Antibacterial activity and mechanism of slightly acidic electrolyzed water combined with ultraviolet light against Salmonella enteritidis

This study aimed to investigate the inactivation effect and mechanism of combined treatment with slightly acidic electrolyzed water (SAEW) and ultraviolet light (UV, 253.7 nm, 10 W) (SAEW + UV) on Salmonella enteritidis. The result showed that S. enteritidis was 100% inactivated (9.21 log CFU/mL) by SAEW + UV at an available chlorine concentration (ACC) of 50 mg/L for 60 s. At the same time, the reduction value of SAEW and UV alone treatment was 6.61 and 2.27 log CFU/mL, respectively. The constructed model (R2 = 0.993) demonstrated that SAEW + UV is a highly effective germicidal method under organic matter interference (P < 0.05). The bactericidal effect was positively correlated with time and ACC, and there was also a significant interaction between time and ACC (P < 0.05). In addition, the cell membrane conductivity of S. enteritidis increased, intracellular proteins and nucleic acids exuded, intracellular ROS accumulated, and ATP decreased after SAEW + UV treatment for 60 s at ACC of 10 mg/L (P < 0.05). The results showed that SAEW + UV might disrupt the bacterial cell membrane and lead to the accumulation of intracellular ROS and a decrease of intracellular ATP, which resulted in bacterial death. Further studies are needed to understand the specific ROS production pathways of SAEW + UV on S. enteritidis.