The Efficiency of Atmospheric Dielectric Barrier Discharge Plasma against Escherichia coli and Bacillus cereus on Dried Laver (Porphyra tenera)

Abstract

This study investigated the effects of atmospheric dielectric barrier discharge (DBD) plasma (1.1 kV, 43 kHz, 5-30 min, N-2: 1.5 L/m) on the reduction ofEscherichia coliandBacillus cereuson dried laver. The reductions ofE. coliandB. cereusby 5, 10, 20, and 30 min of DBD plasma were 0.56 and 0.24, 0.61 and 0.66, 0.76 and 1.24, and 1.02 and 1.38 log CFU/g, respectively. The D-value ofE. coliandB. cereuswas predicted as 29.80 and 20.53 min, respectively, using the Weibull model forE. coli(R-2= 0.95) and first-order kinetics forB. cereus(R-2= 0.94). After DBD plasma 5-30 min treatment, there was no change in pH (6.20-6.21) and this value was higher than the untreated dried laver (6.08). All sensory scores in DBD plasma-treated laver were determined as >6 points. The 30 min of DBD plasma is regarded as a novel intervention for the control of potential hazardous bacteria in dried laver.