Synergistic Effects of Mild Heating and Dielectric Barrier Discharge Plasma on the Reduction of Bacillus Cereus in Red Pepper Powder

Abstract

The synergistic efficacy of a combined treatment of mild heat (MH) and dielectric barrier discharge (DBD) plasma in Bacillus cereus-contaminated red pepper powder was tested. A cocktail of three strains of B. cereus (NCCP 10623, NCCP 14579, ATCC 11778) was inoculated onto red pepper powder and then treated with MH (60 • C for 5-20 min) and DBD plasma (5-20 min). Treatment with MH and DBD plasma alone for 5-20 min resulted in reductions of 0.23-1.43 and 0.12-0.96 log CFU/g, respectively. Combined treatment with MH and DBD plasma was the most effective at reducing B. cereus counts on red pepper powder, and resulted in log-reductions of ≥6.0 log CFU/g. The largest synergistic values (4.24-4.42 log) against B. cereus in red pepper powder were obtained by the combination of 20 min MH and 5-15 min DBD plasma. The values of Hunter color "L", "a", and "b", were not significantly different from those of the untreated sample and that with the combination of MH (60 • C for 5-20 min) and DBD plasma (5-20 min). Also, no significant (p > 0.05) differences in pH values between samples were observed. Therefore, these results suggest that the combination of MH treatment and DBD plasma can be potentially utilized in the food industry to effectively inactivate B. cereus without incurring quality deterioration of red pepper powder.

The Bacillus cereus Food Infection as Multifactorial Process

“…Next to heat treatment, further non-thermal technologies for the elimination/reduction of B. cereus spores in foods were established, with the aim of significantly reducing or inactiving spores without affecting the integrity and quality of the food, alone or in combination with mild heat treatment. These are pulsed light treatment [158], electron beam irradiation [159,160], continuous ohmic heating [161][162][163], dielectric barrier discharge plasma [164], acidic electrolyzed oxidizing (EO) water and slightly acidic EO water [140,165] coupled with ultrasonication [166,167], UV treatment [168,169], microwave-combined cold plasma treatment [170] and combined treatment with germinant compounds and superheated steam [171].…”

Synergistic Effects of Combined Flavourzyme and Floating Electrode–Dielectric Barrier Discharge Plasma on Reduction of Escherichia coli Biofilms in Squid (Todarodes pacificus)

“…Additionally, if combined treatment achieves a synergistic effect, it can be considered a useful microbial decontamination technology. Jeon et al [ 45 ] reported that combined treatment with mild heat and DBD plasma to inactivate Bacillus cereus in red pepper powder resulted in a reduction of approximately 6 log CFU/g. The impact of DBD plasma on L. monocytogenes mixed-culture biofilms was assessed by quantifying the biofilms on stainless steel (SS) at various time intervals (5–60 min) following treatment.…”

“…While research on flavourzyme, recognized as a natural antimicrobial agent, remains limited, our findings could alleviate concerns regarding alterations in food quality. As a non-thermal treatment method, cold plasma can exert negligible to minimal effects on the physical, chemical, nutritional, and sensory properties of many products [ 45 ]. However, interactions between RNS and ROS generated by plasma and food components can lead to carcinogenesis, destruction of essential nutrients, and alteration of protein, lipid, and carbohydrate functionalities [ 47 ].…”