Combination of ultrasonic waves and dielectric barrier discharge plasma for the viable reduction in human norovirus while retaining the quality of raw sea squirt

Abstract

This study investigated the combined effects of ultrasonic waves treatment (UW; 44 kHz, 200 W for 30 and 60 min) and dielectric barrier discharge (DBD) plasma treatment (DP; 1.1 kV, 43 kHz, 1.5 L/min N-2 for 10, 30, and 60 min) on the viable reduction of human norovirus (HNV) GII. 4 in fresh sea squirt. The HNV was detected by RT-PCR with propidium monoazide/sarkosyl to distinguish infectious viruses from their noninfectious counterparts. Compared with UW alone (0.41-0.60 log), DP alone (0.48-1.24 log) reduced the HNV to a greater extent; additionally, the HNV was significantly reduced by increasing the combined treatment time. The UW 60 min + DP 60 min achieved a 1.97 log reduction. The pH and Hunter colors were not found to differ significantly between the separate and combined treatment. Practical Applications Our findings indicate that combined ultrasonic waves and DBD plasma treatment could serve as a potential nonthermal method for application to seafood for the reduction of human norovirus (HNV). The UW 60 min + DP 60 min may offer effective nonthermal combined treatment to reduce viable HNV GII. 4 without affecting the food quality.