Department of Chemical Engineering, Rowan University, Glassboro, New Jersey, United States of America.
WuXi AppTec, Philadelphia, Pennsylvania, United States of America.
PLoS One. 2024 Nov 18;19(11):e0311232. doi: 10.1371/journal.pone.0311232. eCollection 2024.
The use of pulsed electric fields (PEF) as a nonthermal technology for the decontamination of foods is of growing interest. This study aimed to enhance the inactivation of Escherichia coli, Listeria innocua, and Salmonella enterica in Gomori buffer using a combination of nsPEF and hydrogen peroxide (H2O2). Three sub-MIC concentrations (0.1, 0.3, and 0.5%) of H2O2 and various contact times ranging from 5-45 min were tested. PEF exposures as both single (1000 pulse) and split-dose (500+500 pulse) trains were delivered via square-wave, monopolar, 600 ns pulses at 21 kV/cm and 10 Hz. We demonstrate that >5 log CFU/mL reduction can be attained from combination PEF/H2O2 treatments with a 15 min contact time for E. coli (0.1%) and a 30 min contact time for L. innocua and S. enterica (0.5%), despite ineffective results from either individual treatment alone. A 5 log reduction in microbial population is generally the lowest acceptable level in consideration of food safety and represents inactivation of 99.999% of bacteria. Split-dose PEF exposures enhance lethality for several tested conditions, indicating greater susceptibility to PEF after oxidative damage has occurred.
脉冲电场（PEF）作为一种非热技术，用于食品消毒越来越受到关注。本研究旨在通过结合纳秒级电脉冲（nsPEF）和过氧化氢（H2O2）提高 Gomori 缓冲液中大肠杆菌、无害李斯特菌和肠炎沙门氏菌的失活动能。测试了三种亚最小抑制浓度（MIC）（0.1%、0.3%和 0.5%）的 H2O2 和 5-45 分钟的不同接触时间。采用方波、单极、600ns 脉冲，施加 21kV/cm 和 10Hz 的电场强度，进行单次（1000 个脉冲）和分割剂量（500+500 个脉冲）的 nsPEF 处理。我们证明，对于大肠杆菌（0.1%），采用 15 分钟接触时间，对于无害李斯特菌和肠炎沙门氏菌（0.5%），采用 30 分钟接触时间，结合 PEF/H2O2 处理可以实现>5logCFU/mL 的减少，尽管单独使用任何一种处理方法都没有效果。在考虑食品安全的情况下，微生物种群减少 5log 通常是可接受的最低水平，这代表了 99.999%的细菌失活。分割剂量的 PEF 处理增强了几种测试条件的致死率，表明在发生氧化损伤后，对 PEF 的敏感性更高。
