powder systems, showing promising potential for industrial application.

Key words: low-temperature plasma; Bacillus cereus; spores; thermosensitive powder; kinetic simulation; pilot-scale testing