Low-energy short-term cold atmospheric plasma: Controlling the inactivation efficacy of bacterial spores in powders

Surface Micro Discharge–Cold Atmospheric Pressure Plasma Processing of Common House Cricket Acheta domesticus Powder: Antimicrobial Potential and Lipid-Quality Preservation

“…Cold plasma was also proven as an effective method to inactivate spores from pathogenic bacteria on powdered food (Bußler et al, 2016;Beyrer et al, 2020a,b;Pina-Pérez et al, 2020). The inactivation of Bacillus spores embedded in a powder required a plasma power density of 10 mW/cm 2 only when generating the plasma with a surface micro discharge (SMD) device (Beyrer et al, 2020a;Pina-Pérez et al, 2020).…”

“…Cold plasma was also proven as an effective method to inactivate spores from pathogenic bacteria on powdered food (Bußler et al, 2016;Beyrer et al, 2020a,b;Pina-Pérez et al, 2020). The inactivation of Bacillus spores embedded in a powder required a plasma power density of 10 mW/cm 2 only when generating the plasma with a surface micro discharge (SMD) device (Beyrer et al, 2020a;Pina-Pérez et al, 2020). It was suggested that microorganisms be inactivated by etching through reactive oxygen and nitrogen species, altering of the cytoplasmic membrane, metabolic proteins, DNA, or photooxidation (Waskow et al, 2018;Pina-Pérez et al, 2020).…”

“…The inactivation of Bacillus spores embedded in a powder required a plasma power density of 10 mW/cm 2 only when generating the plasma with a surface micro discharge (SMD) device (Beyrer et al, 2020a;Pina-Pérez et al, 2020). It was suggested that microorganisms be inactivated by etching through reactive oxygen and nitrogen species, altering of the cytoplasmic membrane, metabolic proteins, DNA, or photooxidation (Waskow et al, 2018;Pina-Pérez et al, 2020). However, plasma does not act selectively on bacterial cells, and active plasma species can trigger chemical reactions with food matrix components, mainly carbohydrates, proteins, and lipids (Chen et al, 2012;Meinlschmidt et al, 2016;Gavahian et al, 2018;Pan et al, 2019;Sharma and Singh, 2020).…”

“…Home cricket powder was exposed to cold plasma to evaluate antimicrobial effectiveness. An SMD device (Figure 1) fully developed and constructed by the Institute of Systems engineering in collaboration with the Institute of Life Technologies, HES-SO Valais-Wallis was described in detail before (Pina-Pérez et al, 2020). In brief, plasma was ignited in ambient air at atmospheric pressure using an electrical power generator (Titan TM Series, Compact Power Company, United States) at 10 kHz frequency and a high voltage transformer (Swiss Trafo Josef Betschart AG, Switzerland).…”

“…An increased plasma density can increase the inactivation effect for B. subtilis spores on a flat, smooth surface. In contrast, the presence of particles as in starch or algae powder reduces the inactivation of spores or living cells (Beyrer et al, 2020a;Pina-Pérez et al, 2020). With insect powders, the limitations are comparable, while the protective principle might vary and can involve shadowing or/and reducing the chemical potential of the plasma via reactions with other compounds of the matrix than the microorganisms.…”