School of Food Science and Environmental Health, Dublin Institute of Technology, Dublin, Ireland.
J Appl Microbiol. 2013 Mar;114(3):778-87. doi: 10.1111/jam.12087. Epub 2013 Jan 7.
The main objective of this study was to determine the inactivation efficacy of dielectric barrier discharge atmospheric cold plasma (DBD-ACP) generated inside a sealed package for Escherichia coli ATCC 25922.
A plasma discharge was generated between two circular aluminium electrodes at 40 kV. E. coli suspensions (10(7) CFU ml(-1)) in either maximum recovery diluent (MRD) or phosphate buffered saline (PBS) were treated in a 96-well microtitre plate inside a sealed package. The effects of treatment time, post-treatment storage time, either direct or indirect samples exposure to the plasma discharge and suspension media were studied. Regardless of the media tested, 20 s of direct and 45 s of indirect plasma treatment resulted in complete bacterial inactivation (7 log CFU ml(-1)). At the lower plasma treatment times (10-30 s) investigated, the effects of suspension media and mode of exposure on the inactivation efficacy were evident. The inactivation efficacy was also influenced by the post-treatment storage time.
It was demonstrated that the novel DBD-ACP can inactivate high concentrations of E. coli suspended in liquids within sealed packages in seconds.
A key advantage of this in-package nonthermal novel disinfection approach is the elimination of post-processing contamination.
本研究的主要目的是确定密封包装内介质阻挡放电大气压冷等离子体（DBD-ACP）对大肠杆菌 ATCC 25922 的灭活效果。
在 40 kV 的两个圆形铝电极之间产生等离子体放电。在密封包装内的 96 孔微量滴定板中，用最大回收稀释液（MRD）或磷酸盐缓冲盐水（PBS）处理浓度为 10(7) CFU ml(-1) 的大肠杆菌悬浮液。研究了处理时间、处理后储存时间、直接或间接样品暴露于等离子体放电以及悬浮液介质的影响。无论测试哪种介质，直接处理 20 s 和间接处理 45 s 均可实现完全细菌灭活（7 log CFU ml(-1)）。在所研究的较低等离子体处理时间（10-30 s）下，悬浮液介质和暴露模式对灭活效果的影响明显。处理后储存时间也会影响灭活效果。
证明了新型 DBD-ACP 可以在数秒内灭活密封包装内高浓度悬浮在液体中的大肠杆菌。
这种新型非热封装内消毒方法的一个主要优势是消除了后处理污染。
