Microbial decontamination of mung bean sprouts by washing with plasma-activated water produced using a pilot-scale system

A pilot-scale plasma-activated water (PAW) generation system was developed, and PAW was used to wash mung bean sprouts to study the effects of PAW treatment on the inactivation of indigenous aerobic bacteria and quality of mung bean sprouts. When the mung bean sprouts were washed with PAW, the inactivation effect on indigenous bacteria increased as the treatment time increased from 1 min to 6, 10, and 30 min, with a maximum reduction of 1.5 log CFU/g. No significant differences were observed in the pH and color values of mung bean sprouts washed with PAW and those washed with distilled water or NaOCl solutions during storage for 14 days at 4°C (p>0.05). The ABTS•⁺ radical scavenging activity, total phenolic content (TPC), and total flavonoid content (TFC) of the mung bean sprouts did not initially differ among treatments. However, the PAW-washed samples showed higher TFCs than the NaOCl-washed samples after day 7 and higher ABTS•⁺ scavenging activities and TPCs on days 10 and 14 (p<0.05). These results show that the pilot-scale PAW treatment has the potential to replace conventional NaOCl washing for the microbial decontamination of mung bean sprouts.