Fig. 4.

Effects of different pulse frequency plasma treatments against foodborne pathogens on blueberries. (A) The output power corresponding to different pulse frequencies. (B) The microbial reduction after treatment with different pulse frequency plasma. (C and D) The regression curve of the output power and count reduction of E. coli and S. Typhimurium, respectively. Count reduction indicates the difference in microbial counts between the control and treatment groups. The different lowercase letters within the same group indicate significant differences (P < 0.05).