Dielectric barrier discharge (DBD) plasma in atmospheric pressure air was used for microbial decontamination of thin sheets of dried laver, which are commonly used in kimbab preparation. Microbial contaminants namely aerobic bacteria, moulds and marine bacteria were found in sun-dried laver sheets. DBD plasma was generated at an output voltage of 30 kV AC and a frequency of 30 kHz. Upon the plasma treatment of laver, 2.5-log (99.68%), nearly 1.5-log (96.84%) and above 1.0-log (90%) unit reductions in viable counts of aerobic bacteria, marine bacteria and moulds were observed over a 10-min period, respectively. The inactivation pattern fitted well to Singh–Heldman model or pseudo first-order kinetics. Compared to control laver, no significant (P > 0.05) changes in the colour characteristics, total phenolic content and 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity were observed in plasma-treated laver. Furthermore, DBD plasma-treated laver sheets had exerted no negative impact on the sensory characteristics of kimbab and can extend the shelf life.
Dielectric barrier discharge (DBD) plasma was generated at an output voltage of 30 kV AC and a frequency of 30 kHz. Aerobic bacterial contaminants of dried laver were reduced by more than 2.5 log units upon the plasma treatment for 10 min. No significant changes were noted in the colour, phenolic content and DPPH activity of laver on the plasma treatment. DBD plasma-treated laver sheets exerted no negative impact on sensory qualities of kimbab.