Effect of low-pressure air plasma on the microbial load and physicochemical characteristics of dried laver

•Microbial contaminants such as aerobic bacteria, molds, and marine agar bacteria were detected in dried seaweed laver.•Greater than 1-log reduction in viability of contaminants was observed in 20 min of low-pressure air plasma (LPAP) exposure.•Inactivation patterns were better explained using pseudo-first-order kinetics than first-order kinetics.•Insignificant changes in color, phenolic content, 2, 2-diphenyl-1-picrylhydrazyl (DPPH) activity of laver on plasma treatment.•LPAP-exposed laver sheets exerted no negative impact on sensory characteristics of kimbab.

Low-pressure air plasma (LPAP) has not been widely used for food products surface bio-decontamination. In the present study, LPAP was used as inactivating agent against surface microbial contaminants of sun-dried laver sheets. Microbial inactivation kinetics and physicochemical characteristics of LPAP-exposed laver sheets were determined. Also, the sensory properties of kimbab (rice rolled in laver), which was roll wrapped using plasma-treated dried laver, were evaluated. LPAP was generated at the vacuum pressure of 133.3 Pa or 1Torr, and a power density of 54.1 mW/cm3. Upon LPAP-exposure, over 1-log reduction in viable cell count of aerobic bacteria was observed over a 20 min period. The microbial inactivation pattern fitted well to Singh-Heldman model or pseudo-first-order kinetics. Compared to plasma-unexposed laver, there were no changes in color characteristics, total phenolic content, and 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity of plasma-exposed laver. Furthermore, the use of LPAP-exposed laver sheets exerted minimal to no impact on sensory characteristics of kimbab.